All Weather Inc AWOS 3000 Specifications

Automated Weather Observing System
Maintenance
Manual
3000-027
Rev. E
All Weather Inc. • 1165 National Drive • Sacramento, CA 95834 • USA • 800.824.5873 • www.allweatherinc.com
Copyright © 2011, All Weather, Inc.
All Rights Reserved. The information contained herein is proprietary and is provided solely for the
purpose of allowing customers to operate and/or service All Weather, Inc. manufactured equipment
and is not to be released, reproduced, or used for any other purpose without written permission of All
Weather, Inc.
Throughout this manual, trademarked names might be used. Rather than put a trademark (™) symbol in
every occurrence of a trademarked name, we state herein that we are using the names only in an editorial
fashion and to the benefit of the trademark owner, and with no intention of infringement. All Weather,
Inc. and the All Weather, Inc. logo are trademarks of All Weather, Inc.
Disclaimer
The information and specifications described in this manual are subject to change without notice.
Latest Manual Version
For the latest version of this manual, see the Product Manuals page under Reference on our web site at
www.allweatherinc.com/.
All Weather, Inc.
1165 National Drive
Sacramento, CA 95834
Tel.: (916) 928-1000
Fax: (916) 928-1165
Contact Customer Service

Phone support is available from 8:00am - 4:30pm PT, Monday through Friday. Call 916-928-1000
and ask for “Service.”

Online support is available by filling out a request at www.allweatherinc.com/customer/support.html

E-mail your support request to support@allweatherinc.com
AWOS 3000 MAINTENANCE
Table of Contents
1. OVERVIEW................................................................................................................................................................................. 1 1.1 System Description............................................................................................................................................................... 1 1.2 System Performance Parameters ........................................................................................................................................ 1 1.3 Scheduled Maintenance ....................................................................................................................................................... 1 1.4 Site Preparation .................................................................................................................................................................... 2 1.5 Installation & Checkout Manual ............................................................................................................................................ 2 1.6 Operating Instructions .......................................................................................................................................................... 2 1.7 Training Program .................................................................................................................................................................. 2 1.8 AWOS Field Replaceable Units (FRUs) ............................................................................................................................... 2 2. MONTHLY PROCEDURES ........................................................................................................................................................ 7 2.1 Monthly Maintenance Tools and Supplies ............................................................................................................................ 7 2.2 General Maintenance ........................................................................................................................................................... 8 2.3 Specific Maintenance ........................................................................................................................................................... 8 2.4 Record AWOS Observations .............................................................................................................................................. 14 3. TRIANNUAL PROCEDURES................................................................................................................................................... 15 3.1 Triannual Maintenance Test Equipment ............................................................................................................................. 15 3.2 Triannual Maintenance Tools and Supplies ....................................................................................................................... 16 3.3 Perform Monthly Procedures .............................................................................................................................................. 16 3.4 Specific Triannual Maintenance ......................................................................................................................................... 16 4. ANNUAL SYSTEM REVALIDATION ....................................................................................................................................... 24 4.1 Annual Revalidation Test Equipment ................................................................................................................................. 24 4.2 Annual Revalidation Tools and Supplies ............................................................................................................................ 25 4.3 Perform Monthly and Triannual Procedures ....................................................................................................................... 25 4.4 Specific Annual Maintenance ............................................................................................................................................. 25 5. TROUBLESHOOTING GUIDE ................................................................................................................................................. 37 5.1 Central Data Processor (CDP) ........................................................................................................................................... 38 5.2 Temperature/Relative Humidity/Barometric Pressure Sensors .......................................................................................... 39 5.3 Wind Speed Sensors .......................................................................................................................................................... 40 5.4 Wind Direction Sensors ...................................................................................................................................................... 41 5.5 Visibility Sensor .................................................................................................................................................................. 42 5.6 Ceilometer .......................................................................................................................................................................... 43 5.7 Present Weather and Thunderstorm/Lightning Sensors .................................................................................................... 44 5.8 Freezing Rain Sensor ......................................................................................................................................................... 45 5.9 Data Networking ................................................................................................................................................................. 46 6. FORMS ..................................................................................................................................................................................... 47 1
O V E R V I E W
Chapter
Overview
This manual provides instructions for inspecting and revalidating All Weather, Inc. (AWI)
AWOS 3000 systems. It includes complete maintenance instructions, as well as forms for
recording the results of monthly, triannual, and annual maintenance procedures.
1.1 System Description
A full description of the AWOS 3000 can be found in the AWOS 3000 System User’s Manual
(3000-001), which includes system drawings, descriptions of software operation and interfaces,
and the available sensor and component configurations of an AWOS.
This manual covers all AWOS systems. Please refer to the AWOS 3000 System User’s Manual
(3000-001) for the configuration details for each AWOS model.
1.2 System Performance Parameters
System performance parameters are given in the individual sensor and component manuals.
Detailed specifications are provided for each component. An overall description of the AWOS
system's performance parameters can be found in the AWOS 3000 System User’s Manual
(3000-001).
1.3 Scheduled Maintenance
Scheduled maintenance is performed on AWOS systems at three intervals: monthly, triannually,
and annually. Records of these procedures, along with any adjustments or repairs made, are
recorded on the maintenance forms at the back of this manual.
1.3.1 Data Recording Forms
Three data recording forms are included with this manual — the Monthly Technical Performance
Record, the Triannual Technical Performance Record, and the Annual Technical Performance
Record. These forms are used during periodic maintenance, and include space to record the
results of scheduled maintenance procedures. In addition to annual revalidation, the Annual
Technical Performance Record is to be completed at system commissioning and after major
repair work. These master forms should be copied and sufficient copies stored at a convenient
location in each site's Facility Reference Data File (FRDF).
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AWOS 3000 MAINTENANCE
1.4 Site Preparation
Individual Site Preparation Manuals are available for each AWOS configuration. Site
Preparation Manuals contain the instructions and drawings necessary for completing trenching,
foundation construction, and other site preparation work required prior to installation of an
AWOS.
1.5 Installation & Checkout Manual
The AWOS 3000 Installation Manual (3000-017) provides complete installation and checkout
procedures for all AWOS systems.
1.6 Operating Instructions
Overall system operating instructions can be found in the AWOS 3000 System User’s Manual
(3000-001). Operating instructions for individual sensors and components can be found in their
respective manuals. The Operation chapter of each manual provides full instructions for using a
component and for interpreting that instrument’s data.
1.7 Training Program
AWOS technicians are fully qualified in electronic and electrical applications, and have comprehensive knowledge of the operations, testing, and maintenance of the AWOS to the board
component level. They have the capabilities to evaluate and make recommendations for system
component changes that would enhance the reliability or functionality of the AWOS.
AWI provides a comprehensive training and certification program for all AWOS technicians to
ensure thorough knowledge and competence in working with AWOS systems. The training is
documented in the AWOS 3000 Maintenance Training Course (3000-044).
1.8 AWOS Field Replaceable Units (FRUs)
When an AWOS component or sensor fails, consult the troubleshooting chart in Chapter Error!
Reference source not found. to identify the Field-Replaceable Unit (FRU) to replace. If the
problem persists or cannot be narrowed down from the troubleshooting chart, please contact All
Weather, Inc. Customer Service.
2
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AWOS 3000 MAINTENANCE
Table 1 lists the lowest replaceable units (FRUs) for the AWOS 3000. When a sensor is replaced,
the annual procedure for that sensor must be performed.
3
O V E R V I E W
AWOS 3000 MAINTENANCE
Table 1. AWOS FRUs
Description
Model/Part No.
Option
DATA COLLECTION PLATFORM
PCB AWOS Data Collection
Main Daughter Board
DCP Firmware
Sensor Interface Controller
Ceilometer Interface Firmware
Ultrasonic Wind Interface Firmware
Freezing Rain Interface Firmware
Power Supply Assembly
Fuse 0.5 A Slow Blow
Fuse 5 A Slow Blow
Fuse 10 A Slow Blow
AC Power PCB Assembly
Data Link Radio
Barometric Pressure Sensor*
Quad Plate Pressure Port
*
M404804
M487094
M488290-00
M404806
M469075
M469076-00
M469066
M438210-00
M442060
M442070
M442071
M404802
20980-A
7190
M105037

The Model 7190 Barometric Pressure Sensor is installed on the Data Collection Platform.
CENTRAL DATA PLATFORM
CDP
Monitor
CPU Board
Keyboard/Mouse
DVD/CD Drive
Power Supply
Telephone Modem
Microphone
Data Link Radio
Ground-to-Air Radio
GPS Receiver
3000
M482179-00
M406186-00
M406187-00
M406190-00
M438222-00
M406159-00
20906
20980-A
1792
M406167-00
AWOS 3000 Software Installation CD
M595814-00-060
UPS
20913-F
UPS Batteries (3 required per UPS)
Minuteman 37000007

SENSORS
Wind Direction Sensor
Tail Vane
Potentiometer/Shaft Assembly
Bearing Kit
Heater
Wind Speed Sensor
Cup Assembly
Photon Chopper Assembly
Bearing Kit
Heater
2020
T802000
T170522
M488140
20201
2030
T800303
T801600
M488141
20201
4


O V E R V I E W
AWOS 3000 MAINTENANCE
Description
Model/Part No.
Ultrasonic Wind Sensor (unheated)
RS-422 Converter
Ultrasonic Wind Sensor (heated)
RS-422 Converter
Fuse 4 A
Ultrasonic Wind Sensor (high heat)
RS-422 Converter
Fuse 10 A
Motor Aspirated Radiation Shield (MARS)
Fan
Temperature Sensor/RH Sensor
Rain Gauge (unheated)
Rain Gauge (heated)
Visibility Sensor
Emitter Head Assembly
Detector Head Assembly
Controller Board
AC Interface
Firmware
Fuse 10 A Slow Blow
Fuse 5 A Slow Blow
Fuse 2 A
Fuse 4 A
Fuse 0.5 A
Ambient Light Sensor
Day/Night Detector
Cloud Height Sensor
Optical and Laser Module
DAQ & Power PCB
Blower, 110 V AC
Power Supply
Communication Cable
Fuse 5 x 20 mm, 5 A, 250 V AC
Fuse 5 x 20 mm, 10 A, 250 V AC
Desiccant
Battery
Present Weather Sensor
AC Interface
Fuse 5 A Slow Blow
Fuse 10 A Slow Blow
Heater Power Supply
Sensor Interface Controller
Present Weather Firmware EPROM
5
2040
M438205-00
2040-H
M438205-00
M442105-00
2040-HH
M438205-00
M442106-00
8190
M444021
5190
6011-A
6021-A
8364-E
M105061-00
M105060-00
M404811
M404802
M469058
M442071
M442070
M442046
M442048
M442057
M488171
M403326-00
8339-FAA
M403434-01
M404848-02
83396-00
M438200-00
M491742-00
M442088-00
M442089-00
M028181-00
83395-00
6490
M404802
M442070
M442071
M438158
M404806
M469053
Option
O V E R V I E W
AWOS 3000 MAINTENANCE
Description
Model/Part No.
Thunderstorm/Lightning Sensor
AC Interface
Sensor Interface Controller
Firmware
Power Supply
Fuse 5 A Slow Blow
Fuse 10 A Slow Blow
Freezing Rain Sensor
Communication Cable
Option
6500
M404802
M404806
M469067
M438152
M442070
M442071
6495
M491740
MISCELLANEOUS EQUIPMENT
Printer
Printer Ribbon
UHF/VHF Antenna
20910-A
20911
M489103
6

M O N T H L Y
2
P R O C E D U R E S
Chapter
Monthly Procedures
AWOS monthly maintenance consists of a general system check and cleaning of sensor optics.
Follow the procedures below, take any required corrective action, and record the results on the
Monthly Technical Performance Record.
The person performing the monthly maintenance procedures is not required to have any FAA
certification. However, the monthly maintenance should be performed by an individual who has
attended the User and Maintenance training given by AWI and documented in the AWOS 3000
Maintenance Training Course (3000-044). This training will familiarize the person with the
basic mechanical and electrical orientation needed to perform monthly maintenance.
2.1 Monthly Maintenance Tools and Supplies
The following list gives the tools and supplies required during monthly maintenance of the
AWOS.
Description
Part/Model No.
Assorted Hand Tools
Clean Dry Cloth
Water & Spray Bottle
Lightweight Greaseless
Oil
isopropyl Alcohol
RTV sealant
n/a
n/a
n/a
n/a
Lint free
n/a
n/a
(e.g., 3-in-1 or equivalent)
n/a
RTV 162
Business Card
n/a
Paint
n/a
Soap
n/a
Sandpaper or Emery
Cloth
n/a
7
Specifications
70%-100%
n/a
Business card, credit card, driver’s
license, one U.S. dollar or
equivalent in weight and size.
White, outdoor enamel. Krylon and
Rustoleum are two popular brands
Mild – non-scented. Ivory brand
soap bars work well.
120-150 grit suitable for removing
surface rust or corrosion.
M O N T H L Y
P R O C E D U R E S
AWOS 3000 MAINTENANCE
2.2 General Maintenance
Verify that obstruction lights on the tower are checked. This is generally the responsibility of the
airport operator, but since airport personnel will likely be performing the remaining maintenance, it
is reasonable that airport personnel confirm the operation of the obstruction lights. The overall
condition of the sensor site, including weed heights, things that might interfere with a sensor’s
ability to perform properly, and the presence of items that may encroach on the siting criteria
parameters should also be reviewed at this time.
Inspect all mounting hardware and external surfaces and cable assemblies.
If surfaces require cleaning, use mild soap and water. If surfaces are rusty, preserve them by
sanding off the rust and applying paint.
If any cables have developed stress cracks or exhibit other damage that appears to compromise
the integrity of the outer protective sheath, report the problem immediately – do not attempt to
service any electrical cable.
2.3 Specific Maintenance
2.3.1 Model 1190 Data Collection Platform
1. Verify that all cables are connected and in good condition.
2. Press the maintenance switch (SW3).
2.3.2 Model 7190 Dual Digital Barometer
1. Visually check the pressure port and clear any debris from within the plate area.
2.3.3 Model 2020 Wind Direction Sensor
1. Visually verify that the vane is moving freely.
2. Verify that the displayed values on the DCP are not static. A small breeze will be necessary.
(This is an indication that the internals of the sensors are working properly and are
communicating their values to the DCP appropriately.)
3. Verify that the sensor is clear of large debris, such as bird nests.
2.3.4 Model 2030 Wind Speed Sensor
1. Visually verify that the cups are moving freely.
2. Verify that the displayed values on the DCP are not static. A small breeze will be necessary.
(This is an indication that the internals of the sensors are working properly and are
communicating their values to the DCP appropriately.)
3. Verify that the sensor is clear of large debris, such as bird nests.
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M O N T H L Y
P R O C E D U R E S
AWOS 3000 MAINTENANCE
2.3.5 Model 2040 Ultrasonic Wind Sensor
1. Verify that the displayed values on the DCP are not static. A small breeze will be necessary.
(This is an indication that the internals of the sensors are working properly and are
communicating their values to the DCP appropriately.)
2. Verify that the sensor is clear of large debris, such as bird nests.
2.3.6 Model 8190 MARS
Maintenance of the MARS is generally limited to periodic cleaning and occasional repainting of
exterior surfaces.
1. Check the 8190 air inlet (the narrow end of the MARS) for obstructions and debris.
2. Remove obstructions and debris as necessary.
3. Check the MARS for insect activity (cobwebs, hornet's nests, etc.), as well as birds' nests,
and clean out any debris.
4. The exterior surfaces of the MARS should be free of dirt at all times to prevent internal
heating of the probe. Clean the surfaces regularly with water and mild soap. Repaint the
exterior surfaces as required Surfaces may be scuffed with sand paper to clean them and
encourage better paint adhesion.
5. During regular maintenance, check the fan housing for signs of corrosion. Clean the
housing and protective grate as necessary. Use only a damp cloth. Do not squirt water
into the fan.
6. The inside of the enclosure may also need to be cleaned of excessive dirt drawn in by the
fan. Use only a damp cloth. Do not use soap.
7. Check all cables for signs of wear or damage, especially in areas with high velocity
winds. Check all mounting hardware for corrosion or looseness, and repair or replace as
required. If any cables have developed stress cracks or exhibit other damage that appears
to compromise the integrity of the outer protective sheath, report the problem
immediately – do not attempt to service any electrical cable.
8. Check the fan for noise that could be a sign of worn bearings.
9. If the MARS fan is in need of repair, report the problem
10. Using a small light-weight object, such as a business card, credit card, driver’s license or
one dollar bill, test to ensure the MARS fan is producing adequate air flow. Place the
business card over the small end of the MARS (the air inlet). The card should be held in
place by the suction produced by the fan.
11. If the MARS fan is in need of repair, report the problem.
9
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AWOS 3000 MAINTENANCE
2.3.7 Model 6011 Rain Gauge
1. Remove the screen from the funnel of the rain gauge and gently tap the screen to free any
dirt or debris.
2. Check the rain gauge funnel for insect activity (cobwebs, hornet's nests, etc.), as well as
birds' nests, and clean out any debris. Be sure to check underneath the instrument as well.
3. Water and a damp cloth can be used to clean the rain gauge as needed. Do not use soap.
4. Never paint the rain gauge. If repairs are needed, report the problem.
5. Reinstall the screen.
2.3.8 Model 6021 Heated Rain and Snow Gauge
1. Remove the screen from the funnel of the rain gauge and gently tap the screen to free any
dirt or debris.
2. Check the rain gauge funnel for insect activity (cobwebs, hornet's nests, etc.), as well as
birds' nests, and clean out any debris. Be sure to check underneath the instrument as well.
3. Water and a damp cloth can be used to clean the rain gauge as needed. Do not use soap.
4. Never paint the rain gauge.
5. Reinstall the screen
6. If the ambient temperature is below 40°F, feel the rain gauge cover to check operation of
the heaters. If they are working, the outer cover should be warm to the touch.
7. If repairs are needed, report the problem.
2.3.9 Model 8364-E Visibility Sensor
1. Clean the Visibility Sensor windows using a soft cloth and water.
2. Clean the Day/Night Sensor optics.
10
M O N T H L Y
P R O C E D U R E S
AWOS 3000 MAINTENANCE
2.3.10 Model 8339 Ceilometer
CAUTION
Use clean water and a soft cloth to clean the windows. Commercial cleaners
containing ammonia will degrade the optical coating on the windows,
resulting in degraded sensitivity (higher altitude clouds will no longer be
detected).
1. Clean the transceiver windows at least once per month (more frequently if local conditions warrant), or when the status message so indicates. Note that a dirty window warning
message may also appear during rain, snow, and fog conditions, whenever the internal
electronics measure a certain level of window opacity.
2. Each time the windows are cleaned, check blower operation by covering the receiver
window, shown in Figure 1, with a diffuse reflective object (such as a sheet of white
paper) and verifying that the blower turns on. This may take up to 30 seconds.
Figure 1. The right hand side is the receiver
11
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AWOS 3000 MAINTENANCE
2.3.11 Model 6490 Present Weather Sensor
1. With a clean finger, touch the lenses in front of the disc-shaped heaters which are bonded
to the upper and lower inside surface of lenses. The lens surfaces should be slightly
warmer to the touch than the ambient temperature.
2. If the lens is not warm to the touch, the sensor must be repaired or replaced.
3. Clean the lenses by first spraying water on the lens and then wiping gently with a lint-free
cloth to prevent scratching the glass optics.
2.3.12 Model 6500 Thunderstorm/Lightning Sensor
1. Check the antenna for dents, cracks, or punctures.
2. Remove all dirt and grease from surface areas using a soft cloth moistened with mild
soap and water.
2.3.13 Model 6495 Freezing Rain Sensor
The freezing rain sensor probe assembly will be hot if the sensor recently
WARNING
completed a deice cycle. Ensure that the probe assembly has cooled before
cleaning the probe. While in the deice mode, the probe will radiate a
significant amount of heat. This can be observed by placing a hand close to,
but not on, the sensor probe. Always avoid direct contact of the probe with
skin to avoid a potential burn hazard.
CAUTION
Do not touch the probe with bare hands, as oil residue from skin will affect
the performance of the sensor.
1. Visually inspect the surface of the probe for contaminants such as dirt, oil, fingerprints,
etc.
2. If any contaminants are present, clean the probe using isopropyl alcohol and a soft cotton
cloth.
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AWOS 3000 MAINTENANCE
2.3.14 Central Data Processor (CDP)
1. Check display operation.
2. Check keyboard operation.
3. Check printer operation as necessary. If the printer has been printing normally during the
past hour, it is not necessary to perform this test.
4. Log in as an operator
5. Go to the File > Printer Setup menu
6. Click the “Print Test Page” button and verify that the test page was printed
7. Check the printer ribbon and replace as necessary.
8. Check the printer paper and replace as necessary.
9. Check microphone operation by recording a voice remark. Delete the remark when done.
To delete a voice remark, record a short (approximately one second), empty remark over
it, and set “enabled” to “off.”
10. Check dial-up telephone operation by dialing the CDP from an outside line.
11. Verify VHF radio operation by listening to the AWOS voice output over a remote
receiver.
12. Check the system clock against a known standard. If the difference is greater than 10
seconds, report the problem.
13. Check speaker operation.
14. Check UPS operation by disconnecting the AWOS power cable. The AWOS should not
shut down.
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AWOS 3000 MAINTENANCE
2.4 Record AWOS Observations
The final portion of the AWOS Monthly Technical Performance Record provides room to record
AWOS readings and to note any irregularities. This provides a written snapshot in addition to the
logs generated automatically.

Time and Date

Thunderstorm/Lightning

Wind Direction

Freezing Rain

Wind Speed

Temperature

Visibility

Dew Point

Sky Condition (Clouds)

Altimeter Setting

Precipitation


Note any "missing" parameters or
any other obvious failures
Present Weather
14
T R I A N N U A L
3
P R O C E D U R E S
Chapter
Triannual Procedures
AWOS triannual maintenance is performed three times per year. Follow the procedures below,
take any required corrective action, and record the results on the Triannual Technical
Performance Record.
Only an FAA authorized technician of record for the site may perform triannual procedures.
3.1 Triannual Maintenance Test Equipment
The following list gives the test equipment required during triannual maintenance of the AWOS.
This is in addition to that required for monthly procedures.
Description
Part/Model No.
Visibility Calibrator
M104744
2 pieces of opaque black foam
Psychrometer*
Psychrometric Calculator*
Digital Temp/RH Sensor*
Specifications
n/a
Model 5211 (Sling),
Model 5230 (Assmann)
or equivalent
Model 5282-A or
equivalent
Rotronics HC2-S3 or
equivalent
Z003919 or equivalent
Opaque black foam 1” to
4” inches thick.,
approximately 4” x 6”
±0.67° F (±0.37° C)
°F
±0.67 °F (±0.37 °C), 1%
RH
±0.0067 in Hg (±0.02%)
Reference Pressure Sensor
* Use either psychrometer & psychrometric calculator or Digital Temp/RH sensor.
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3.2 Triannual Maintenance Tools and Supplies
The following list gives the tools and supplies required during triannual maintenance of the
AWOS. This is in addition to that required for monthly procedures.
Description
Part/Model No.
Specifications
n/a
n/a
50', 16-3 or larger
4-1/2 digit
Basic scientific calculator capable
of performing square-roots and
exponent math – FX260, FX300ES, EL-501, HP-10S, HP-11C,
HP-15C, HP-32S, HP-35, TI-30,
and TI-84 are all popular models
Extension Cord
Digital Voltmeter
Scientific Calculator
Hewlett Packard
HP-35, Texas
Instruments TI30 or equivalent
8339 Ceilometer Desiccant
M028181-00
3.3 Perform Monthly Procedures
As part of triannual maintenance, perform the monthly maintenance procedures detailed in the
previous chapter. Only those procedures unique to triannual maintenance are provided in this
chapter.
3.4 Specific Triannual Maintenance
Constant vibration over time at certain sites such as oil platform sites may loosen the screws and
bolts used to secure the sensors and controller boxes to mounting struts or poles. Check these
screws and bolts as part of the triannual maintenance if the weather station is located at such a
high-vibration location, and retighten them as necessary.
3.4.1 Model 1190 Data Collection Platform
1. Press the maintenance switch (SW3).
2. On the DCP display, navigate to the analog-to-digital reference voltage screen (“ADC
Vref-” and “ADC Vref+”).

Verify that ADC Vref- is in the range 0–5.

Verify that ADC Vref+ is in the range 4090–4095.
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3.4.2 Model 7190 Dual Digital Barometer
The Model 7190 barometer is located in the top-right corner of the DCP.
1. Remove the quad plate pressure port drain plug (the Phillips screw on the underside of
the bottom plate) using a Phillips screwdriver, and drain any accumulated moisture.
2. Remove both flexible tubes from the barometer inlets and blow gently into the tubes to
clear any accumulated debris.
3. Replace the tubes and drain plug.
When performing the pressure check below, the reference pressure sensor (Z002919 or equivalent) should be lifted up until it is at the same level as the 7190. If the wind is blowing, the
reference sensor may deliver different readings, depending on which way it is facing and where
it is located. The quad-plate pressure port on the bottom of the DCP enclosure minimizes the
effect of wind on the 7190 pressure reading. If the reference sensor does not have a similar wind
compensation port, you may not be able to get accurate readings on windy days.
4. Compare the output of the reference sensor to that of the 7190. The value of the sensors
in the 7190 may differ from one another by up to 0.02 in Hg and still be within tolerance.
Sensors used in AWOS systems must be adjusted, as necessary, to within ±0.005 in Hg of
the reference sensor. Adjustments of more than 0.05 in Hg are not allowed. If either of
the sensors in the 7190 differs from the reference sensor by more than 0.05 in Hg, replace
the sensor.
5. Note the amount of deviation of each of the sensors in the 7190 from the reference; these
will be used as the adjustment values.
6. At the CDP, insert the CD Key into the optical drive. Go to the Edit > Configuration
menu, then to the Airport > General tab.
7. Enter the adjustment values in the BP Offset field. An offset will be “negative” if the
sensor reading is greater than the reference pressure standard.
8. Remove the CD Key from the optical drive at the CDP.
3.4.3 Model 2020 Wind Direction Sensor
No additional procedures.
3.4.4 Model 2030 Wind Speed Sensor
No additional procedures.
3.4.5 Model 2040 Ultrasonic Wind Sensor
No additional procedures.
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3.4.6 Model 5190 Temperature/Relative Humidity Sensor
Triannual maintenance of the Model 5190 Temperature/Relative Humidity Sensor consists of
performing the monthly maintenance tasks, cleaning the dust filter, and checking the accuracy of
the 5190 against readings made using a reference sensor or psychrometer, as explained below.
While performing the accuracy check, keep these provisions in mind.

For both temperature and dew point, it is important that the reference sensor be subject to
the same conditions as the Model 5190. If the reference sensor is in the sun, near your
body, or downwind from you, it is greatly affected. This will result in the reference
sensor and the 5190 delivering very different results. Even if the reference sensor is
removed from direct sun, reflected light (from snow or sand, for example) can affect the
measurements.

On cloudy, breezy days, there is usually no problem getting good reference readings. You
only need to be sure to stay downwind of the MARS and the reference sensor.

On sunny or calm days, it is often necessary to place the sensing element of the reference
sensor inside the MARS intake. This ensures that both sensors are sampling the same air
conditions. The reference sensor can be held in place in the MARS intake using a bungee
cord, wire, string, or tape. The reference sensor should not touch the sides of the MARS
tube or the 5190. The reference sensor must not block the MARS airflow.

The reference sensor can take up to ten minutes to stabilize, as the sensor body may have
absorbed or lost heat from contact with your body or from storage conditions. As you
observe the readings, the two sensors may start out several degrees apart, but will slowly
approach each other. Do not take any official reading until after the temperatures have
settled.

Differences in response time between the two sensors can also make field temperature
comparisons difficult. As wind changes direction, it can change humidity and
temperature. One sensor will always react faster than the other. Taking measurements in
changing conditions is not recommended.

Use of a sling psychrometer as a field reference sensor is strongly discouraged for anyone
except an experienced meteorologist. Electronic temperature/relative humidity sensors
and motor aspirated sensors are recommended for field use.
Triannual Model 5190 Temperature/Relative Humidity Sensor Procedures
1. Position the reference sensor as described above. Allow a minimum of 20 minutes for the
sensor to stabilize before proceeding.
2. Record the temperature and dew point temperatures from both the reference sensor and
the AWOS at 1 minute intervals for 5 minutes (5 readings).
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3. Compare the reference sensor temperature reading to the AWOS reading in each set. At
least three sets must have readings within ±1°F (±0.56° C) of one another. If fewer than
three sets are within this range, take a second round of readings (5 readings at 1-minute
intervals). If this second round fails to yield at least three sets of readings within ±1°F
(±0.56° C) of one another, the sensor must be replaced.
4. For each set of readings meeting the above requirement, subtract to find the difference
between the two temperatures and square the result.
5. Take the average of the square root of the average of the squared results obtained in the
previous step. If the result is within ±2°F (±1.1° C), the sensor passes. Otherwise, the
sensor must be replaced.
6. Compare the reference sensor dew point reading to the AWOS reading in each set. At
least three sets must have readings within ±0.5°F (±0.28°C) of one another. If fewer than
three sets are within this range, take a second round of readings (5 readings at 1-minute
intervals). If this second round fails to yield at least three sets of readings within ±0.5°F
(±0.28°C) of one another, the sensor must be replaced.
7. For each set of readings meeting the above requirement, subtract to find the difference
between the two dew point values and square the result.
8. Take the average of the square root of the average of the squared results obtained in the
previous step. If the result is within ±3°F (±1.7° C), the sensor passes. Otherwise, the
sensor must be replaced.
3.4.7 Model 8190 MARS
1. Remove the MARS fan fuse (F1) at the DCP and verify that the DCP indicates a fan
failure.
2. Replace fuse F1.
3.4.8 Model 6011 Rain Gauge
No additional procedures.
3.4.9 Model 6021 Heated Rain and Snow Gauge
No additional procedures.
3.4.10 Model 8364-E Visibility Sensor
The Visibility Sensor is calibrated during triannual maintenance. This must be performed when
there is at least 7 miles visibility with calm wind conditions. The calibration paddle is traceable
to Air Force Geophysics Laboratory reference transmissometers. Equivalent extinction
coefficient values are printed on each paddle.
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1. If the sun is shining directly or is being reflected into the emitters or detectors, note the
original orientation of the Visibility Sensor, then loosen the crossmember mounting bolt
and rotate the entire head assembly so that no direct or reflected sun shines into the
emitters or detectors.
2. Press the # key on the DCP keypad repeatedly until the 8364-E calibration screen
appears.
Note: If more than a few minutes have elapsed since the maintenance switch was
originally pressed, it may be necessary to press it again to enable access to the visibility
calibration screens.
Cal 8364E Vis Sensor
1 to Cont or # to Exit
Figure 2. Visibility Calibration Screen
3. Enter the Cal I.D. # shown on the calibration paddle label.
4. A routine will be executed by the visibility controller to ensure proper operation prior to
calibration measurements. You will be prompted to perform routine maintenance, such as
removal of obstructions in the optical paths and cleaning of the sensor windows, during
this routine. While you are performing the requested maintenance, the sensor will operate
alternately in both modes to keep the optical emitters at thermal equilibrium. When you
press a key to continue, as prompted, the controller may take up to one minute to
respond. The sensor will then begin its calibration measurements.
5. The initial measurement takes five minutes. When the five minute interval is complete,
you will be prompted to insert the calibration paddle.
6. Insert the calibration paddle. Hit the # key to continue.
7. After a second five minute measurement interval, you will be prompted to remove the
calibration paddle and block the emitters (“COVER EMS”).
8. Remove the calibration paddle at this point and insert a piece of black foam over each
emitter opening so that no emitted radiation will reach the detectors. Press the # key to
continue.
Note: If the emitters cannot be completely covered, the calibration procedure will not be
able to reliably get within the required 3% accuracy. If this happens, the emitters may be
disconnected at the controller instead of being covered. The emitters should be left
disconnected until after the test is complete, at which time the Visibility Sensor should be
turned off, the emitters reconnected, and the Visibility Sensor turned back on. It is safe to
disconnect the emitters with power applied.
9. Following a further set of measurements, a new set of calibration coefficients are
generated for the sensor. The new coefficients are stored in a protected EEPROM. This
calibration method requires no fine adjustment of analog circuitry, nor opening of the
emitter or detector heads.
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10. Upon completion of the measurement cycle, the display will show the old and new
calibration values. You will be given the option to accept or reject the new value. Press
the # key to accept it. The value should only be rejected if the technician believes the
value is bad due to a problem during calibration (the foam block falls from the emitter,
for example).
11. If the difference between the old and new values is more than 3%, you must repeat the
calibration process until the difference is less than 3%. In normal operation, when the
sensor is calibrated on a regular basis (every 3–4 months), the calibration difference will
rarely exceed 3%. If a long period has elapsed since the last calibration, the difference
may exceed 3%. This is normal.
12. Record the old and new calibration values in an ongoing log for future reference.
13. Once the calibration value has been accepted, the visibility controller will return to
normal measurement mode using the newly calculated calibration values.
14. If the calibration procedure is not followed correctly or there is a fault with the sensor,
the calibration process will abort and the Visibility Sensor will return to normal
operation. If this should happen, follow the troubleshooting procedures in the Model
8364-E User’s Manual should be followed to isolate the problem.
15. Once the Visibility Sensor has been operating for 10 minutes, verify there are no
improper status errors reported at the DCP.
16. Verify that the entire head assembly and crossarm are back to the original position noted
in Step 1, and then tighten the crossmember mounting bolt in the base of the
crossmember so that it does not rotate.
If a Day/Night sensor is installed, check its operation as follows.
1. During daytime, set the DCP’s LCD display to show Day/Night status.
2. Verify that the display shows the sensor is reading “day.”
3. Cover the lens with a black bag. Within 3–5 minutes, the output should switch to the
“night” state.
4. Uncover the lens, and verify that the output switches back to the “day” state.
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3.4.11 Model 8339 Ceilometer
1. Clear the Heater/Blower air intake and output nozzle of any impediments, such as spider
webs, leaves, or other matter.
2. Check the status LEDs visible from outside the Ceilometer through the transmitter
window.

The red System Status LED alternates between on and fast blinking when the
Ceilometer is operating normally.

The green Battery Status LED is on when the DC power (battery) is good.

The yellow Dirty Window LED is off when the window is clean.
3. Replace the desiccant package at each triannual maintenance visit. If the enclosure door is
opened during maintenance or service at any time, replace the desiccant package (M028179-00)
before closing the door for the final time. To preserve the desiccant material, the package
is sealed within a plastic bag during shipment. Remove and discard the plastic bag.
3.4.12 Model 6490 Present Weather Sensor
1. Check the strength of the carrier signal by displaying the present weather status screen on
the DCP display (press the * or # keys until the screen below is displayed).
XnnnLnnnKnnnHnnnTnnn
2. The carrier raw data field (Xnnn) should be in the range of 405–420. If it needs to be
adjusted, refer to the Model 6490 User’s Manual.
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The remaining tests should be performed when there is no precipitation and after the sensor has
stabilized for at least 30 minutes.
3. The following values should be observed on the status screen.

Lnnn - The one-minute low channel reading should read in the range of -30 to 50.

Knnn - The one-minute particle channel reading should read in the range of 0 to 150.

Hnnn - The one-minute high channel reading should read in the range of 40 to 120.

Tnnn - Temperature should be representative of the ambient temperature, with a
tolerance of ±5°C. The temperature probe is thermally connected to the electronics
enclosure, so it generally reads warmer than the ambient temperature because of
internal heating of the enclosure.
If any of the values is outside the allowed range, report the problem.
4. Display the present weather data screen on the DCP display using the * and # keys.

The present weather field (W___) should not contain any data (two underscores) if
there is no precipitation falling. As long as there is no precipitation falling and the
present weather field displays anything other than two underscores, report the problem.

The status fields should all read zeros (S0000) if the sensor has been operating (and
not reset by a power interruption) for at least 5 minutes. If the status fields are not all
zeros, refer to the Model 6490 User’s Manual for an interpretation of the possible
problem.
3.4.13 Model 6500 Thunderstorm/Lightning Sensor
1. Check the sealant around the antenna base and mounting bolts, and reapply as necessary
(use RTV 162).
2. Check all hardware for corrosion and ensure that all bolts and connectors are tight.
3. Ensure that the cable connections are sound between the sensor and DCP.
3.4.14 Model 6495 Freezing Rain Sensor
No additional procedures.
3.4.15 Central Data Processor (CDP)
No additional procedures.
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4
R E V A L I D A T I O N
Chapter
Annual System Revalidation
Annual system revalidation is carried out yearly. These procedures are also required at commissioning and after major repair work— replacement of a sensor or any part of a sensor, or
adjustment of any part of the sensor circuit (e.g., adjusting the carrier level on the present
weather sensor). Follow the procedures below, take any required corrective action, and record
the results on the Annual Technical Performance Record.
Only an FAA authorized technician of record for the site may perform the annual system
revalidation procedures.
4.1 Annual Revalidation Test Equipment
The following list gives the test equipment required during annual revalidation of the AWOS.
This is in addition to that required for monthly and triannual procedures.
Description
Part/Model No.
Wind Direction Calibrator
Wind Speed Calibrator
Model 1249-A
Model 1231
Integrity Check Chamber
M105548-00
Specifications
For Model 2020 vane
for Model 2030 anemometer
for 2040 Ultrasonic Wind
Sensor
Radio Test Equipment:
Power Meter
Forward/Reflected Power
Tester
Frequency Meter
Modulation Meter
Deviation Meter
Bird Watt Meter Model 43 or equivalent
Bird Watt Meter Model 43 w/ 10C (VHF) and 5D (UHF)
elements or equivalent
Aeroflex 3500 or equivalent
Aeroflex 3500 or equivalent
Aeroflex 3500 or equivalent
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4.2 Annual Revalidation Tools and Supplies
The following list gives the tools and supplies required during annual revalidation of the AWOS.
This is in addition to that required for monthly and triannual procedures.
Description
Allen Wrench
Scientific Calculator or
Software
Non-corrosive Lubricant
Corrosion Protection
Coating
Part/Model No.
Specifications
n/a
1/16”
Hewlett Packard HP-35,
Basic scientific calculator or
Texas Instruments TI-30
software capable of performing
or equivalent; Microsoft
square-roots and exponent
Calculator, Excel or
math
equivalent
Loctite Silver Grade anti-seize compound or equivalent
M402010-00 corrosion block spray or equivalent
4.3 Perform Monthly and Triannual Procedures
As part of annual maintenance, perform the monthly and triannual maintenance procedures
detailed in the previous chapters. Only those procedures unique to annual maintenance are
provided in this chapter.
4.4 Specific Annual Maintenance
4.4.1 Model 1190 Data Collection Platform
1. Press the maintenance switch (SW3).
4.4.2 Model 7190 Dual Digital Barometer
1. Using the barometric pressure value obtained with the reference pressure sensor during
triannual maintenance, calculate the Altimeter Setting using the formula below:

Alt. Setting (in Hg )  BP   SE 1.313  10 5

5.25486
where :
  0.1903
SE  Sensor elevation above sea level in feet
BP  Barometric pressure in in Hg
2. Record the calculated altimeter setting and that reported by the AWOS.
3. If the difference between the calculated altimeter setting and that reported by the AWOS
is more than 0.01 in Hg, please advise AWI Customer Service at 1(916)928-1000.
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4.4.3 Model 2020 Wind Direction Sensor
1. Remove the sensor from the mounting bracket by loosening the clamp screw located at
the base of the unit. Leave the sensor cable and, if present, the heater cable connected.
These cables will ensure that, if the sensor is dropped, the device will not fall.
2. Clean the drain hole on the bottom of the sensor to ensure that debris does not prevent
water from draining out of the sensor.
3. Spread non-corrosive lubricant on the clamp screw and reinstall the sensor. The sensor
mounting hole should be aligned with the pin on the base of the mounting bracket.
4.4.3.1 Alignment
The Model 1249-A Wind Direction Calibrator is required when aligning the sensor on both the
stationary or foldover tower types.
1. Locate the direction benchmark determined in the initial site survey. It should be
approximately 100 to 150 feet from the tower in one of the four cardinal points
referenced to true north. Align the sensor using the procedure below for either the
stationary or foldover tower. When the sensor is installed on a foldover tower, it will be
necessary to raise and lower the tower several times during alignment.
2. Separate the two halves of the Model 1249-A Wind Direction Calibrator by pulling the
two discs apart.
3. Slip the bottom half of the calibrator (containing the knurled knob) onto the stationary
portion of the vane's housing near the rotating cap. Loosen the knob, if necessary, to do
this; then tighten the knob until the unit is secured.
4. Hold the vane’s tail shaft and place the top half of the calibrator onto the shaft and sensor
cap. Notice that the top half is recessed to accommodate the counter weight, and that
there is a groove for the tail shaft and a cutout for the top of the vane cap.
5. Rotate the top plate until the four pins are aligned with the holes in the bottom plate. The
bottom half of the calibrator may require adjusting if it is too high or too low on the vane
housing. Loosen the knurled knob and position the bottom half as needed.
Note that the next steps for aligning a sensor require two people when the sensor is on a
stationary tower—one person on the ground to observe the DCP’s LCD display, and the
other on the tower.
6. While observing the LCD display inside the DCP, loosen the knurled knob slightly and
rotate the entire calibration unit (along with the sensor tail) until the DCP indicates 180°.
(If the benchmark is located at East or West, rather than North or South, rotate the vane
until the display reads 90 or 270.) Securely tighten the knurled knob to hold the vane in
this position.
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7. With the sensor locked in position, stand at the direction benchmark and verify that the
tail of the vane is aligned with the vane body. If the vane is not aligned, loosen the
mounting screw located at the bottom of the Unistrut, align the sensor (and base) with the
benchmark, and tighten the mounting bolt.
8. Lift the top half of the calibrator and rotate it and the vane tail 90° to the next position.
Verify that the DCP display agrees with the new direction. Continue rotating the sensor
to each of the remaining cardinal directions and verify that the vane position and DCP
display agree.
If the DCP display does not match the vane position, replace the Model 2020 Wind
Direction Sensor.
9. Remove the calibrator.
10. Rotate the vane slowly through a full 360°, noting the reading on the LCD display (if on
a foldover tower, the tower can be in the lowered position during this procedure). As the
vane is turned, the displayed values should change smoothly, with no sudden jumps or
dropouts. Note, however, that there is a 10° deadband at North where the DCP reading
shows a steady value of 359°–001° in the 355°–005° deadband. This behavior is normal
near North, but in any other direction indicates a potentiometer failure. If the sensor fails
any part of this test, report the problem.
11. Verify that the vane’s movement is free and smooth. If it is not, replace the bearings. The
shaft should turn freely at all times.
12. Inspect all mounting hardware and cable assemblies for wear and damage. Replace as
necessary.
13. Apply corrosion protection coating to the connector shell after the connector is attached
and in place. Use a non-corrosive lubricant on all screws and fasteners whenever
disassembly is required. The use of these lubricants will make future servicing easier.
14. If heaters are installed, verify they are working by holding your hand close to the heater.
The heater is always on, and should be warm.
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4.4.4 Model 2030 Wind Speed Sensor
1. Remove the anemometer cup assembly by loosening the two set screws on the cup
assembly collar using a 1/16" Allen wrench.
2. Connect a Model 1231 run-up motor to the anemometer shaft and power the motor on.
The DCP display should read between 79 and 81 knots.
3. Spin the shaft as fast as you can, using your thumb and middle finger. If the bearings are
good, the shaft will spin for a minimum of 30 seconds. If the bearings feel rough or fail to
spin for the 30-seconds, replace the bearings as described in the Model 2030 Sensor
User’s Manual.
4. Replace the cup assembly.
5. Inspect the anemometer cups for damage, and replace if necessary.
6. Remove the sensor from the mounting bracket by loosening the clamp screw located at
the base of the unit. Leave the sensor cable and, if present, the heater cable connected.
These cables will ensure that, if the sensor is dropped, the device will not fall.
7. Clean the drain hole on the bottom of the sensor to ensure that debris does not prevent
water from draining out of the sensor.
8. Use an anti-seize thread compound on the clamp screw and reinstall the sensor. The
sensor mounting hole should be aligned with the pin on the base of the mounting bracket.
9. Inspect all mounting hardware and cable assemblies for wear and damage. Replace as
necessary.
10. Apply corrosion protection coating to the connector shell with the connector attached and
in place. Use a non-corrosive lubricant such as bee wax on all screws and fasteners. The
use of these lubricants will make future servicing easier.
11. If heaters are installed, verify they are working by holding your hand close to the heater.
The heater is always on, and should be warm.
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4.4.5 Model 2040 Ultrasonic Wind Sensor
During annual maintenance, perform a Field Zero Wind Check as described below.
1. Install the Integrity Check Chamber (ICC) by inserting the reflector cases and the two
halves of the ICC onto the Model 2040. The ICC must be retained using the strips
provided.
2. View the wind speed value displayed at the DCP. The value must not exceed 0 knots. If
the wind speed exceeds 0 knots, report the problem.
3. The sensor’s alignment mark (the blue/white divide on the serial number label) must be
aligned with the direction benchmark. Visually check the sensor’s alignment by either

sighting along the sensor arms from the tower and verifying that the arms align with
the benchmark, or

have an assistant stand at the marker and check that the arms align with the
benchmark.
4. If the alignment needs to be adjusted, loosen the sensor mount and turn the entire sensor
until the arms are aligned exactly with the benchmark, then tighten the mount.
4.4.6 Model 5190 Temperature/Relative Humidity Sensor
No additional procedures.
4.4.7 Model 8190 MARS
No additional procedures.
4.4.8 Model 6021 Heated Rain and Snow Gauge
1. Place your hand close to the outlet orifices to detect whether heat is emanating from the
two orifice heaters. If the outlets are warm, then the heater system is powered up.
2. Remove the outer cover by removing two 1/4" bolts. Unplug the 3-conductor Molex
connector (P1) from the power distribution housing (J1) in order to completely separate
the outer cover from the base.
3. Check the sensor level using the bubble level provided on the base. Adjust if necessary.
4. Inspect the interior of the gauge for physical lightning damage.
5. Remove any dirt or debris that may be present inside the sensor.
6. Note the precipitation quantity on the DCP's LCD display. Toggle the bucket assembly
one cycle (2 tips). Again read the precipitation quantity on the LCD display. It must be 2
counts greater than before.
If this count incrementation does not happen as described, examine the tipping bucket
assembly, the counter, and the sensor cable connections between the sensor and the DCP.
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7. Plug the 3-conductor Molex connector (P1) into the power distribution housing (J1).
Replace the outer cover and bolts, coating the bolts with anti-seize compound. Replace
the screen.
4.4.9 Model 8364-E Visibility Sensor
No additional procedures.
4.4.10 Model 8339 Ceilometer
No additional procedures.
4.4.11 Model 6490 Present Weather Sensor
No additional procedures.
4.4.12 Model 6500 Thunderstorm/Lightning Sensor
No additional procedures.
4.4.13 Model 6495 Freezing Rain Sensor
No additional procedures.
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4.4.14 Radio Annual Revalidation
When VHF antenna cables are longer than 50 feet, tests must be repeated at the antenna end of
the cable. UHF radio tests at the radio end are sufficient regardless of the length of the antenna
cable.
4.4.14.1 Model 1792 Ground-to-Air VHF Radio
Power Level
1. Remove AC power from the radio by turning the power switch on the radio’s front panel
off.
2. Connect the power meter to the connector on the radio and terminate with the antenna or
a dummy load.
3. Indicate the VHF radio output power level on the Annual Technical Performance Record.
VSWR (at transmitter)
If RF cables must be disconnected when switching between power level and VSWR tests, turn the
radio off using the switch on the radio’s front panel.
1. Insert a VSWR or forward/reflected power tester.
2. Measure the VSWR and enter the value on the Annual Technical Performance Record. If
you measure forward and reflected power, calculate the VSWR using the following
equation.
reflected power
forward power
VSWR 
reflected power
1
forward power
1
Sample Calculation:
Reflected power = 0.02 W
Forward power = 2.5 W
reflected _ power
forward _ power
0.02
1  0.008 1  0.0894 1.0894
2.5
VSWR 




 1.1964
reflected _ power
0.02 1  0.008 1  0.0894 0.9106
1
1
forward _ power
2.5
1
1
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Frequency
CAUTION
Use isolators or attenuators as needed to protect the test equipment.
If RF cables must be disconnected when switching between frequency and modulation tests, turn
the radio off using the switch on the radio’s front panel.
1. Log the assigned frequency on the Annual Technical Performance Record.
2. Insert a frequency meter.
3. The radio transmits for approximately 30 seconds, followed by an off time of five
seconds. While the radio is transmitting, measure the frequency.
4. Record the frequency on the Annual Technical Performance Record.
Modulation
CAUTION
Use isolators or attenuators as needed to protect the test equipment.
If RF cables must be disconnected when switching between frequency and modulation tests, turn
the radio off using the switch on the radio’s front panel.
1. Log in as an administrator on the CDP display and insert a AWOS Security Key CD. You
will be able to access the menus once the optical drive light stops blinking, indicating that
the AWOS Security Key CD has been read.
2. Connect a modulation meter to the VHF radio. Set the modulation meter to the
instantaneous mode.
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3. Access the Edit > Configuration > Voice tab on the CDP display and click the 300 Hz
tone option in the Test panel.
4. Use the modulation adjustment potentiometer on the VHF radio to adjust the modulation
depth to 90%.
Modulation Adjustment Pot
Figure 3. VHF Radio Modulation Adjustment Potentiometer
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5. Use the VHF adjustment potentiometer on the CDP peripheral interface board to lower
the signal level until the modulation decreases to 80%.
Figure 4. VHF Adjustment Potentiometer on CDP Peripheral Interface Board
6. Use the modulation adjustment potentiometer on the VHF radio to adjust the modulation
depth to 60%.
7. Set the modulation meter to the “peak hold” mode.
8. Access the Edit > Configuration > Voice tab on the CDP display and click the
Modulated 300 Hz tone option in the Test panel.
9. Reset the modulation meter and wait until the modulated tone stops.
10. Verify that the peak modulation reading does not exceed 95%. If it does, adjust the modulation adjustment potentiometer on the VHF radio and recheck the peak modulation reading.
11. Access the Edit > Configuration > Voice tab on the CDP display and click the Word
option in the Test panel.
12. Reset the modulation meter and wait until the words stop. Verify that the peak modulation
reading does not exceed 95%. If it does, adjust the modulation adjustment potentiometer
on the VHF radio and recheck the peak modulation reading.
13. Enter the final modulation meter reading on the Annual Technical Performance Record.
14. Turn the radio off using the front panel switch. Disconnect the test equipment and cables,
and reconnect the antenna. Turn the radio on.
15. Remove the CD Key from the CDP optical drive.
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4.4.14.2 Model 20980-A UHF Data Link Radio
Perform the following procedures on both the DCP and CDP UHF radios.
Power Level
1. Remove power from the UHF radio by disconnecting the DB9 connector.
2. Connect a power meter to the radio connector and terminate with the antenna or a dummy
load.
3. Reconnect the DB9 connector to restore power to the UHF radio.
4. Measure the forward power on the power meter and record on the Annual Technical
Performance Record.
VSWR (at transmitter)
If RF cables must be disconnected when switching between power level and VSWR tests, remove
power from the radio by disconnecting the DB9 connector.
1. Insert a VSWR or forward/reflected power tester.
2. Measure the VSWR and enter the value on the Annual Technical Performance Record. If
you measure forward and reflected power, calculate the VSWR using the following
equation.
reflected
forward
VSWR 
reflected
1
forward
1
power
power
power
power
Sample Calculation:
Reflected power = 0.02 W
Forward power = 1 W
reflected _ power
forward _ power
0.02
1  1  0.02  1  0.1414  1.1414  1.3293
VSWR 

reflected _ power
0.02 1  0.02 1  0.1414 0.8586
1
1
forward _ power
1
1
1
35
A N N U A L
S Y S T E M
R E V A L I D A T I O N
AWOS 3000 MAINTENANCE
Frequency
CAUTION
Use isolators or attenuators as needed to protect the test equipment.
If RF cables must be disconnected when switching between VSWR and frequency tests, remove
power from the radio by disconnecting the DB9 connector.
1. Log the assigned frequency on the Annual Technical Performance Record.
2. Insert a frequency meter.
3. Measure and log the frequency on the Annual Technical Performance Record.
Deviation
CAUTION
Use isolators or attenuators as needed to protect the test equipment.
If RF cables must be disconnected when switching between VSWR and frequency tests, remove
power from the radio by disconnecting the DB9 connector.
1. Insert a deviation meter.
2. Enter the meter reading on the Annual Technical Performance Record.
3. Remove AC power from the radio, disconnect the test equipment and cables, reconnect
the antenna, and restore AC power.
4.4.15 Central Data Processor (CDP)
1. Verify that no active alarms are present.
2. If active alarms are present, delete the alarms (after performing all annual procedures)
and verify that the alarms do not recur. If alarms persist, report the problem to the Airport
Manager.
36
T R O U B L E S H O O T I N G
5
G U I D E
Chapter
Troubleshooting Guide
The following pages provide troubleshooting steps for the various AWOS 3000 sensors and
major system components.
37
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.1 Central Data Processor (CDP)
Is CDP
weather
display
running?
Is CDP clock
incrementing?
Is UPS running
(UPS lights and
fan are on)?
Is data from an
individual
sensor missing
or incorrect?
Examine link
from that
sensor to DCP
Are all CDP
display sensor
data missing or
incorrect?
Is data display
on DCP screen
OK?
Check DCP/
CDP UHF radio
or RS-485 link
Contact AWI
Customer Service
+1 (916)928-1000
Is there 12–16 V DC
on DCP TB1 pins
5(+) and 6(–)?
Replace DCP
(P/N 2090)
Is there 110–120 V AC
at the AC interface
board TB2 (output)
pins 1 and 2?
Replace DCP
power supply
(P/N M438210-00)
Is there 110–120 V AC
at the AC interface
board TB1 (input) pins
1 and 2?
Check AC
interface board
fuses and on/off
switch
Check AC
power wiring
and breakers
Is UPS running
(lights on, rack
fan running)?
Reload
software
Replace CPU
assembly (P/N
M406186-00)
CPU fan is not
running
Are there lights on
the interface board,
modem, and radio or
RS-485 adapter?
Cycle UPS
power off/on
Replace CPU
assembly (P/N
M406186-00)
No DC power
Replace CPU
assembly (P/N
M406186-00)
Contact AWI
Customer Service
+1 (916)928-1000
UPS not
running
Disconnect UPS
batteries. Does
UPS run without
batteries?
Replace UPS
(P/N 20913-F)
38
Replace UPS batteries
(12 V, 7.2 A·h)
(Minuteman P/N
37000007)
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.2 Temperature/Relative Humidity/Barometric Pressure
Sensors
Are displayed
temperature
data bad?
Are displayed
relative humidity
data bad?
Are displayed
pressure data
bad?
Is the voltage at DCP TB2-1
(referenced to TB2-4) consistent with
the displayed value if calculated from
°C = 100 × volts – 40 (volts = 0 – 1 V)
Replace the 5190
temperature/RH
probe
Contact AWI
Customer Service
+1 (916)928-1000
Is the voltage at DCP TP11
(referenced to TB2-4) consistent with
the displayed value if calculated from
°C = 100 × volts – 40 (volts = 0 – 1 V)
Replace the DCP
main PC board
(P/N M404804 )
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
main computer
daughter board
(P/N M487094)
Contact AWI
Customer Service
+1 (916)928-1000
Is the voltage at DCP TB2-1
(referenced to TB2-4) consistent with
the displayed value if calculated from
RH = volts × 100
Replace the 5190
temperature/RH
probe
Contact AWI
Customer Service
+1 (916)928-1000
Is the voltage at DCP TP3
(referenced to TB2-4) consistent with
the displayed value if calculated from
RH = volts × 100
Replace the DCP
main PC board
(P/N M404804 )
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
main computer
daughter board
(P/N M487094)
Contact AWI
Customer Service
+1 (916)928-1000
Are pressure data
displayed at all?
Disconnect DCP TB4 and
remove all 11905 (P/N
M404806) interface cards
Is pressure data
displayed > 0.05 inHg
different from the
reference sensor?
Replace the 7190
pressure sensor
Reconnect one interface card at a
time to determine which one causes
the problem — repair or replace the
problem interface card
Replace the 7190
pressure sensor
39
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Are wind
speed data
bad?
Set the DCP SW2 switch
settings per the 1190 DCP
User’s Manual
Does the DCP
display identify
the wind sensor
model correctly?
Is the wind sensor
the Model 2030
Anemometer?
Are wind
speed data
missing?
Is there 10–16 V
DC on the wind
speed sensor
red/black wires?
Check and replace wind
speed sensor bearings per the
2030 User’s Manual
40
Replace the DCP
main PC board
(P/N M404804 )
Replace the DCP
main computer
daughter board
(P/N M487094)
Contact AWI
Customer Service
+1 (916)928-1000
Check the 2030 wind
sensor and the
associated cables for
opens and shorts
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the 11905-G
wind speed interface
board
Reprogram the
wind sensor per
the 2040 User’s
Manual
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
main PC board
(P/N M404804 )
With DCP TB2 unplugged, is
there 10–16 V DC at TB2-5
(referenced to TB2-8)?
Replace the DCP
main PC board
(P/N M404804 )
Is there 1–2 V variablefrequency AC at DCP TP4
(referenced to TB2-7) when
the wind blows?
Contact AWI
Customer Service
+1 (916)928-1000
With DCP TB2 unplugged, is
there 4–6 V DC at
TB2-6 (referenced to TB2-7)?
Is there more than 0.5 V
variable-frequency AC at DCP
TB2-6 (referenced to TB2-7)
when the wind blows?
Replace the RS-232/
RS-422 converter
Contact AWI
Customer Service
+1 (916)928-1000
Disconnect the DB-9 connector from the wind speed
RS-232/RS-422 converter and connect a laptop to the
converter. Using a terminal emulator set to 9600-8-N-1,
do you see text/numeric data once per second?
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the 2040 wind
speed sensor
Are there 0.5–2.0 V AC
pulses once per second
on the wind speed sensor
green/black wires?
Replace the 2040 wind
speed sensor
Repair DC power wiring
to sensor
Does the wind speed
sensor pass the annual
zero- wind speed test?
Contact AWI
Customer Service
+1 (916)928-1000
Is the wind sensor
the Model 2040
Ultrasonic Wind
Sensor?
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.3 Wind Speed Sensors
Are wind
direction data
bad?
Is the wind sensor
physically aligned to
True North?
Contact AWI
Customer Service
+1 (916)928-1000
Align the wind direction
sensor per the procedure
in the User’s Manual
Set the DCP SW2 switch
settings per the 1190 DCP
User’s Manual
Does the DCP
display identify
the wind sensor
model correctly?
Contact AWI
Customer Service
+1 (916)928-1000
Is the wind sensor
the Model 2020
Vane?
Is the wind sensor
the Model 2040
Ultrasonic Wind
Sensor?
With DCP TB3 disconnected,
is there ~2.5 V DC at TP3-1?
Is there 1.5–2.0 V DC
at DCP TP3-1?
Contact AWI
Customer Service
+1 (916)928-1000
Check wind direction sensor
electrical alignment and
bearings per the 2020
User’s Manual
Reprogram the
wind sensor per
the 2040 User’s
Manual
41
Replace the DCP
main PC board
(P/N M404804 )
Check the 2020 vane
and the associated
cables for opens and
shorts
With DCP TB3 disconnected,
check the resistance between
TB2-2(+) and TB2-3(-)
Is it 900 k – 1.1 M ?
Is there a varying DC voltage
in the range of 0–1.7 V at
DCP TP3-2 as the wind
direction changes?
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
main PC board
(P/N M404804 )
Check the 2020 vane
and the associated
cables for opens and
shorts
Replace the DCP
main PC board
(P/N M404804 )
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
main computer
daughter board
(P/N M487094)
Contact AWI
Customer Service
+1 (916)928-1000
Is there a varying DC voltage
in the range of 0–1.7 V at
DCP TP10 as the wind
direction changes?
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.4 Wind Direction Sensors
Are visibility
data bad?
Troubleshoot the visibility sensor per
the procedure in the "Troubleshooting"
section of the 8364-E User’s Manual.
Repair as appropriate.
Can the visibility sensor be
calibrated (and the new
calibration values
accepted)?
Contact AWI
Customer Service
+1 (916)928-1000
RS-485 communication
problem
Can the visibility sensor be
placed in and out of test
mode using the DCP?
Contact AWI
Customer Service
+1 (916)928-1000
42
Replace the
visibility controller
(P/N M404811 )
Contact AWI
Customer Service
+1 (916)928-1000
Remove the visibility wires from DCP
TB4-3 and TB4-4. Measure the
voltage on the wires. Reconnect the
wires. Was the voltage the exact same
as measured on the previous step?
Replace the wires running between
the DCP and the visibility controller
Contact AWI
Customer Service
+1 (916)928-1000
Remove the wires from the 8364-E
visibility controller TB2. Measure
the DC voltage between TB2-2(+)
and TB2-1(-). Reconnect the wires.
Was the voltage 0.2–1.0 V?
Remove the visibility controller "RS-485 LOAD"
jumper (and leave it off) and ensure the RS-485
wiring to the DCP is hooked up per the wiring
diagrams at the end of the 1190 DCP User’s Manual
RS-485
communication is OK
and the sensor is OK
Contact AWI
Customer Service
+1 (916)928-1000
Test and repair the continuity of the
reference wire and the connection of
ground and power line grounds for the
DCP and visibility controller
Remove the "reference" wire from
visibility controller TB2-7. Measure the AC
voltage between the end of the wire and
TB2-7. Reconnect the wire. Was the
voltage less than 2 V AC?
Contact AWI
Customer Service
+1 (916)928-1000
Replace the
visibility controller
(P/N M404811 )
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.5 Visibility Sensor
Are ceilometer
data bad?
Replace the ceilometer
power supply
(P/N M438200-00)
Check internal switch/
breaker CB1 and
whether external AC
power is present
Do the yellow/brown
wires on the ceilometer
power supply have
90–240 V AC?
Replace the ceilometer
DAQ PC board
(P/N M404848-02)
43
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the ceilometer
DAQ PC board
(P/N M404848-02)
Is the red LED (in the center of
the ceilometer and visible through
the left-side window) blinking in a
complex 30-second pattern?
Do the yellow/brown
wires on the ceilometer
power supply have
90–240 V AC?
Do the violet/yellow
wires on the ceilometer
power supply have
12–14 V DC?
Is the green LED (in the
center of the ceilometer and
visible through the left-side
window) on?
Is the ceilometer status
displayed at the DCP?
Replace the ceilometer
DAQ PC board
(P/N M404848-02)
Measure the voltage on the
ceilometer DAQ board J7-2.
Is it between -3 and -15 V?
Contact AWI
Customer Service
+1 (916)928-1000
Replace the ceilometer
communication cable
(P/N M491742-00)
Replace the DCP
ceilometer serial
interface board
(P/N M404806)
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the ceilometer
DAQ PC board
(P/N M404848-02)
Check the aim of the LED in
the dirty window and
reprogram the ceilometer
settings in the dirty window.
Decode ceilometer status codes displayed
on the DCP using the chart in the
"Troubleshooting" section of the 8364-E
User’s Manual. Replace indicated parts.
Clean the
ceilometer windows.
Does the yellow
LED remain on?
In the DCP, disconnect the white wire from ceilometer serial
interface board TB1-2. Using interface board TB1-3 as a
reference (with the black and shield wire still connected),
measure the DC voltage on the free white wire. Reconnect the
white wire. Was the voltage between -3 and -15 V?
Contact AWI
Customer Service
+1 (916)928-1000
Is the yellow LED (in the
center of the ceilometer
and visible through the
left-side window) on?
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.6 Ceilometer
Does the Present Weather
sensor send status codes
to the DCP display?
Are
Thunderstorm/
Lightning data
bad?
44
Replace the wires running
between the DCP and the
Thunderstorm/Lightning sensor
Contact AWI
Customer Service
+1 (916)928-1000
Test and repair the continuity of the reference wire and the
power line and ground connections for the DCP, Present
Weather controller, and Present Weather sensor
Remove the Present Weather "reference" wire from the
Present Weather interface card TB1-6 (red). Measure
the AC voltage between the end of the wire and TB2-7.
Reconnect the wire. Was the voltage less than 2 V AC?
Contact AWI
Customer Service
+1 (916)928-1000
Remove the Thunderstorm/Lightning sensor
"reference" wire from DCP Thunderstorm/
Lightning sensor interface card TB1-6 (red).
Measure the AC voltage between the end of
the wire and TB2-7. Reconnect the wire. Was
the voltage less than 2 V AC?
Contact AWI
Customer Service
+1 (916)928-1000
Replace the
Thunderstorm/
Lightning sensor
(P/N 6500)
Replace the wires running between
the DCP and the Present Weather
controller
Remove the Thunderstorm/Lightning
sensor wires from DCP TB4-1 (white)
and TB4-2 (black). Measure the
voltage on the wires. Reconnect the
wires. Was the voltage the exact same
as measured in the previous step?
Contact AWI
Customer Service
+1 (916)928-1000
Remove the wires from the DCP
Thunderstorm/Lightning interface card
TB1-4 (white) and TB1-5 (black).
Measure the DC voltage between
TB1-4(+) and TB1-5(-). Reconnect the
wires. Was the voltage 0.2–1 V?
Replace the Present
Weather controller and
associated sensor
(P/N 6490 & M404806)
Contact AWI
Customer Service
+1 (916)928-1000
Remove the Present Weather sesnsor wires from DCP
TB4-1 (white) and TB4-2 (black). Measure the voltage on
the wires. Reconnect the wires. Was the voltage exactly
the same as measured in the previous step (0.2–1 V)?
Review the status codes per the 6490
User’s Manual "AWOS Maintenance and
Troubleshooting" section, and adjust or
repair as needed
Remove the wires from the Present Weather
interface card TB1-4 (white) and TB1-5 (black).
Measure the DC voltage between TB1-4(+) and TB15(-). Reconnect the wires. Was the voltage 0.2–1 V?
Are Present
Weather data
bad?
Replace the
Thunderstorm/
Lightning sensor
(P/N 6500)
Contact AWI
Customer Service
+1 (916)928-1000
Replace the Present
Weather controller and
associated sensor
(P/N 6490 & M404806)
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.7 Present Weather and Thunderstorm/Lightning Sensors
Does the Freezing Rain sensor
send status information to the
DCP display?
In the Freezing Rain sensor, unplug J2.
Using the pin on the PC board the black wire
was connected to as a reference, measure
the voltage on the PC board pin the red wire
was connected to. Reconnect J2. Was the
voltage between -3 and -15 V?
Contact AWI
Customer Service
+1 (916)928-1000
45
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Replace the DCP
Freezing Rain sensor
communication cable
(P/N M491740)
Replace the DCP
Freezing Rain sensor
(P/N 6495)
Replace the DCP
Freezing Rain serial
interface board
(P/N M404806)
Replace the DCP
Freezing Rain serial
interface board
(P/N M404806)
Replace the serial
communication wires
between the DCP and
the Freezing Rain sensor
Contact AWI
Customer Service
+1 (916)928-1000
In the DCP, disconnect the white wire from the Freezing
Rain serial interface board TB1-1. Using the interface board
TB1-3 as a reference (with the black and shield wire still
connected), measure the DC voltage on TB1-1. Reconnect
the white wire. Was the voltage between -3 and -15 V?
In the Freezing Rain sensor, unplug J2. Using the
connector's black wire as a reference, measure the DC
voltage on the white wire. Reconnect J2. Was the
voltage between -3 and -15 V?
Review the status codes per the 1190
DCP User’s Manual (Screens 36–39),
and adjust or repair as needed
In the DCP disconnect the red wire from Freezing Rain serial
interface board TB1-2. Using the interface board TB1-3 as a
reference (with the black and shield wire still connected),
measure the DC voltage on the free red wire. Reconnect the red
wire. Was the voltage between -3 and -15 V?
Are Freezing
Rain data bad?
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.8 Freezing Rain Sensor
Are WMSCR/
NADIN data
missing?
46
Remove, test, and reconnect
WMSCR router power and
Ethernet connections
Use a browser to connect
AWOS Net URL. Are AWOS
Net data missing?
Confirm that VPN link is
up and that there is a
route to the VPN gateway
Reprogram AWOS Net to match
local network configuration
Remove, test, and reconnect
Ethernet to AWOS Net. Cycle
power off/on to AWOS Net..
Reprogram
WMSCR router
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Contact AWI
Customer Service
+1 (916)928-1000
Cycle power off/on
to AWOS Net
Contact AWI
Customer Service
+1 (916)928-1000
Reconnect RS-232
to AWOS Net
Replace
WMSCR router
Repair data connection
between AWOS Net and
CDP
Remove, test, and
reconnect DC power to
AWOS Net
Replace AWOS Net
Remove RS-232 from AWOS Net
and hook to laptop terminal
emulator program at 9600-8-N-1. Is
periodic text/numeric data visible?
Does AWOS Net display
the wind dial at all (even
with no data)?
Hook display to local AWOS
Net appliance. Are AWOS Net
data missing?
Contact AWI
Customer Service
+1 (916)928-1000
Are AWOS Net
data missing?
Replace ADAS router
Reprogram ADAS router
Remove, test, and reconnect
ADAS router power and
Ethernet connections
Are ADAS data
missing?
Contact AWI
Customer Service
+1 (916)928-1000
T R O U B L E S H O O T I N G
G U I D E
AWOS 3000 MAINTENANCE
5.9 Data Networking
6
F O R M S
Chapter
Forms
The following pages contain master forms for recording maintenance data. These master
forms should be copied and sufficient copies stored at a convenient location in each site's
Facility Reference Data File (FRDF). The Annual Technical Performance Record is to be
completed at system commissioning, after major repair work, and during annual
revalidation.
47
AWOS Monthly Technical Performance Record
Site Name and Location ___________________________________
General
Notify local users AWOS may be missing or unreliable during inspection
DCP/Tower
Press maintenance switch
Remove debris from all sensors
Check for mechanical damage
Check for movement of wind speed and direction sensors (2020/2030)
Check operation of MARS fan
Check obstruction lights
Sensors
Check all sensor hardware and cables
Clean Rain Gauge funnel
Check Rain Gauge heaters (6021)
Clean Visibility Sensor optics
Clean Day/Night Sensor optics
Clean Ceilometer optics
Check Ceilometer blower
Clean Present Weather Sensor lenses
Clean Thunderstorm/Lightning Sensor surface
Clean Freezing Rain Sensor probe
Central Data Platform
Check display operation
Check keyboard and mouse operation
Check printer operation, replace ribbon and paper as necessary
Check system clock
Check microphone by recording a voice remark
Check dial-up by dialing the CDP from an outside line
Check VHF by listening to AWOS voice output from a remote receiver
Check speaker operation
Check UPS operation
Record AWOS Observations
Time and Date
Wind Direction
Wind Speed
Visibility
Sky Condition (Clouds)
Precipitation
Present Weather
Thunderstorm/Lightning
Freezing Rain
Temperature
Dew Point
Altimeter Setting
Note any "missing" parameter or any other obvious failures:
System Checked By: ____________________________
Date _______________
Completed
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
_____
_____
_____
Data
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
_________________
Date/Time: ___________________
AWOS Triannual Technical Performance Record
Site Name and Location ___________________________________
Date _______________
General
Notify local users AWOS may be missing or unreliable during inspection
Complete AWOS Monthly Technical Performance Record
Expected
Measured
DCP/Tower
Drain and clean pressure port
ADC Vref0–5
__________
ADC Vref+
4090 – 4095
__________
AWOS wind direction seems reasonable
± 30º
__________
AWOS wind speed seems reasonable
± 5 kts
__________
BP1 (Reference Pressure) – (Sensor Pressure)
±0.005 in Hg
__________
BP2 (Reference Pressure) – (Sensor Pressure)
±0.005 in Hg
__________
(AWOS Temp) – (Measured Temp)
±2°F
__________
(AWOS Dew Point) – (Measured Dew Point)
±3°F
__________
DCP shows “MARS Fan Fail” with fuse F1 pulled
Expected
Measured
Visibility
Rotate sensor to avoid direct sun
Calibration Difference
±3%
__________
Rotate sensor back
Day/Night Sensor changes state
Cloud Height Sensor
Inspect and clean blower intake and outlets
System status LED (red) alternates between on and fast blink
Battery Status LED (green) is on
Dirty Window LED (yellow) is off
Replace internal desiccant
Expected
Present Weather Sensor
Heater check
lens is warm
Carrier raw data field (Xnnn)
405–420
Lnnn
-30 to 50
Knnn
0 to 150
Hnnn
40 to 120
Tnnn
ambient ±5°C
Data field (W__)
blank
Status field (S0000)
all zeros
Thunderstorm/Lightning Sensor
Check sealant
Freezing Rain Sensor
Check hardware and cables, clean as necessary
System Checked By: ____________________________
Measured
__________
__________
__________
__________
__________
__________
__________
Completed
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
_____
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
_____
_____
Pass (Y/N)
_____
Pass (Y/N)
_____
Date/Time: ___________________
AWOS Annual Technical Performance Record
Site Name and Location ___________________________________
Date _______________
General
Notify local users AWOS may be missing or unreliable during inspection
Complete AWOS Monthly Technical Performance Record
Complete AWOS Triannual Technical Performance Record
Expected
DCP/Tower
Model 2020/2030 Vane/Cup
Wind direction align to benchmark
Wind direction linearity 90º;
±3º, no dropouts or irregularities
Wind direction linearity 180º
±3º, no dropouts or irregularities
Wind direction linearity 270º
±3º, no dropouts or irregularities
±5% (DCP reading shows 359°–001°
in 355°–005° deadband),
Wind direction linearity 360º
no dropouts or irregularities
Wind speed
79 – 81 knots
Wind vane and anemometer bearings turn freely
Model 2040 Ultrasonic Wind
Zero Wind Check
0 knots
Measured
__________
__________
__________
_____
_____
_____
__________
_____
Pass (Y/N)
_____
Pass (Y/N)
Check for level using built-in bubble level
Expected
_____
_____
_____
_____
__________
__________
Rain Gauge
VHF Radio
Completed
_____
_____
_____
Pass (Y/N)
Measured
Perform the following at the VHF radio
Output Power Level
2.5 W, ±1 W
________________
Reflected Power
________________
Initial: 2.0:1 max.
VSWR
Operating: 3.0:1 max.
________________
Frequency
assigned:
________________
±1.0 kHz
________________
Modulation
65–95%
________________
Perform the following at the VHF antenna when cable runs are longer than 50 ft
Output Power Level
1.0 W, ±0.5 W
________________
Reflected Power
________________
Initial: 2.0:1 max.
VSWR
Operating: 3.0:1 max.
________________
_____
_____
_____
_____
_____
_____
_____
_____
Page 1 of 2
AWOS Annual Technical Performance Record (cont’d)
DCP UHF Radio
Power Level
Reflected Power
Expected
1 W, ±0.5 W
Measured
________________
________________
Initial: 2.0:1 max.
Operating: 3.0:1 max.
________________
________________
Assigned:
Frequency
________________
±1.5 kHz
Deviation
2.4 – 3.8 kHz
________________
Expected
Measured
CDP UHF Radio
Perform the following at the UHF radio
Power Level
1 W, ±0.5 W
________________
Reflected Power
________________
Initial: 2.0:1 max.
VSWR
Operating: 3.0:1 max.
________________
________________
Assigned:
Frequency
________________
±1.5 kHz
Deviation
2.4 – 3.8 kHz
________________
Perform the following at the CDP UHF antenna when cable runs are longer than 50’
Power Level
0.2W, ±0.15W
________________
Reflected Power
________________
Initial: 2.0:1 max.
VSWR
Operating: 3.0:1 max.
________________
Pass (Y/N)
_____
_____
VSWR
CDP
No active alarms/alarms cleared
_____
_____
_____
Pass (Y/N)
_____
_____
_____
_____
_____
_____
_____
_____
Pass (Y/N)
_____
Comments/Notes:
System Checked By: ____________________________
Date/Time: ___________________
Page 2 of 2
All Weather Inc.
1165 National Drive
Sacramento, CA 95818
Fax: 916.928.1165
Phone: 916.928.1000
Toll Free: 800.824.5873
3000-027
Revision E
May, 2011