SampleRAE - Cole

Operation & Maintenance Manual
Document Number: 010-4011-000
April 2003, Revision C1
For European Applications
The SampleRAE Automatic Sampling Pump (ASP-2000) is
intrinsically safe for use in the following areas:
0575 II 1G
DEMKO 03 ATEX 0204759X
Eex ia IIC T4
B. Recharge batteries only in non-hazardous locations.
C. Do not connect external cable to serial interface jack in
hazardous locations.
D. Use RAE Systems Adapter P/N 500-0072 for connection to
communication port and charging jack only in a nonhazardous area.
-READ BEFORE OPERATINGThis manual must be carefully read by all individuals who
have or will have the responsibility for using, maintaining,
or servicing this product. The product will perform as
designed only if it is used, maintained, and serviced in
accordance with the manufacturer's instructions.
To reduce the risk of electric shock, turn off power before
removing the monitor cover. Disconnect the battery
before removing sensor module for service. Never operate
the monitor while the cover is removed. Remove monitor
cover and sensor module only in an area known to be
The battery of the SampleRAE unit will discharge slowly
even if it is turned off. If the unit has not been charged for
7-10 days, the battery voltage will be low. Therefore, it is a
good practice to always charge the unit before using it. It
is also recommended to fully charge the unit FOR AT
LEAST 10 HOURS before first use. See section 5 for more
information on battery charging and replacement.
The instrument should be calibrated with a standard flow
meter before each day’s use.
For safety reasons this equipment must be operated and
serviced by qualified personnel only. Read and understand
instruction manual completely before operating or servicing.
Batteries: Use only RAE Systems battery packs, part nos.
012-3050 or 012-3052. This instrument has not been tested in
an explosive gas/air atmosphere having an oxygen
concentration greater than 21%. Substitution of components
may impair intrinsic safety. Recharge batteries only in nonhazardous locations.
Static Hazard: Clean only with damp cloth.
Pour des raisons de sécurité, cet équipement doit être utilise,
entretenu et répare uniquement par un personnel qualifie.
Etudier le manuel d’instructions en entier avant d’utiliser,
d’entretenir ou de réparer l’équipement.
Des Batteries: Utiliser seulement L'ensemble de batterie RAE
Systems, la référence 012-3050 au 012-3052. Cet instrument
n’a pas été essaye dans une atmosphère de gaz/air explosive
ayant une concentration d’oxygène plu élevée que 21%. La
substitution de composants peut compromettre la sécurité
intrinsèque. Ne charger Les batteries que dans emplacements
désignés non dangereux.
Danger risque d’origine électrostatique : Nettoyer
uniquement avec un chiffon humide.
Table of Contents
1. GENERAL INFORMATION ........................... 1-1
General Specifications ............................... 1-2
2. OPERATION OF SAMPLERAE .................... 2-1
Physical Description .................................. 2-2
Keys and Display ....................................... 2-3
Power On/Off ............................................. 2-4
Operation ................................................... 2-5
2.4.1 Sampling Operation............................. 2-6
2.4.2 Programming Operation ...................... 2-8
Alarm Signals........................................... 2-12
Back Light ................................................ 2-13
Remote Sampling Operation.................... 2-14
Battery Charging Operation ..................... 2-15
Sample Bag Collection............................. 2-17
3. THEORY OF OPERATION............................ 3-1
4. MAINTENANCE............................................. 4-1
Battery Replacement ................................ 4-1
Pump Replacement ................................... 4-5
Inlet Filter Replacement ............................. 4-7
5. TROUBLESHOOTING................................... 5-1
Special Diagnostic Mode ........................... 5-2
Troubleshooting Table ............................... 5-7
SampleRAE is a hand held, battery powered,
programmable Automatic Sampling Pump. It is designed
to accept industry standard gas detection tubes or
sorbent tubes. The user can program the sampling
volume. A built-in flow sensor measures the exact
amount of sample volume and then shuts off the pump
Lightweight and Compact
16 oz (454 g), Telephone handset size
Dependable and Accurate
More than 16 hours of running time with the
microcontroller, using alkaline or rechargeable
User Friendly
Menu driven, intuitive end-use operation
SampleRAE (ASP-2000) kit includes:
Automatic sampling pump unit
Battery charger (for rechargeable versions)
Spare tube adapter
Alkaline battery adapter
Dust filter
Calibration accessories
1.1 General Specifications
Table 1.1 Automatic Sampling Pump Specifications
Size 7.5"L x 2.75"W x 1.5"H
Weight 16 oz with battery pack
Battery 4 AA size alkaline batteries or
rechargeable Ni-Cad battery pack
(snap in, field replaceable)
Operating Hours 20 hours continuous sampling with
alkaline battery or 16 hours with
rechargeable battery
Battery Charging 10 hours through built-in charger
or an external battery charger
Display 1 line by 8-character dot matrix
LCD (0.4” character height)
Inlet tube Adapter accepts industry standard 5 to10
mm gas detection or gas sorbent
Outlet Adapter 5/32” barb connection to collect air
sample into Tedlar sampling bags
Direct Readout accumulated sample volume,
remaining run time, battery voltage
and operating mode
Intrinsic Safety UL & cUL Class 1, Division I,
Groups A,B,C,D, Non-hazardous
locations only (US & Canada)
0575 II 1G
DEMKO 03 ATEX 0204759X
Eex ia IIC T4 (Europe)
Operating Mode detection tube or sorbent tube
Flow Rate flow calibration using external flow
Calibration meter
Sampling Volume user programmable from 50 to
1,000 cc in 50 cc increments for
detection tube or 0.1 to 500 liter in
0.1 liter increments for sorbent
Audible Alarm 90 dB buzzer @ 10 cm
Visual Alarm flashing red LED
EM Interference no effect when exposed to 0.43
mW/cm2 RF interference ( 5 watt
transmitter at 12 inches )
Temperature 0o to 45oC (32o to 113oF)
Humidity 0% to 95% relative humidity (noncondensing)
Housing metal plated plastic, splash and
dust proof, will withstand 3’ drop
Attachment Wrist strap
The SampleRAE Unit is a hand-held automatic
sampling pump. It allows a single hand operation to
collect gas samples into gas detection tubes or
sorbent tubes. Prior to factory shipment the
SampleRAE is pre-calibrated with an external flow
meter. However, the user should calibrate the
instrument with a standard flow meter before the first
use. After the unit is fully charged and calibrated, it is
ready for immediate operation.
Gas detection or
sorbent tubes
Light sensor
LED light
Liquid crystal display
Key pads
Wrist strap
Exit port
Figure 2-1 SampleRAE Unit
2.1 Physical Description
The main components of the SampleRAE automatic
sampling pump include:
Three keys for user to interact with the unit:
1 operation key
2 programming keys for normal operation or
programming of the unit
Liquid crystal display with back light for direct readout
and calculated measurements
Buzzer and red LED for alarm signal whenever the
pump operation is completed
Wrist strap
Ambient light sensor
Charge contact for plugging directly to the charging
Charging status indicator LED
Gas entry and exit ports
2.2 Keys and Display
Light sensor
Alarm LED’s
Charge LED
50.0 cc
Figure 2-2 Keypad and Display on Front Panel
Key Function in Normal Operation
[MODE] Turn on/off the power* and step through
menu items
[N/-] Negative acknowledgement or decrement
[Y/+] Start measurement, positive
acknowledgement or increment value
* Pressing and holding [MODE] for 5 seconds turns off the power to
the unit. Unit will beep once per second and display a count-down
timer during power-down sequence. Press [MODE] momentarily to
step through menu items. To save time, press any key during
message scrolling to skip to the end of the message.
The SampleRAE includes a one line, eight digits,
alpha/numeric, 5x7 dot matrix LCD display. The LCD
displays the operation and programming menu and error
2.3 Power On/Off
Turn on the SampleRAE automatic sampling pump by
pressing [MODE] for one second and then releasing it.
The audio buzzer will beep once and the display will
show “ON!..” and then “Ver n.nn” to indicate the unit’s
current firmware version number. The model number and
battery voltage are displayed. Then the display shows the
currently selected operation mode: detection tube or
sorbent tube, followed by the programmed sample
volume. The display then shows “Start?” to indicate that
the unit is ready to start sampling operation.
Turn off the SampleRAE automatic sampling pump by
pressing and holding [MODE] for 5 seconds. The unit will
beep once per second during the power-down sequence
with a count down timer showing the number of
remaining seconds. The message “Off!...” flashes on the
LCD display and the display will go blank indicating that
the unit is turned off.
2.4 Operation
The SampleRAE offers following two operation modes:
Detection Tube Mode
In this mode, the SampleRAE turns on the pump and
pulls in a fixed volume of gas sample into a gas detection
tube. Users can program the volume from 50 cc to 1000
cc in 50 cc increments. While the pump is running, the
accumulated sample volume is displayed. When the
programmed volume is reached, the pump will stop
automatically. The user can NOT access other menus
while the pump is running. Pressing any key while the
pump is running will abort the sampling operation.
Sorbent Tube Mode
In this mode, the SampleRAE turns on the pump and
pulls in a fixed volume of gas sample into a sorbent tube.
The volume can be programmed from 0.1 liter to 500 liter
in 0.1 liter increments. While the pump is running, the
accumulated sample volume and the estimated
remaining run time are displayed. When the programmed
volume is reached, the pump will stop automatically.
While the pump is running, the user CAN access other
programming menu by pressing [MODE]. The user can
also stop the pump by pressing [Y/+] when the display
shows a “Stop?” message.
After the SampleRAE is turned on and cycles through the
start up displays, the current operation mode and
programmed volume will be displayed followed by a
“Start?” message. At this point, the user has two options:
1) start sampling operation, or 2) step through the
programming menu.
2.4.1 Sampling Operation
The sampling operation involves the following sampling
Tube Preparation
Insert tube
Start sampling
Display volume and time
Remove tube
Unit is ready to start sampling. The display shows a
“Start?” message.
Tube Preparation
Break both ends of a new detection or sorbent tube using
the tip cutter on the tube cap of the SampleRAE. The
tube contents may be hygroscopic and should be used
within a short time of opening of the tube.
CAUTION: Wear hand and eye protection when breaking
tube tips. Use caution in handling tubes with broken
ends. Keep away from children. Detection or sorbent
tubes should be disposed of according to local
Tube insertion
Insert the tube securely into the tube inlet of the
SampleRAE with the tube arrow pointing towards the
Start Sampling
Press [Y/+] to start the sampling pump.
Display Volume and Time
While the pump is running, the accumulated volume will
be displayed in units of cc or liter. The estimated
remaining run time will also be displayed in the sorbent
tube mode. When the programmed volume is reached,
the pump will stop and a message “Done!” and “Remove
Tube!” will be displayed for 2 seconds. The LED will flash
once and the buzzer will sound for 1 second to indicate
the completion of the sampling operation.
Tube Removal
Remove the tube from the tube inlet. Dispose the tube
according to local regulations.
Abort Sampling
During waiting period of detection tube operation, any
key pressed will abort the sampling operation. While the
display shows “Stop?” menu in sorbent tube mode, press
the [Y/+] key will also abort the sampling operation. The
accumulated volume will be displayed in this case.
2.4.2 Programming Operation
While the display shows “Start?” menu, press [MODE] to
step through the programming menus, which are
arranged in a “round robin” order. To choose a specific
display, press [MODE] one or more times until the
desired display appears.
Bat=4.8 V
Tube Type?
1) Start?
The pump is ready for sampling operation. Press
[MODE] to advance to the next menu. If a tube is
inserted at this point, [Y/+] can be pressed to start a
sampling. (See section 2.4.1).
2) Change Volume?
This menu allows users to change the programmed
sample volume. Press [Y/+], the currently programmed
volume will be displayed. Press [Y/+] to increment the
volume and [N/-] to decrement the volume. Press
[MODE] to exit the volume change menu. If the volume is
changed from a previously saved value, a “Save?”
message will appear. Press [Y/+] to confirm the change.
Press [N/-] or [MODE] to discard the change and
advance to the next menu. If user does not want to
change the volume, press [MODE] or [N/-] to skip to the
next menu.
3) Calibrate Flow?
This menu allows users to calibrate the flow sensor inside
the SampleRAE. An external flow meter, an accurate gas
flow calibrator or a mass flow meter*, is required to
perform the following calibration procedure. Press [Y/+]
to proceed.
*If an external flow meter is not available, user can use
the calibration tube as a simple (but less accurate) flow
standard. A typical calibration tube will provide a flow rate
between 120 to 140 cc per minute. The flow rate of each
tube is measured in the factory and recorded on the
plastic bag. However, this flow rate changes as the pump
ages, and therefore an external flow meter is ultimately
Zero calibration
The display shows a message “Zero….” for 4 seconds
followed by a “Continue” message. The flow sensor zero
point is calibrated automatically and the unit displays the
next submenu.
Span calibration
The pump is turned on and the display shows a flow
reading “XXX ccm” where XXX is the flow rate in cc per
minute based on previous calibration. Insert the
calibration tube into the tube inlet of the SampleRAE.
Note: make sure that the arrow on the calibration tube is
pointing toward the inlet of the SampleRAE. Connect an
external flow meter to the open end of the calibration
tube. Measure the actual flow rate from the external flow
meter. Press [Y/+] to increment the flow value and [N/-]
to decrement the flow value so that it matches the actual
flow rate reading of the external flow meter. Press
[MODE] to exit the flow rate change menu. A “Save?”
message will appear. Press [Y/+] to confirm the change
and save the new calibration value. Press [N/-] or
[MODE] to abort and exit the calibration submenu.
Note: In order to achieve the best flow accuracy, it is
recommended that the actual detection or sorbent tube
be used during the calibration procedure together with an
external flow meter.
4) Change Tube Type?
This menu allows users to change the operation mode of
SampleRAE. Press [Y/+], the current mode (Detection or
Sorbent) is displayed. Press [N/-] to toggle to the other
mode. Press [Y/+] to accept the current mode. Press
[MODE] to exit the mode change menu. If the operation
mode is changed from a previously saved one, a “Save?”
message will appear. Press [Y/+] to confirm the change.
Press [N/-] or [MODE] to discard the change and
advance to the next menu.
5) Bat=4.8V
This menu displays the current battery voltage of
SampleRAE. Press any key to continue to the next menu.
Note: a fully charged battery pack should show 4.8 volts
or higher. When the battery voltage falls below 4.4 volts,
a flashing “Bat” will appear as a warning message. There
is about 20-30 minutes of run time left before the
SampleRAE will be turned off automatically when the
battery voltage falls below 4.2 volts.
6) Stop?
In sorbent tube operation mode, if the pump is already
running, the “Start?’ menu will be changed to a “Stop?”
menu. Press [MODE] to advance to the next menu. Press
[Y/+] to stop the pump and abort the sampling operation.
The accumulated sample volume up to this point will be
Correction Factors
In Detection Tube Mode, it is sometimes necessary to
multiply the final readings by a correction factor (CF)
specific for the type of tube. This occurs because the
tubes are calibrated with a hand pump that has a
different flow pattern than the SampleRAE. A list of
correction factors is given in Technical Note 154 at In most cases, the corrections are
minor and lead to a <10% to 15% overestimation and
therefore err on the safe side, and the correction might
be omitted. However, for some tubes, the corrections are
more significant and must be used. For best accuracy the
user should test their sample gas and tube batch with
both the Hand Pump and SampleRAE to obtain a more
accurate correction factor to apply to subsequent
SampleRAE tube readings.
2.5 Alarm Signals
At the end of each sampling period, the buzzer and red
flashing LED are activated once to indicate the
completion of the sampling operation. If the operation is
aborted, the buzzer and red flashing LED will be
activated twice.
In addition, the SampleRAE will alarm if the battery
voltage falls below a pre-set voltage level (4.4 V). When
the low battery alarm occurs, the red LED will flash once
a second and the buzzer will beep once a minute. There
will be approximately 20-30 minutes of operating time
left. When the battery voltage falls below 4.2 V, the unit
will be turned off automatically.
Alarm Conditions and Signals
Alarm Signal
Complete Operation
1 beeps/flash plus “Done!”
message in LCD
Abort Operation
2 beeps/flash plus “Abort!”
message in LCD
Low battery
1 flash per second, 1 beep per
minute plus “Bat” message in
2.6 Back Light
The LCD display is equipped with an LED back light to
assist in reading the display under poor lighting
The ambient light is sensed continuously and the back
light will be turned on automatically if the ambient light is
below a threshold level. The back light will be turned off
automatically when the ambient light exceeds the
threshold level.
See section 5.1 for instructions on how to set the
threshold level of the back light.
Note: The LED back light consumes a higher amount of
energy from the battery and shortens the operating time
of the unit by 20 - 30%.
2.7 Remote Sampling Operation
The SampleRAE includes an integrated diaphragm pump
that provides a minimum flow rate of 250 cc per minute
(with no tube in place). Connecting a 1/4 inch Tygon
tubing with 1/8 inch inside diameter to the gas inlet port
of the SampleRAE, this pump can pull in air sample from
200 feet away horizontally, or 90 feet vertically.
Note: When the SampleRAE is pulling gas sample from a
remote location, it is necessary to account for the volume
inside the long tubing so that the total sample volume is
calculated correctly. See Technical Note 140 for
details on tubing volumes and delay times.
Remote sampling hoses of 15 feet (P/N 010-3009015) and 35 feet (P/N 010-3009-035) are available
with direct connection to the SampleRAE and with a
tube holder at the end of the hose.
2.8 Battery Charging Operation
The SampleRAE operates conveniently with alkaline
batteries, but offers a rechargeable Ni-Cad battery pack
as an option. The charging circuit is built into the
SampleRAE unit. It only needs a regular AC to 12 V DC
adapter (wall mount transformer) to charge the
rechargeable battery pack inside the unit.
1. Connect the AC adapter (or the optional automotive
charging adapter) to the DC jack on the SampleRAE
unit. If the unit was off, it will automatically turn on.
2. The first message displayed will be “Deep discharge?”
This message will remain on the display for three
seconds. If the user wants to discharge the battery
pack, affirm this query with [Y/+], otherwise the unit
will skip this function and move on to the charge
mode after 3 seconds.
Note: deep discharge recovers the Ni-Cad battery
from a memory effect and it is needed only when the
battery run time is below normal. Deep discharge may
take up to 10 hours depending on the charge level in
the battery.
3. While charging, the display message will alternate
between “Charging” and “Bat=x.xV” (x.x is the present
battery voltage). The LED should be red in color when
4. When the battery is fully charged, the LED will change
from red to green and the message “Fully charged”
will appear on the display. The red color indicates that
the battery is being charged. The green color
indicates that the battery is fully charged. After the
battery is fully charged, the unit will enter the “trickle
charge” mode. In this mode, the red LED will turn on
for two or three seconds, every minute, to maintain
the full charge and avoid overcharging.
A completely discharged SampleRAE unit will be charged
to full capacity within 10 hours. The battery will be
drained slowly even if the unit is turned off. If the unit has
not been charged for 7-10 days, the battery voltage will
be low.
The factory supplied Ni-Cad battery is designed to last for
16 hours of normal operation (no alarm, no back light
condition), for a new battery under the best conditions.
As the battery becomes older or is subject to adverse
conditions, like cold ambient temperatures, the battery
capacity will be reduced significantly.
The unit can be run off a wall mount adapter, as long as
the rechargeable battery is in place.
CAUTION: A unit plugged into a wall mount adapter is
NOT considered intrinsically safe.
2.9 Sample Bag Collection
The SampleRAE can be used to collect a fixed amount of
gas into a sample collection bag for analysis or other
An outlet adapter is provided in the standard SampleRAE
kit. Connect a sample collection bag to the outlet adapter
through a short piece of Tygon* tubing. Screw the outlet
adapter into the exit port on the side of the SampleRAE
unit. Make sure that the O-ring of the outlet adapter is in
place so that it can make an air tight seal between the
outlet adapter and the exit port.
* Because Tygon absorbs or reacts with many chemicals,
Teflon or metal tubing is recommended for any sections
longer than a few inches.
Program the sample volume through the programming
menu (see Section 2.4.2). Press [Y/+] to start the pump.
When the desired volume of sample gas is collected in
the bag, the pump will shut off automatically.
The SampleRAE unit uses a miniature diaphragm pump
to pull a fixed amount of gas sample into a detection tube
or a sorbent tube. An electronic flow sensor inside the
unit measures the actual gas flow and integrates the total
sample volume every 0.5 second. The exhaust gas exits
through a port on the side of the housing.
LCD display
flow sensor
or sorbent
Figure 3-1 SampleRAE Block Diagram
During detection tube sampling operation, the flow
pattern of the colorimetric tube is taken into consideration
and the sample volume is adjusted to compensate for the
flow pattern effect on the detection tube. (See Technical
Note 154 for further corrections.) During sorbent tube
operation, exact volume is calculated based on the flow
rate without any compensation. A single chip
microcomputer is used to control the operation of the
alarm buzzer, LED, pump and light sensor. It measures
the flow sensor readings and calculates the total sample
volume based on calibration data. A two-point calibration
is used to calibrate the sensor to a known flow rate and
zero flow (i.e. no flow). The calibration data are stored in
non-volatile memory. A liquid crystal display consisting of
a single row of eight alpha/numeric characters is used to
display the volume readings and menu messages. The
user interacts with the unit through three keys on the
front panel keypad.
The unit is powered by a rechargeable Ni-Cad battery, or
an alkaline battery pack.
NOTE: The printed circuit board of the unit is connected
to the battery pack even if the power is turned off.
Therefore, it is very important to disconnect the battery
pack before servicing or replacing any components inside
the unit. Severe damage to the printed circuit board may
occur if the battery pack is not disconnected before
servicing the unit.
To reduce the risk of ignition of hazardous
atmospheres, recharge battery only in an area known
to be non- hazardous. Remove and replace battery
only in an area known to be non- hazardous.
Ne charger les batteries que dans emplacements
désignes non dangereux.
The major maintenance items of the SampleRAE are:
Battery Pack
Sampling Pump
Inlet connectors and filter
4.1 Battery Replacement
When the display shows a flashing message “Bat”, the
battery requires replacement or recharging. The battery
may be replaced in the field (in area known to be nonhazardous) if required. If a rechargeable battery pack is
used, it is recommended to recharge the SampleRAE
unit upon returning from fieldwork. A fully charged battery
powers a SampleRAE unit for 16 hours continuous
operation. The charging time is less than 10 hours for a
fully discharged battery. The built-in charging circuit is
controlled by two-step constant voltage / constant current
charging to prevent over-charging.
To reduce the risk of ignition of hazardous
atmospheres, recharge battery only in area known to
be non- hazardous. Remove and replace battery only
in area known to be non- hazardous.
Battery Cover
Battery Pack
Wrist strap
Figure 4-1 Replacing the Battery
1. Turn off power to the SampleRAE.
2. Unscrew the two battery compartment screws,
located on the bottom of the unit, and remove the
3. Remove the battery from the battery compartment.
4. Connect the rechargeable battery pack to an external
charging station (optional) for charging if necessary.
5. Replace a fully charged spare battery pack inside the
battery compartment. Make sure the battery pack is
oriented properly inside the compartment by aligning
the pins on the unit with the contacts on the battery
6. Close the battery compartment cover and tighten the
two screws.
Replacing Alkaline Battery Adapter
An alkaline battery adapter is supplied with each
SampleRAE kit. It accepts four AA size alkaline batteries
and can be used in place of the rechargeable battery
pack to provide approximately 20 hours of operation.
1. Insert four fresh AA size alkaline batteries into the
alkaline battery adapter. Make sure that the polarity of
the batteries is correct.
2. Follow the same procedure as described above to
replace the battery adapter.
The internal charging circuit is designed to prevent
charging to alkaline batteries when alkaline batteries are
installed. Plugging a wall mount adapter into the unit with
alkaline batteries will not charge the batteries.
Note: The AA Alkaline battery adapter supplied by RAE
Systems Inc. is intrinsically safe!
4.2 Pump Replacement
The sampling pump is a positive displacement diaphragm
pump. When approaching the end of the specified life
time of the pump, it will consume higher amount of
energy and reduce its sample draw capability
significantly. When this occurs, it is necessary to replace
or rebuild the pump.
To check the pump flow, connect the inlet port to an
external flow meter (such as the mass flow meter, gas
flow calibrator or a floating ball flow meter). The flow
should be greater than 250 cc/min.
Battery Cover
Bottom Cover
Top Cover
Figure 4-2 Replacing the Pump
Pump Replacement
1. Turn off SampleRAE power.
2. Open the battery cover, remove the battery pack,
unscrew the six screws to open the bottom cover.
3. Unplug the pump from the PCB. Unscrew the two
screws that hold the pump assembly to the PCB.
Disconnect the Tygon tubing that connects the pump
to the gas inlet port and exit port.
4. Replace a new pump assembly. Connect the Tygon
tubing to the gas inlet port. Plug the pump connector
back into the PCB and screw down the pump
assembly to the board.
5. Replace the bottom cover and tighten the six screws.
Replace the battery pack and its cover.
4.3 Inlet Filter Replacement
The SampleRAE inlet consists of a rubber tube adapter
and a porous metal dust filter. The standard rubber tube
adapter will accept 5 to 8 mm gas detection or sorbent
tubes. If a 10 mm tube is used, a special rubber tube
adapter is needed. The rubber tube adapter needs to be
replaced when it becomes worn from repeated inserting
and removing tubes. Figure 4-3 shows the drawing of the
inlet assembly.
Figure 4-3 Inlet Filter Assembly
The porous metal filter prevents dust or glass debris from
entering into the sampling pump. It needs to be replaced
periodically so that it will not be clogged by the dust and
glass debris. To replace the metal filter, first remove the
pump adapter nut by unscrewing the nut counter
clockwise. Pull out the tube adapter from the unit. Use a
screw driver to pop out the metal filter by pushing from
the open end of the tube adapter. Insert a new filter into
the rubber adapter. Place the tube adapter with the filter
back into the unit and screw down the pump adapter nut.
To aid the user in diagnosing the unit, the unit has a
special diagnostic mode that can display critical, low level
parameters. Section 5.1 describes the operation of the
diagnostic mode. Section 5.2 summarizes the frequently
encountered problems and suggested solutions. Turning
on the SampleRAE unit in diagnostic mode and using the
troubleshooting table in Section 5.2, the user can usually
narrow the problem down to one or two areas and correct
the problem without having to return the unit for repair.
The diagnostic mode allows the user to set several
low level parameters that are very critical to the
operation of the unit. Extra care should be taken
when setting these low level parameters. If the user
is not familiar with these parameters and sets them
incorrectly, it may cause the unit to shut down or
malfunction. Use by qualified personnel only.
5.1 Special Diagnostic Mode
To place the unit into the special diagnostic mode, first
turn the unit off. Next push and hold [Y/+], while still
holding [Y/+], also push and hold [MODE] for at least two
seconds. After the required delay, release both keys, the
unit will now go through the normal start-up display
sequence and display a “Diagnostic mode” message. At
the end of the special mode start-up, the display will
show the message “VAC xxxx”. This is the first diagnostic
menu. Other diagnostic menus of the unit are available
as shown below. They can be reached by pressing
[MODE] repeatedly until the desired parameters are
Table 5-1 Diagnostic Mode Menu
Key Action
Raw reading
Off reading
Flow reading
Adjust Pump?
Calibrate Flow?
LCD contrast
Pump current
Alarm On/Off?
Ambient light
Back light threshold
PC Communication?
The following is a brief description of the diagnostic
1) Raw reading
The raw sensor readings are displayed as “VAC xxxx”
where xxxx is a 4 digit number. This raw sensor reading
provides a quick diagnosis on the response and the
sensitivity of the flow sensor while the pump is running.
The sensor should read above 3000 when there is no
blockage to the inlet port. Block the inlet port with a
finger, the sensor reading should drop to 1800 or less. If
the raw reading is not changing or falls outside this
range, the flow sensor or the associated electronics may
be defective.
2) Off reading
The pump is turned off and the raw sensor reading is
displayed. This reading provides a quick diagnosis on the
base line signal of the flow sensor while the pump is
turned off. The sensor reading should be between 1200
to 1800. If the raw reading is outside of this range, the
flow sensor or the associated electronics may be
3) Flow Reading
This menu provides a quick diagnosis on the calibration
of the flow sensor. The pump is turned on and the
calibrated flow reading is displayed as “xxx ccm” where
the flow rate is expressed in cubic centimeter per
minute. Connect an external flow meter to the inlet port.
Compare the flow meter reading with the displayed
reading. If the flow reading is more than 10% off the
external flow meter reading, it is necessary to perform a
new flow calibration to maintain the flow measurement
4) Adjust Pump?
This menu allows the user to adjust the pump drive to
increase or decrease the power delivered to the pump.
Note: In most cases pump drive adjust is not
required, in which case the user should press [MODE] to
exit this display. If the user want to adjust the pump,
press [Y/+]. The current pump drive is displayed. The
nominal value of the pump drive is set to 250. The
maximum drive is 255 and it is the maximum power to be
delivered to the pump. [Y/+] can be used to increase or
[N/-] to decrease the pump drive. When pump drive
exceeds 255, it returns to 0. If the pump drive value has
been changed, a message “Save?” will appear. Press
[Y/+] to confirm the change, [N/-] or [MODE] to discard
the changes.
5) Calibrate Flow?
This menu allows user to calibrate the flow sensor of the
SampleRAE unit using an external flow meter. The
calibration procedure is identical to that of Section 2.4.2.
However, in diagnostic mode, there is no error checking
of the flow sensor readings during calibration. Therefore,
any sensor reading is considered valid. If the user
accidentally entered a wrong value or performed an
illegal operation during regular calibration, this function
can be used to recover from the error.
6) LCD Contrast
This display allows the user to adjust the LCD contrast.
Press [Y/+] to increase the contrast and [N/-] to decrease
the contrast. The bar graph shows the current LCD
contrast setting. If the display appears blank or very faint,
press the [Y/+] several times to increase the contrast.
7) Pump Current
This display can be used to diagnose the operation of the
pump. The pump current is displayed as “Pump=xxx”.
When the pump is operated normally, the pump reading
should be between 4 to 12. When the inlet is blocked, the
pump reading should increase by 4 to 6. If the pump
reading is zero or does not change when the inlet is
blocked, the pump may be defective or there is a leak in
the inlet.
8) Alarm On/Off?
This display can be used to test the operation of the
alarm buzzer and red LED. The display shows “Alarm”
then “On?…”. Press [Y/+], the buzzer will beep and the
red LED will light up. The display shows “Off?..” Press
[Y/+] again to turn off the buzzer and LED. Press
[MODE] to move to the next menu.
9) Ambient Light
This display can be used to diagnose the operation of the
ambient light sensor. The present light sensor reading is
displayed as “Lite=xxx”. In a brightly lit room, the light
sensor reading should be above 130. The user can
shade the light sensor (which is located at the upper left
corner of the display membrane) with their hand and
watch the light sensor reading. The light sensor reading
should drop to less than 100. If the light sensor reading is
outside this range or does not change when the sensor is
blocked, the light sensor or associated electronics may
be defective.
10) Back Light Threshold
This display can be used to adjust the LCD back light
turn on and off threshold level. The display shows the
current threshold level as “Trip=xxx”. First determine the
appropriate light level to turn on the back light from the
previous menu. Use [Y/+] or [N/-] to increase or decrease
the trip value until it is about the same as the previously
determined threshold value. Press [MODE] to exit this
display. If the threshold value is changed, a message
“Save?” will appear. Press [Y/+] to confirm the change,
[N/-] or [MODE] to abandon the changes.
11) PC Communication?
This function allows the unit to communicate directly with
a PC through the serial port. This function is reserved for
advanced diagnostic capability by an authorized service
5.2 Troubleshooting Table
Table 5-2
Cannot turn on
power after
charging the
Discharged battery.
Defective battery.
Charge or replace
back light
Trigger level too
low, defective LED
or LCD back light.
Adjust trigger level.
“Bat” message in
Discharged battery.
Recharge battery.
Buzzer Inoperative
Bad buzzer.
Call authorized
service center.
Cannot turn off unit
or corrupted
characters in LCD
Disconnect and reconnect battery to
reset computer.
Calibration error
Defective flow
Disconnect, then
connect battery to
reset computer.
Call authorized
service center.
Call authorized
service center.
Incorrect flow set
Excessive pump
noise or no inlet air
Blocked inlet path.
Inlet flow too low
Pump diaphragm
damaged or has
debris. Flow path
leaks or blocked.
Defective pump.
Ensure correct
flow, replace
Check inlet
Replace a new
Check flow path for
leaks; sensor
module, Teflon
tube connection
Replace pump
RAE Systems, Inc. Main Office
1339 Moffett Park Drive
Sunnyvale, California 94089, USA
Contact Numbers
Instrument Sales
Tubes Sales
Technical Support
NOTE: Before returning the unit for service or repair,
please obtain a Return Material Authorization (RMA)
Number for proper tracking of your equipment. Packages
without RMA Numbers will be refused at the factory.
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