SERVICE MANUAL
Ohaus Corporation 7 Campus Drive, Suite 310, Parsippany, NJ 07054, USA +1 973 377 9000
SERVICE MANUAL
The information contained in this manual is believed to be accurate at the time of publication, but Ohaus
Corporation assumes no liability arising from the use or misuse of this material. Reproduction of this
material is strictly prohibited.
Material in this manual is subject to change.
© Copyright 2015 Ohaus Corporation, all rights reserved.
TM Registered trademark of Ohaus Corporation.
TABLE OF CONTENTS
Page No.
CHAPTER 1 GETTING STARTED
1.1
1.2
1.3
1.4
1.5
1.6
1.7
Introduction ................................................................................................................ 1-1
Definition of Signal Warning and Symbol .................................................................. 1-2
Safety Precautions..................................................................................................... 1-2
Service Facilities ........................................................................................................ 1-4
Tools and Test Equipment Required ......................................................................... 1-5
Test Mass Required................................................................................................... 1-5
Specifications............................................................................................................. 1-6
1.7.1 Admissible Ambient Conditions: Use only in closed rooms ................................ 1-7
1.8 Controls ..................................................................................................................... 1-8
1.8.1 Display ................................................................................................................ 1-9
1.9 Setup Navigation ..................................................................................................... 1-10
1.9.1 Setup Screen .................................................................................................... 1-10
1.9.2 Weight and Temperature Calibration................................................................ 1-10
1.9.2.1 Weight Calibration ................................................................................ 1-10
1.9.2.2 Temperature Calibration ....................................................................... 1-12
1.9.2.3 Last Temperature Calibration Data ...................................................... 1-14
1.9.3 Use Setting ....................................................................................................... 1-15
1.9.3.1 Language ............................................................................................. 1-15
1.9.3.2 Brightness ............................................................................................ 1-16
1.9.3.3 Beep ..................................................................................................... 1-17
1.9.4 Devise Setting .................................................................................................. 1-18
1.9.4.1 Date and Time ...................................................................................... 1-18
1.9.5 Peripherals ....................................................................................................... 1-20
1.9.6 Print .................................................................................................................. 1-21
1.9.7 Company Information ....................................................................................... 1-23
1.9.8 User Management ............................................................................................ 1-25
1.10 System and Data Management ............................................................................... 1-27
CHAPTER 2 TROUBLESHOOTING
2.1
Troubleshooting ......................................................................................................... 2-1
2.1.1 General Procedures for Troubleshooting ........................................................... 2-1
2.2 Problem Solver .......................................................................................................... 2-2
2.3 Testing ....................................................................................................................... 2-3
2.3.1 Operational Test ................................................................................................. 2-3
CHAPTER 3 MAINTENANCE PROCEDURES
3.1
Preventive Maintenance ............................................................................................ 3-1
3.1.1 Preventive Maintenance Checklist ..................................................................... 3-1
3.2 Opening the MB90 and MB120 ................................................................................. 3-1
3.2.1 Dismantling the Heating Module ........................................................................ 3-2
3.2.2 Replacing the Protective Glass and Reflector .................................................... 3-3
3.2.3.1 Removing Protective Glass and Reflector ................................................. 3-3
3.2.3.2 Installing Protective Glass and Reflector ................................................... 3-3
3.2.3 Replacing the Halogen Lamp ............................................................................. 3-3
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CHAPTER 3 MAINTENANCE PROCEDURES continued ........................................ Page No.
3.3
3.4
3.5
3.6
3.7
3.8
3.9
3.10
Replacing the Power PCB and Power Switch ........................................................... 3-4
Replacing the AC Plug Fuse ...................................................................................... 3-6
Replacing the AC Plug............................................................................................... 3-6
Replacing the Control Board ...................................................................................... 3-7
Replacing the Main PCB ............................................................................................ 3-8
Replacing the Load Cell............................................................................................. 3-9
Replacing the Load Cell Accessory kit .................................................................... 3-10
Replacing the Heating Chamber Parts .................................................................... 3-12
3.10.1 Opening the Heating Chamber Compartment .............................................. 3-12
3.10.1.1 Replacing the Temperature Sensor ................................................... 3-13
3.10.1.2 Testing the Temperature Sensor and Cable ...................................... 3-14
3.10.1.3 Replacing the Halogen Lamp ............................................................. 3-15
3.10.1.4 Replacing the Thermal Overload ........................................................ 3-17
3.10.1.5 Installing the Thermal Overload.......................................................... 3-18
3.10.1.6 Testing the Thermal Overload ............................................................ 3-19
3.10.2 Replacing the Top Housing Components ..................................................... 3-20
3.10.2.1 Removing the Top Housing Cast Iron Plate ....................................... 3-20
3.10.2.2 Replacing the Fan .............................................................................. 3-21
3.10.2.3 Replacing the Lid Sensor Board ......................................................... 3-22
3.10.2.4 Replacing the LCD Display ................................................................ 3-22
3.10.2.5 Replacing the Keyboard ..................................................................... 3-33
3.10.2.6 Replacing the Label ............................................................................ 3-33
CHAPTER 4 FINAL TESTING
4.1.
4.2
4.3
4.4
Final Testing .............................................................................................................. 4-1
Operational Test ........................................................................................................ 4-1
LCD Display Test ....................................................................................................... 4-1
Performance Test ...................................................................................................... 4-1
4.4.1 Precision Test ................................................................................................... 4-2
4.4.2 Repeatability Test ............................................................................................. 4-3
4.4.3 Linearity Test .................................................................................................... 4-4
CHAPTER 5 PARTS IDENTIFICATION & DIAGRAMS
5-1
MB90 and MB120: Housing and Parts ...................................................................... 5-2
Appendix A WEIGHT AND TEMPERATURE CALIBRATION
A.1 Weight Calibration .................................................................................................... A-1
A.2 Temperature Calibration ........................................................................................... A-4
Appendix B SOFTWARE SERVICE TOOL INSTRUCTION
B.1 Restore EEPROM..................................................................................................... B-3
B.2 Replace Main PCB ................................................................................................... B-5
B.3 Replace Control Board ............................................................................................. B-7
B.4 Diagnostics ............................................................................................................... B-9
B4.1 Ramp ON ....................................................................................................... B-10
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Appendix B SOFTWARE SERVICE TOOL INSTRUCTION continued........................... Page No.
B4.2 Service Linearization Calibration .................................................................... B-11
B4.3 Service Span Calibration ................................................................................ B-12
Appendix C DOWNLOADING ANALYZER FIRMWARE.
C.1
C.2
C.3
MB90 and MB120 Firmware ..................................................................................... C-1
Downloading MB90 and MB120 Firmware ............................................................... C-1
Reset MB120 Analyzer Password ............................................................................ C-3
LIST OF TABLES
TABLE NO.
1-1
2-1
4-1
4-2
5-1
TITLE
Page No.
Specifications ........................................................................................................ 1-2
Problem Solver ...................................................................................................... 2-2
Types of Performance Tests ................................................................................. 4-1
Repeatability Work Sheet ...................................................................................... 4-3
MB90 and MB120: Housing and Parts .................................................................. 5-3
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CHAPTER 1 GETTING STARTED
1.1
INTRODUCTION
This service manual contains the information needed to perform routine maintenance and
service on the Ohaus MB90&MB120 Moisture Analyzer. Familiarity with the scale’s Instruction
Manual is assumed. The contents of this manual are summarized below:
Chapter 1 Getting Started – Contains information on service facilities, tools and test
equipment, specifications, and the control functions of the scale.
Chapter 2 Troubleshooting – Contains a diagnostic guide and error code table.
Chapter 3 Maintenance Procedures – Contains preventive maintenance procedures and
disassembly, repair and replacement procedures.
Chapter 4 Final Testing – Contains a list of required test masses, an operational test,
segment display test, performance tests and adjustments.
Chapter 5 Parts Identification and Diagrams – Contains exploded views of Ranger scales
identifying all serviceable components.
Appendix A Calibration – Explains procedures for Temperature and Weight Calibration,
performed prior to using a scale, and after service.
Appendix B Software Service Tool – Explains how to use the software tool when a new Main
PCB is installed to Configure the Main PCB, enter balance serial number, and install software.
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CHAPTER 1 GETTING STARTED
1.2 Definition of Signal Warnings and Symbols.
Safety notes are marked with signal words and warning symbols. These show safety issues and
warnings. Ignoring the safety notes may lead to personal injury, damage to the instrument,
malfunctions and false results.
Signal Words
WARNING
for a hazardous situation with medium risk, possibly resulting in severe injuries or
death if not avoided.
CAUTION
for a hazardous situation with low risk, resulting in damage to the device or the
property or in loss of data, or minor or medium injuries if not avoided.
Attention
(no symbol)
for important information about the product.
Note
(no symbol)
for useful information about the product.
Warning Symbols
General Hazard
Electric Shock Hazard
Electrostatic discharge sensitive
Hot surface
1.3 Safety Precautions

AC mains powered:
- Verify that the local AC power supply is within the input voltage range printed on the
equipment’s data label. - Only connect the AC power cord to a compatible grounded
electrical outlet.

Do not position the analyzer such that it is difficult to disconnect the power cord from the
power receptacle.

This equipment is intended for indoor use and should only be operated in dry locations.
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CHAPTER 1 GETTING STARTED

Allow sufficient space between analyzer and other equipment for better air ventilations.

Operate the equipment only under ambient conditions specified in the user instructions.

Do not operate the equipment in hazardous or unstable environments.

Disconnect power from the equipment before cleaning or servicing the equipment.

Always allow the unit to have sufficient time to cool down after every heating (minimum
30 minutes).

Service should only be performed by authorized personnel.

Use electrostatic protection measures when handling the printed circuit board.

Only use original replacement parts and accessories.
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CHAPTER 1 GETTING STARTED
1.4
SERVICE FACILITIES
To service a moisture analyzer, the service area should meet the following requirements:

Should be temperature controlled and meet scale specifications for temperature
environmental requirements.

Must be free of vibrations such as fork lift trucks close by, large motors, air currents or
drafts from air conditioning/heating ducts, open windows, people walking by, fans, etc.

Area must be clean and free of excessive dust.

Work surface must be stable and level.

Scale must not be exposed to direct sunlight or radiating heat sources.

Use an approved Electro-Static Device.
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CHAPTER 1 GETTING STARTED
1.5
TOOLS AND TEST EQUIPMENT REQUIRED
The service shop should contain the following equipment:
1. Standard hand tools.
2. Digital Voltmeter (DVM): input impedance of min. 10 megohms in 1 Volt dc position.
3. Standard Electronics tool kit.
4. Soldering iron (50 watt) and solder (rosin core solder, not acid core).
5. Solder remover.
6. Ohaus Temperature Calibration Kit P/N 11113857
7. Soft, lint-free cleaning cloth
8. Anti-static bags for PCBs
9. Anti-static wrist strap and mat
1.6
TEST MASS REQUIRED
Use a 50 gram test mass with ASTM Class 1 or OIML Class E2 Tolerance.
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CHAPTER 1 GETTING STARTED
1.7 SPECIFICATIONS
TABLE 1-1. SPECIFICATIONS
Model
Capacity
MB120
MB90
120g
90g
Readability
0.001g, 0.01%
Repeatability
Results
3g sample 0.018%
3g sample 0.05%
10g sample 0.05%
10g sample 0.015%
Moisture %, Solids %, Regain %, Wt (g), Wt (custom)
Temperature Range
40℃-230℃
40℃-200℃
Drying Programs
Standard, Fast, Ramp, Step
Standard and Fast
Switch-off Criteria
Timed, Auto (30, 60, 90
seconds), Autofree mg/s,
Autofree %/s, manual
Manual, Time and Auto
Heat Source
Display Results
Halogen
% moisture,% solids,%Regain,
weight(g),temperature, time,
test ID, drying curve
Calibration
External calibration mass – 50g
Dimensions (WxHxD) (in/cm)
21x18x35
Pan Size
90mm diameter
Adjustable Feet and Level
Interface
Yes
RS232, USB host, USB device
Weight (lb/kg)
5.23
Shipping Weight (lb/kg)
8.35
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% moisture, % solids,
weight(g), temperature
and time
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CHAPTER 1 GETTING STARTED
1.7.1 Admissible Ambient Conditions: Use only in closed rooms
Indoor use only.
Altitude
Up to 4000m
Temperature range
5 ºC to 40 ºC
Maximum relative humidity 80% for temperatures up to 31
°C decreasing linearly to 50% relative humidity at 40 °C.
At least 60 minutes after connecting the instrument to the
power supply; when switched on from standby-mode, the
instrument is ready for operation immediately.
Atmospheric humidity
Warm-up time
Voltage fluctuations
Mains supply voltage fluctuations up to –15% +10% of the
nominal range
Over voltage category
II
Pollution degree
2
Power load
Max. 450 W during drying process
Current consumption
5 A or 2.5 A, according to the heating element
100 V – 120 V or 200 V – 240 V, 50/60 Hz (the voltage is
given by the heating element)
1 piece, 5 x 20 mm, T6,3 H 250 V
Power supply voltage
Power line fuse
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CHAPTER 1 GETTING STARTED
1.8 CONTROLS
5
5
1
2
3
4
1
2
3
4
Figure 1-1. MB90 & MB120 Membrane Switch and Display.
Turns On or Off display and fan.
1
2
When pressed, sends Print command.
3
When pressed, either starts or stops the drying process.
4
When pressed, performs Tare function.
5
Leveling indicator
6
Leveling Feet
Used to level the Moisture Analyzer.
6
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1.8.1
DISPLAY
The display screen is divided into sections:
1
2
3
4
Button segment
Parameters segment
Results segment
Instruction segment
User name, date and time segment
1. Test library:
2. Test results:
3. Setup:
4. Help guide:
Change parameters and create new method.
Manage test results.
Change system settings.
Method development guide and help information.
1
2
3
4
Button segment
Parameters segment
Results segment
Instruction segment
Date and time segment
Figure 1-2. MB120 and MB90 Display Screen.
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CHAPTER 1 GETTING STARTED
1.9
SETUP NAVIGATION
Press the SETUP to gain access into Setup Options.
1.9.1 SETUP SCREEN
The setup menu is activated by pressing the Setup button. The menu contains: weight and
temperature calibration, user settings, device settings, user management and system and data
management.
Figure 1-3. Setup Screen.
1.9.2
Weight and temperature calibration
1.9.2.1 Weight calibration
The Moisture Analyzer can be calibrated with an external mass of 50 grams. Calibration of the
Moisture Analyzer is not absolutely necessary for a correct moisture determination as the
measurement is relative. The balance determines the weight of the sample before and after
drying and the moisture is calculated on the basis of the ratio between wet and dry weights.
Nevertheless, you should calibrate the built-in balance under the following conditions:
- If this is stipulated by your quality assurance system (GLP, GMP, ISO 9001).
- If you suspect the analyzer has been abused.
To calibrate the analyzer, processed as follows:
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1.
Press Setup button on the main
screen.
The Setup menu appears.
Press the Weight and temperature
calibration button.
The Adjustments screen appears.
Press the Weight adjustmentexternal button
The display highlights the action
you should take.
Remove the sample pan and place
the required weight on the sample
pan, close the cover.
Follow the instructions on the
display. The display indicated if the
calibration was successful.
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CHAPTER 1 GETTING STARTED
1.9.2.2 Temperature calibration
You must have a temperature calibration kit to perform this procedure. If the Moisture Analyzer
has been recently used, allow at least 30 minutes before performing calibration.
Note: The temperature calibration kit is available as optional equipment.
Press Setup button on the main
screen.
Press Weight and temperature
calibration button.
Press Temperature calibration
button.
You are now prompted to remove
the pan handler and pan support.
Replace the pan handler and place
a temperature calibration unit on
the pan handler.
Note: The unit will not calibrate with the pan support in place.
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Press the Next and Start button to
initiate the temperature calibration
process. Follow the screen
prompts throughout the process.
The dryer unit is heated to a temperature of
100°C. You can observe the progress on the
display as the dryer temperature and count
down period are displayed. After 15 minutes,
read the thermometer through the inspection
window on the cover and enter this
temperature. Using the up/down arrow
buttons, adjust the display reading to agree
with the thermometer. Use the left/right arrow
buttons to highlight ACCEPT NEW CAL then
press the Enter button. You have 10 minutes
to make this adjustment, otherwise the
calibration is terminated.
This is a two-point adjustment (100°C and
160°C). The dryer unit now heats to the
second temperature (160°C). Adjustment of
the temperature is defined by two points.
Proceed exactly as you did for the first
temperature. After you have set the display
to agree with the thermometer, highlight
ACCEPT NEW CAL, then press the Enter
button. The display returns to ANALYZER
SETUP.
WARNING: Be careful when removing the temperature calibration kit from the
dryer unit as it can be very hot. Allow it to cool down by opening the cover before
removing.
Remove the calibration unit. Replace the pan support and pan handler in their
proper positions.
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CHAPTER 1 GETTING STARTED
1.9.2.3 Last temperature calibration result
Press Setup button on the main
screen.
The Setup menu appears.
Press Weight and temperature
calibration button.
The Adjustments screen appears.
Press the Last temperature
calibration result button.
Here you will find the last
temperature calibration result.
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1.9.3
User settings
1.9.3.1 Language
For convienence, the Moisture Analyzer is equipped with thirteen languages available on all displays.
This procedure permits the selection of any language.
Press Setup button on the main
screen.
The Setup menu appears.
Press User settings.
The User settings screen appears.
Press Language button.
Select LANGUAGE.
Note: If you select English (US) as the dialog language, the date format is
changed and appears on all records in the American notation (month/day/year).
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CHAPTER 1 GETTING STARTED
1.9.3.2 Brightness
Press Setup button on the main
screen.
The Setup menu appears.
Press User settings button.
The User settings screen appears.
Press Brightness button.
To adjust the brightness of the
screen.
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1.9.3.2 Beep
Press Setup button on the main
screen.
The Setup menu appears.
Press User settings button.
The User settings menu appears.
Press Beep button.
Make volume adjustment.
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CHAPTER 1 GETTING STARTED
1.9.4
Device settings
1.9.4.1 Date and Time
This Moisture analyzer has a communication output which allows printing the time and date on
every record. When this instrument is put into operation for the first time, you should enter the
current date and time. These settings are retained even if you disconnect your instrument from
the power supply. A built-in battery will maintain all data. To set the time and date, proceed as
follows:
Press Setup button on the main
screen
The Setup menu appears.
Press Device settings.
The Device settings menu
appears.
Press the Date-Time button.
Press the follow items to set the
date and time.
Press Back to exit.
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CHAPTER 1 GETTING STARTED
Set date format.
Press Back to exit.
Set date.
Press + and – to set correct date,
month and year.
Press Set date to save it.
Press Back to exit.
Set time format.
Press Back to exit.
Set time.
Press +and – to set correct time.
Press Set time to save it.
Press Back to exit.
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CHAPTER 1 GETTING STARTED
1.9.5 Peripherals
This Moisture Analyzer is equipped with USB and RS232 compatible interface for
communication with USB storage devices, printers and computers.
The following sections describe the hardware and software provided with the Moisture Analyzer.
Press Setup button on the main screen.
The Setup menu appears.
Press Device settings button.
The Device settings menu appears.
Press Peripherals button.
Press the following buttons to set RS232 port
when RS232 port link to printer or other
RS232 compatible device.
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Setting device port
Select the com1 for RS232, com4 for USB
Setting baud rate
Select the desired baud rates of 1200,
2400, 4800, 9600, 19200, 38400, 57600
and 115200. Default setting is 9600 Baud.
Setting data bits
Select the desired data bits of 7 or 8.
Default setting is 8.
Setting parity
Select the desired parity setting of either
NONE,EVEN or ODD. Default setting is
NONE.
Setting stop bits
Select the desired stop bits of 1 or 2.
Default setting is 1.
Setting handshake
Select the desired handshake of NONE,
Xon/Xoff. Default setting is NONE.
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CHAPTER 1 GETTING STARTED
1.9.6 Print
Press Setup button on the main screen.
The Setup menu appears.
Press Device settings button.
The Device settings menu appears.
Press Print settings button.
The Print settings menu appears.
Press Print results automatically to switch
ON or OFF.
Press Print GLP data to switch ON or OFF.
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Press the Intermediate results print interval
button.
Choose the interval seconds or minutes.
1.9.7 Company information
Press Setup button on the main screen.
The Setup menu appears.
Press Device settings button.
The Device menu appears.
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CHAPTER 1 GETTING STARTED
Press Company Information button.
The Company information screen appears.
Press each button to set the company name,
department and instrument ID.
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1.9.8
User management
Press Setup button on the main screen.
The Setup menu appears
Press User Management button.
The Users screen appears.
Press New button to create a new user.
Key in the user name and press OK to save.
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CHAPTER 1 GETTING STARTED
Set the password.
Enable the password.
Set the password.
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Set the user profile.
1.10 System and data management
Press Setup button on the main screen.
The Setup menu appears.
Press System and data management
The System and data management menu
appears.
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CHAPTER 1 GETTING STARTED
Export and Import settings and methods.
System backup and restore.
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CHAPTER 1 GETTING STARTED
Factory reset.
Software update.
Note: For the rest of the Menu navigation please kindly refer to Instruction Manual.
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CHAPTER 2 TROUBLE SHOOTING
2.1
TROUBLE SHOOTING
This section of the manual contains troubleshooting information. To isolate specific problems,
use Table 2-1, Problem Solver. Follow all directions step by step. Make certain that the work
area is clean. Handle scale components with care. Use appropriate Electro-Static Device.
2.1.1
General Procedures for Troubleshooting
1. Do the most obvious, user-level remedies.
2. Check that internal parts are clean and free of debris.
3. Use the Problem Solver (Table 2-2) to locate the symptom.
Follow the suggested remedies in the order they appear.
4. Visual Check: Examine the Load Cell for signs of bending, twisting or corrosion.
–
Clean the unit before evaluating any mechanical problems.
Remove any debris inside the Housing.
–
Check condition of Keypad and Display, Dryer Unit with protective glass,
Halogen Radiator, Reflector, Fan Grill, Leveling Feet, Rating Plate.
–
Examine the Housing for dents, bent Pan, Pan Support, Draft Shield or Heat
Shield or signs of physical abuse.
–
Replace all damaged parts. See Chapter 5 for parts list.
–
Check the cables leading to the PCBs for cuts, abrasions or other signs of
excessive wear and tear.
–
Examine the Load Cell for corrosion due to high humidity or exposure to
chemicals. A Load Cell that is even slightly bent or corroded should be replaced.
In the event of erratic or fluctuating weight readings, isolate the problem to either the
mechanical or the electronic area of the Moisture Analyzer.
If a problem arises that is not covered in this manual, contact Ohaus: www.ohaus.com.
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CHAPTER 2 TROUBLE SHOOTING
2.2
PROBLEM SOLVER
TABLE 2-1. PROBLEM SOLVER
Symptom
Possible Cause
Remedy
Moisture analyzer
Power cord not plugged in or
cannot be switched no power supply voltage.
on.
LED on Power
switch does not light
up.
Defective main fuse or
Defective power supply fuse.
Defective Power Switch or
Power Board.
Check the power cord is plugged in.
The power supply is designed for
100...240 VAC, but the drying unit
only for 110 or 230VAC. Check if
correct drying unit is installed.
Check fuses on back and on PSB.
Replace if necessary.
Replace Power Board, Power Switch.
Moisture analyzer
cannot be switched
on. LED on Power
switch does light up.
Plug in or replace cable.
Cable connections inside
instrument not plugged in or
defective.
Defective main PCB.
Replace main PCB (include SD card
and CPU).
Some buttons do not Defective keyboard.
respond.
Replace keyboard.
(A new keypad overlay is needed)
Portions of display
do not light up.
Defective display.
Replace display.
Halogen lamp does
not switch on after
"Start".
Thermal overload device has
Reset thermal overload device.
tripped.
Defective temperature controller. If resistance after resetting is >1 ohm,
replace.
Defective halogen lamp.
Replace if resistance > 20 Ohms
(check whether 100 or 230 VAC).
Temperature sensor not plugged Plug in or replace sensor.
in or defective.
Defective power supply board.
Replace power supply board.
Defective CPU board.
Replace CPU board.
Halogen lamp
switches off before
end of test.
Incorrect Halogen bulb
Check voltage rating on bulb.
Temperature rises
above 230°C.
Defective temperature sensor.
Defective Power Switch.
Defective Power board.
Defective Control Board.
Defective Main PCB.
Replace temperature sensor.
Replace Power Switch.
Replace Power Board.
Replace Control Board.
Replace Main PCB.
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CHAPTER 2 TROUBLE SHOOTING
TABLE 2-1. PROBLEM SOLVER
Symptom
Possible Cause
Remedy
Unstable weight
indication.
The air current which cools the
weighing cell is blocked.
Clean the ventilation grill.
Zero blinking
Defective Load cell
Replace load cell
2.3
TESTING
Before servicing the MB90 and MB120 Moisture Analyzer, an operational test and various
performance tests should be made to ascertain whether or not the unit meets specifications.
Turn the Moisture Analyzer on and allow it warm up for at least one hour before performing
these tests. Make sure the test area is free from drafts and the surface that the Moisture
Analyzer rests on is level and vibration free. It is recommended that an ASTM Class 1 or OIML
Class E2 Tolerance mass be used for the performance tests and adjustments.
2.3.1
Operational Test
1. Locate a suitable power source for the Moisture Analyzer. Check the voltage rating
of the Moisture Analyzer.
2. Plug the Power Cord into a suitable power source.
Note: If possible, record original customer settings so that after repairs, the
Moisture Analyzer can be returned in a satisfactory operational mode.
Note: For additional tests, see Chapter 4, Final Testing.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.1
PREVENTIVE MAINTENANCE
Ohaus moisture analyzers are precision instruments and should be carefully handled, stored in
a clean, dry, dust-free area, and cleaned periodically. Follow these precautionary steps:
–
When a moisture analyzer has had chemicals or liquids spilled on it, all exterior surfaces
should be cleaned as soon as possible with warm water on a damp cloth.
–
Do not leave a mass on the moisture analyzer when it is not in use.
–
Allow time for the moisture analyzer to stabilize after moving it from an area which is at a
different temperature than the area where it is to be operated. Allow one hour for each
5°F (2.7°C) temperature change before using the Analyzer. After temperature
stabilization, allow an additional 20 minutes after turning the unit on, for the electronics
to stabilize.
3.1.1
Preventive Maintenance Checklist
The moisture analyzer should be inspected and checked regularly, as follows:
1. Remove the Pan Handler Pan Support, and Draft Shield to inspect and clean the
area beneath the Pan.
2. Clean the outside using a damp cloth with warm water.
CAUTION
DO NOT USE CHEMICAL CLEANERS OR SOLVENTS OF ANY TYPE.
SOME CLEANERS ARE ABRASIVE AND MAY AFFECT THE FINISH.
3. Check the Power Cord for broken or damaged insulation.
4. Make a visual inspection for faulty connectors, wiring, and loose hardware.
3.2
OPENING THE MB90 AND MB120
Common hand tools are sufficient to disassemble the MB90 and MB120 moisture analyzers.
Turn the Analyzer off and unplug the power cord before you begin.
Warning: Disconnect from power supply and allow heating module to cool!
Use electrostatic protection when servicing!
Electrostatic damage is difficult to detect, because the faults it causes are not clear-cut. MOS
switching transistors with electrostatic damage have substantially higher, thermically unstable
leakage currents. As a result, the Moisture Analyzer drifts more and the display can fluctuate
similar to when there is a draft.
To avoid electrostatic damage during production, conducting floors, controlled air humidity, and
EMC mats are used. When servicing the unit it is also advisable – as soon as the instrument is
opened – to neutralize
electrostatic charges.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.2
OPENING THE MB90 AND MB120 (continued)
1. Lift the top.
2. Remove the Sample Pan, Pan Handle,
Pan Support, Draft Shield and Tray
Pan. Inspect the interior and exterior.
(See Figure 3-1.)
3. Remove the Analyzer In use cover.
4. Turn the Analyzer around, remove the
4 foots to locate the 4 screws securing
the housing in place:
Figure 3-1. MB90/120 with top open.
Analyzer foots
Bottom housing screws
Figure 3-2. Removing foots and screws from
bottom housing.
5. Holding the housing and heating
chamber in hand and carefully flip the
Analzer upwards.
6. Gently lift the Top Housing so the rear
stays in place and the front rises.
Note: Care need to be taken as there
are cables connectiions from the
heating chamber to the control board
(See Figure 3-3)
Cables attached
.
Figure 3-3. Lifting the Housing.
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CHAPTER 3 MAINTENANCE PROCEDURES
7. Remove the 3 cables, grounding wire
and 1 set of wire connected to the
control board. (See Figure 3-4.)
A
Remove cables and wire.
B
C
A- Cable to Lid sensor board
D
B- Cable to Main PCB
E
C- Cable to Main PCB
Figure 3-4. Three screws in Top Housing.
D- Wire to Heating chamber
E- Grounding cable
Note: Take note on the cable routing.
8. Lift the top housing off and set it aside.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.3 REPLACING THE POWER PCB AND POWER SWITCH
1. Flip the Analyzer around and locate the Power PCB compartment.
2. Remove the Analyzer two back foots.
Remove 2 back foots.
3. Remove the 4 screws securing the power board compartment.
Remove 4 compartment screws.
4. Below show the Analyzer Power Switch and Power Board.
A- Power Board
B- Power Switch
A
B
Note: Take note on the cable and wire routing.
5. Replacing the Power Board PCB by removing the below cables from
the PCB. Locate the two screws securing the PCB and remove the
screws (top right, bottom left).
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Screw
Remove cables from Power Board
PCB
Screw
6. Remove the Power Board from compartment.
7. Replacing the Power Switch PCB by removing two cables from the
PCB. Locate and remove the 4 screws at 4 corners of the PCB which
securing the PCB in the compartment.
Removing cables from Power Switch PCB.
8. Remove the Power Switch from the compartment.
Note: When there is power cycling the Power Switch PCB the green
LED will light up. If the LED does not light up possible defective PCB
or main fuse in the AC plug is open circuit and need to be replaced.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.4
REPLACING THE AC PLUG FUSE.
1. Locate the main fuse compartment which is located in the AC plug at
the back of the Analyzer.
2. Replace an open circuit fuse.
3.5
REPLACING THE AC PLUG.
1. Open the Analyzer Power Compartment (Refer to 3.4).
2. Remove the two cables connected from the AC Plug to the
Power Board and the Grounding wire to the Analyzer base.
Cable tie.
Remove cables and Grounding Wire.
Note: Take note on the two cables which are tied together as
shown above make sure you do the same when replacing the
AC Plug. Both AC Plug and cable tie is as a kit as below along
with others cable sets.
30246957
SP, Base Cable Kit, MB90 MB120
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CHAPTER 3 MAINTENANCE PROCEDURES
3. Locate and remove the two screws securing the AC plug to the housing.
4. Remove and replace the AC Plug by shifting the plug upwards.
3.6
REPLACING THE CONTROL BOARD.
1.
Open the Analyzer (Refer to 3.2)
2.
Detach the Top Housing.
3.
Locate the Control Board which is above the load cell.
4.
Locate the 5 screws securing the Control Board to the housing and detach the load
cell cable and cable from Control Board to Power Board.
Cable from Control
Board to Power Board.
Load cell cable
5.
Remove and replace the Control Board.
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CHAPTER 3 MAINTENANCE PROCEDURES
Note: Software upload via Service and Repair Tools is needed when replacing the
Control Board.
3.7
REPLACING THE MAIN PCB.
1.
Open the Analyzer (Refer to 3.2).
2.
The Main PCB is located at the Top Housing.
Cables to Control Board.
Cables to
Keyboard.
3.
Remove the cables from Main PCB to Control Board and cable to key board.
4.
Locate and remove the 4 screws that secure the Main PCB to housing.
5.
Remove and replace the Main PCB.
Note: Software upload via Service and Repair Tools is needed when replacing the
Main Board. The new Main board spare part includes the Main PCB, CPU (with WinCE
license sticker) and SD Card.
CPU
Main PCB
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SD
WinCE license
sticker
MB90 and MB120 Service Manual
CHAPTER 3 MAINTENANCE PROCEDURES
3.8
REPLACING THE LOAD CELL.
1.
Open the Analyzer (Refer to 3.2)
2.
Detach the Top Housing.
3.
Locate the Load Cell.
4.
Remove the Load Cell metal plate by removing the 4 screws securing the plate.
Load cell metal
plate
Load cell metal cover
Screws holding the Load Cell metal
plate.
5.
6.
After Load Cell metal plate
removed.
Lift up the Load Cell metal cover you will see the Load Cell kit.
Remove the Load Cell cable from the Main PCB and remove the 6 screws securing
the Load Cell kit.
Remove load cell cable
from Main PCB
Remove 6 screws
7.
Remove and replace the Load Cell kit.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.9
REPLACING THE LOAD CELL ACCESSORY KIT.
The load cell accessory kit consist of the below.
Load cell rubber ring
Moisture adsorb material
Moisture adsord material:
1.
After removing the Load cell kit from its compartment (Refer to 3.9) you will see the
moisture absorb material (as shown above and below pictures).
Moisture adsorb material
2.
Discard and replace this Moisture adsorb material when is in bad condition.
Note: The purpose of this Moisture adsorbs material is to adsorb moisture content in
the load cell compartment to protect the load cell performance. After replacing this
material it is advised to let the material set for a day before performing any weight
calibration to the Analyzer.
Load cell rubber ring:
1.
Open the Analyzer (Refer to 3.2)
2.
Detach the Top Housing.
3.
Locate the Load Cell.
4.
Open the load cell (Refer to 3.9)
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CHAPTER 3 MAINTENANCE PROCEDURES
5.
You will able to locate the rubber ring on the load cell kit as shown in below picture.
Load cell rubber ring
6.
The rubber ring needs to be replaced if ware and tare is detected.
Note: DO NOT Stress the rubber ring when inserting into the load cell kit.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10 REPLACING THE HEATING CHAMBER PARTS
3.10.1 Opening the Heating Chamber Compartment.
1.
Lift up the heating chamber.
2.
Remove the Sample Pan, Pan Handle, Pan Support, Draft Shield and Tray Pan (3.2)
3.
Remove the chamber metal lid cover and plastic lid cover.
4.
After removing the compartment heating chamber components expose as below.
1. Thermal overload.
2. Temperature sensor.
3. Halogen Lamp.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.1.1 Replacing the Temperature sensor.
1. Remove the temperature wire from its protective sleeve.
2. Detach the wire connection as show below.
3.
Remove the two screws holding the temperature sensor in position.
4.
Remove and replace the temperature sensor when necessary.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.1.2
Testing the Temperature Sensor and Cable
1.
Remove the temperature sensor cable from its protective sleeve.
2.
Disconnect the cable and Connect probes to the Temperature Sensor Cable’s
3.
Measure resistance: it should be approximately 1,000 Ω.
4.
Open and close the Top Housing while checking for an intermittent cable problem.
Readings should not fluctuate during this test.
5.
If resistance and flex tests (3 & 4 above) are OK, the Temperature Sensor is good.
If not, replace the cable or sensor.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.1.3
Replacing the Halogen Lamp.
1. Open the lid. (3.10.1)
2. Remove the chamber glass by following the below steps.
- Gently separate the two metal clips which securing the chamber glass in position.
3. Remove the temperature sensor. (3.10.1.1)
4. Remove the two screws securing the temperature sensor holder in place.
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CHAPTER 3 MAINTENANCE PROCEDURES
5. Use both fore fingers to spread the clamping spring to the left and right and at the
same time use both thumbs to lift the Halogen lamp carefully upward out of the
clamping springs.
6. Remove and replace a defective halogen lamp.
Note:
The two ends of the Halogen lamp must not be bent toward or away from each other;
otherwise, the glass tube will break
Typical lift span of a halogen lamp is approximately 5000 heating hours.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.1.4
Replacing the Thermal Overload.
1. Open the lid (3.11.1).
2. Remove the Temperature sensor (3.11.1.1)
3. Remove the halogen lamp if necessary (3.11.1.3)
4. Remove the two wires connected to the Thermal overload.
5. Use a wrench to loosen the nut which securing the Thermal overload in place.
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CHAPTER 3 MAINTENANCE PROCEDURES
6. After removing the nut glide the Thermal Overload from the chamber housing.
7. Remove and replace the Thermal Overload.
Note:
During this step care is needed to avoid breaking the Halogen lamp. (if the halogen
lamp still attached).
3.10.1.5
Installing the Thermal Overload.
1. Install the component by reversing steps mention in 3.11.1.4.
2. Install back the Thermal overload following the below parts install sequence.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.1.6
1.
Testing the Thermal Overload.
Performing a continuity test on the Thermal Overload; with power to the unit off, use
an ohm meter to measure resistance between the devise's poles. Resistance should be
zero Ω. If so, the devise is in good working condition if not continue to step 2.
2.
Press the devise's reset button. Then re-test.
3.
If test fails, replace the components.
4.
Reassemble the Heating Unit.
5.
Perform a Temperature Calibration. (See Appendix A.2)
6.
Conduct Performance Tests.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.2 Replacing Top Housing Components.
3.10.2.1 Removing the top housing cast iron plate.
1.
Open the Analyzer and remove the Main PCB (3.8)
2.
Remove the top housing cast iron plate by removing the 6 screws as shown below.
3.
You will see the below components.
- LCD Display
- Keyboard
- Fan
- Lid sensor board
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.2.2
Replacing the Fan.
1. Open the Analyzer and remove the Main PCB (3.8)
2. Remove the housing cast iron plate (3.11.2)
3. Locate the Fan.
4. Remove the Fan cable connected to the Lid sensor board.
5. Remove and replace the Fan.
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CHAPTER 3 MAINTENANCE PROCEDURES
3.10.2.3
Replacing the Lid sensor board.
1. Open the Analyzer and remove the Main PCB (3.8)
2. Remove the housing cast iron plate (3.11.2)
3. Locate the Lid sensor board.
4. Remove cable from Fan and to temperature sensor, remove the 3 screws holding the
board is place.
5. Remove and replace the Lid sensor board.
3.10.2.4
Replacing the LCD display.
1. Open the Analyzer and remove the Main PCB (3.8)
2. Remove the housing cast iron plate (3.11.2)
3. Locate the LCD display.
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4. Use a broad blade, such as a wide X-Acto™ knife, to remove the label. Clean the
glue residue from the Housing surface.
5. Remove and replace the LCD display.
6. Then carefully place the new label where the old one was.
3.10.2.5
Replacing the Keyboard.
1. Open the Analyzer and remove the Main PCB (3.8)
2. Remove the housing cast iron plate (3.11.2)
3. Locate the Keyboard.
4. Use a broad blade, such as a wide X-Acto™ knife, to remove the label. Clean the
glue residue from the Housing surface.
5. Remove and replace the Keyboard.
6. Then carefully place the new label where the old one was.
3.10.2.5
Replacing the Label.
1. Use a broad blade, such as a wide X-Acto™ knife, to remove the label. Clean the
glue residue from the Housing surface. Then carefully place the new label where the
old one was.
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CHAPTER 4 FINAL TESTING
4.1
FINAL TESTING
Before servicing the MB90 or MB120 Moisture Analyzer, an operational test and various
performance tests should be done to determine if the unit meets specifications. Turn the
Moisture Analyzer on and allow it warm up for at least one hour before performing these tests.
NOTE:
Make sure the test area is free from drafts and the surface the Analyzer rests on
is level and vibration-free. An ASTM Class 1, or OIML Class E2 Tolerance mass
should be used for the performance tests and adjustments.
4.2
Operational Test
Check the Analyzer’s voltage rating, and plug the Power Cord into a suitable power source.
4.3
LCD Display Test
Turn the Moisture Analyzer on, and ensure the LCD are display normal with no missing
segment.
4.4 Performance Tests
Accurate performance is determined by a series of three performance tests: Precision, OffCenter Load and Centered Load. The displayed readings are compared with the tolerances
listed in Table 4-1. Before starting the performance tests, level the Moisture Analyzer.
TABLE 4-1. TYPES OF PERFORMANCE TESTS & TOLERANCES
PERFORMANCE TEST
Tolerance: MB90
Tolerance: MB120
Precision (Std Deviation)
±0.2g
±0.2g
Repeatability (Std Dev)
0.18% (3g sample)
0.02% (10g sample)
0.05% (3g sample)
0.015% (10g sample)
Note: Ideal test sample e.g. 5% +/-1% NaCI solution is required for moisture repeatability test.
The following performance tests are used to evaluate the Moisture Analyzer operation before
and after repairs. Each Moisture Analyzer tested must meet the requirements specified in each
test as well as the specifications listed in Table 1-1. A Moisture Analyzer which passes each of
these three tests meets the manufacturing specifications.
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CHAPTER 4 FINAL TESTING
4.4.1
Precision Test
In Analyzer specifications, the term Precision means the Standard Deviation of a set of similar
weight readings. To determine if an Analyzer meets the calculated Standard Deviation value in
the Specification Table 4-1, perform the following test:
1. Tare the Analyzer. The reading on the display should be 0.000g.
2. Place a 50g mass on the center of the sample pan. Observe and record the reading
when the stable indicator comes on.
3. Remove the mass. The reading should return to 0.000 within the published
tolerance when the stable indicator is on.
4. Repeat this test for ten readings. If the standard deviation of the readings is less than
the indicated tolerance, the Analyzer passes the Precision Test.
CAUTION: Remove the mass from the pan after testing.
Adjustment
If the deviation for any set of readings (using the same mass placed on the center of the pan) is
greater than the indicated tolerance, the Moisture Analyzer does not meet the Precision Test
specification. Inspect and correct the following areas:
1. Check for mechanical obstructions: any foreign object touching any part of the
moving pan linkage assembly will cause the Analyzer to fail the Precision Test.
Inspect and correct as necessary.
2. An error in the Off-Center Load Test can affect the results of the Precision Test.
Inspect and correct if necessary. (See Off-Center Load Test.)
3. Foreign material or debris between the pan and the base will cause the Analyzer to
fail the test.
4. Vibrations, drafts or a non-level surface can cause failures.
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CHAPTER 4 FINAL TESTING
4.4.2
Repeatability Test
Repeatability is the Standard Deviation of a set of similar readings.
Requirements:
– To perform this test, identical samples must be used for all readings.
–
The test sample should be approximately 50 grams.
–
Wear gloves when handling the sample.
Before starting a repeatability test, set up the instrument as follows:
TEST PROCEDURE:
1. Zero the instrument.
2. Using a test sample of approximately 50 grams, place the sample on the center of
platform. Record the reading on the worksheet provided.
3. Remove the sample from the platform.
4. Repeat this test starting at Step 1 until you record a total of ten readings
Fill in the worksheet (Table 4-2) with the ten (10) readings.
TABLE 4-2. REPEATABILITY WORKSHEET
n
Reading
Delta = Reading – Mean
Delta x Delta
1
2
3
4
5
6
7
8
9
10
n = number of Reading
Mean = Sum of readings / 10
Delta = Reading – Mean
Standard Deviation = Square Root of (sum of (Delta x Delta) / 9)
5. Add the ten readings and divide the total by 10 to find the Mean (average).
6. Mean = (Reading 1 + Reading 2 + Reading 3 + Reading 4 + Reading 5
7. + Reading 6 + Reading 7+ Reading 8 + Reading 9 + Reading 10) / 10
Mean =________
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4.4.2
Repeatability Test
8. Calculate the Delta for each reading and record it in the work sheet.
Delta = Reading – Mean
9. Calculate the Delta x Delta for each reading and record in worksheet.
10. Add the ten Delta x Delta values and divide by 9
11. Calculate the Standard Deviation by applying the square root of the result from step 8.
Standard Deviation =___________
Note: If the Analyzer does not meet specifications, move it to a suitable location, ensure
that it is level, and try again. If it still does not meet specifications, calibrate the unit and
try again. (See Appendix A for Calibration.)
4.4.3
Linearity Test
This test is used to determine the linearity of the unit throughout its operating range.
The masses used to perform this test can be utility masses.
Note: Due to the use of relative weighing and limited use of the weighing range in moisture
analysis, linearity performance is not critical.
Linearity Test Mass
– Reference Mass: 10g
PERFORMANCE
TEST
Load 1
Load 2
Load 3
MB90
MB120
10g
40g
80g
10g
40g
100g
NOTE:
All masses are nominal values. Be certain to use the same reference mass throughout
the procedure.
1. Place the reference mass on the pan, record the weight and remove.
2. Place Load 1 on the pan and press TARE.
3. Place the test mass on the pan, record the weight and remove.
4. Place Load 2 on the pan and press TARE.
5. Place the test mass on the pan, record the weight and remove.
6. Place Load 3 on the pan and press TARE.
7. Place the test mass on the pan and record the weight.
8. The difference in the weights of the test mass should be within the Linearity
tolerance in Table 1-1. If not, calibrate (see Appendix A.1) and repeat the test.
9. If the unit remains out of tolerance, the Load Cell may need to be replaced.
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CHAPTER 5 PARTS IDENTIFICATION & DIAGRAMS
This section of the manual contains exploded views for the Ranger Series scales. The exploded
view drawings are designed to identify the parts which can be serviced on the scale in the field.
Note that not all parts identified are available as spare parts – for current parts lists contact your
local Ohaus distributor, or www.ohaus.com.
NOTE:
In all cases where a part is replaced, the scale must be thoroughly checked after
the replacement is made. The scale MUST meet the parameters of all applicable
specifications in this manual.
If further technical information is needed, please contact your local Ohaus distributor, or:
Ohaus Corporation
www.ohaus.com
7 Campus Drive, Suite 310
Parsippany, NJ 07054 USA
Tel: 973-377-9000
In the United States call toll free, 800-526-0659 between 8:00 a.m. and 6:00 p.m. EST.
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CHAPTER 5 PARTS IDENTIFICATION & DIAGRAMS
5.1
MB90 & MB120: HOUSING AND PARTS
Figure 5-1. MB90 & MB120: Housing and Parts.
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CHAPTER 5 PARTS IDENTIFICATION & DIAGRAMS
5.1
MB90 & MB120: HOUSING AND PARTS
TABLE 5.1: MB90 & MB120 HOUSING AND PARTS.
Drawing
Item
Description
1
Hinge
2
Lid
3
Thermal Overload
4
Halogen Bulb
5
Glass
6
Pan Holder
7
Pan support
8
Wind Ring
9
Tray
10
Air Channel Kit
13
Main Board
14
Key Board
15
LCD
16
17
Overlay
Load Cell
18
Load Cell Acc Kit
19
Foot
20
Base Cable Kit
21
Bottom Housing
22
Power Switch
23
Power Board
24
Control Board
25
Heater Cable
26
Top Housing
27
Lid Sensor Board
28
Fan
29
Hardware Kit
30
Lid Cover
31
Temperature Sensor
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APPENDIX A STANDARD CALIBRATION
APPENDIX A.
Weight and temperature calibration
A.1 Weight Calibration
The Moisture Analyzer can be calibrated with an external mass of 50 grams. Calibration of the
Moisture Analyzer is not absolutely necessary for a correct moisture determination as the
measurement is relative. The balance determines the weight of the sample before and after
drying and the moisture is calculated on the basis of the ratio between wet and dry weights.
Nevertheless, you should calibrate the built-in balance under the following conditions:
- If this is stipulated by your quality assurance system (GLP, GMP, ISO 9001).
- If you suspect the analyzer has been abused.
Note: Do not cover the lid during any weight calibration
To calibrate the analyzer, proceed as
follows:
Press the Setup button to access the
Setup menu.
Press Back to return to Home screen.
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APPENDIX A STANDARD CALIBRATION
Press the Weight and temperature calibration button to access calibration menu.
Press Back to return to previous step.
Press the Weight adjustment-external button
The display highlights the action you should take.
Follow the instructions on the display. Remove the sample pan. Place the required weight on
the sample pan and remove the weigh from pan.
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MB35 Moisture Analyzer Service Manual
APPENDIX A STANDARD CALIBRATION
The display indicates if the calibration was successful.
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APPENDIX A STANDARD CALIBRATION
A.2 Temperature Calibration.
You must have a temperature calibration kit to perform this procedure. If the Moisture Analyzer
has been recently used, allow at least 30 minutes before performing calibration.
Note: The temperature calibration kit (11113857) is available as optional equipment.
Press Setup button to access the calibration menu.
Press Back to return to Home screen.
Press Weight and temperature calibration button.
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MB35 Moisture Analyzer Service Manual
APPENDIX A STANDARD CALIBRATION
Press Back to return to previous screen.
Press Exit to return to Home screen.
Press Temperature calibration button.
You are now prompted to remove the pan support. Place a temperature calibration unit and
close the upper housing.
Press the Start to initiate the temperature calibration process. Follow the screen prompts
throughout the process.
The dryer unit is heated to a temperature of 100°C. You can observe the progress on the
display as the dryer temperature and count down period are displayed. After 15 minutes, read
the thermometer through the inspection window on the cover and enter this temperature. Adjust
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APPENDIX A STANDARD CALIBRATION
the display reading to agree with the thermometer, and then press the Enter button. You have
15 minutes to make this adjustment, otherwise the calibration is terminated.
This is a two-point adjustment (100°C and 160°C). The dryer unit now heats to the second
temperature (160°C). Adjustment of the temperature is defined by two points. Proceed exactly
as you did for the first temperature. After you have set the display to agree with the
thermometer, then press the Enter button.
CAUTION: Danger of burns.
Be careful when removing the temperature calibration unit from the dryer unit as it can
be very hot. Allow it to cool down by opening the cover before removing.
Remove the calibration unit. Replace the pan support in its proper positions.
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MB35 Moisture Analyzer Service Manual
APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
APPENDIX B. SOFTWARE SERVICE TOOL INSTRUCTIONS
WARNING: DO NOT USE THE COMPORT NAME 'SERVICE' AT THE BACK OF THE
ANALYZER WHEN CONNECTING THE ANALYZER TO THE SERVICE AND REPAIR
TOOLS.
For the latest software service tool version and instructions on how to use it, please follow below
steps:
1. Go to http://dmx.ohaus.com and log in with your username and password.
2. Go to View by product.
3. Open the folder ‘Service Software’.
4. Open sub folder ‘Service’.
5. Open sub folder ‘Service Tools’.
6. Download tool and database file.
7. Open sub folder ‘Service Manual’.
Note: Under 'Product Selection' kindly select MB90/120 MOISTURE.
MB90/120 Moisture is available in Ohaus Repair and Service Tools V2.1.2.6 above.
Note: Kindly download and use the update Service.mdb file from DMX.
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
After selecting 'MB90/120 MOISTURE' under 'Product Selection' you will be able to see the
below 'Function Selection' which support MB90/120 Moisture Analyzer.
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.1 Restore EEPROM
Restore EEPROM allows authorize service person to upload and restore the scale
data.
Information such as below will need to provide to OHAUS in order to obtain the scale eif file.
1. Analyzer Model Number.
2. Analyzer Serial Number.
3. Analyzer Load Cell Serial Number.
Once Restore EEPROM is selected Write Image File will appear on screen Click Next to allow
you to set the Com Port Configuration.
After completing the Comport configuration click Next. You will come to Write Image File
page as shown below.
Fill in the below and click Next to complete the Write Image File process.
1.
2.
3.
4.
5.
Analyzer Serial Number.
Analyzer Load Cell Serial Number.
Model Number.
Point to the Analyzer and Load Cell image file (eif files) provided by OHAUS.
Click Next to complete the Write Image File process.
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.2 Replace Main PCB.
If replacing a new Main PCB to the Analyzer one will need to perform the 'Replace Main PCB'
function.
Note: Kindly take note At the right hand remark in RED with Picture as shown below before
proceeding.
After powering up an Analyzer with a new PC Board, you will see the display screen as below
indicating no software is installed. You will need to upload the software to a USB drve first
before performing this function. Updated firmware is availabe on OH DMX.
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
Information such as below will need to provide to OHAUS in order to obtain the scale eif file.
1. Analyzer Model Number.
2. Analyzer Serial Number.
3. Analyzer Load Cell Serial Number.
Once 'Replace Main PCB' is selected the Com Port Configuration option will appears,
complete the configuration and click Next. You will see the bellow window.
Fill in the below and click Next.
1.
2.
3.
4.
5.
Analyzer Serial Number.
Analyzer Load Cell Serial Number.
Model Number.
Point to the Analyzer and Load Cell image file (eif files) provided by OHAUS.
Click Next to complete the Write Image File process.
Note: After completing the above information when you click 'Next' you will hear a beep sound
from the Analyzer and the Analyzer will display the below message. Wait until the download
process is completed then ONLY PRESS the 'OK' button on the Analyzer display in order for
the Analyzer to re-boot (a normal re-boot would take approximately 20-30 sec).
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.3 Replace Control Board.
If replacing a new Control Board to the Analyzer one will need to perform the 'Replace Control
Board' function.
Note: Kindly take note at the right hand remark in RED with Picture as shown below before
proceeding.
The new Control Board will be pre-loaded with the Drying firmware but to make sure the
firmware is updated one needs to upload the Analyzer firmware via the USB before
performing this function. Updated firmware is available in OH DMX. Kindly refer to Appendix
C on how to install MB90 and MB120 firmware.
Information such as below will need to provide to OHAUS in order to obtain the scale eif file.
1. Analyzer Model Number.
2. Analyzer Serial Number.
3. Analyzer Load Cell Serial Number.
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
Once 'Replace Control Board' is selected the Com Port Configuration option will appear,
complete the configuration and click Next. You will see the bellow window.
Fill in the below and click Next.
1.
2.
3.
4.
5.
Scale Serial Number.
Model number.
Load Cell Serial Number.
Point to the Analyzer and load cell image file provided by OHAUS.
Click Next to complete the Replace Control Board process.
Note: After completing the information above and clicking Next, you will hear a beep from the
Analyzer and the Analyzer will display the message below. Wait until the download process is
completed then ONLY PRESS the 'OK' button on the Analyzer display in order for the
Analyzer to re-boot (a normal re-boot takes about 20-30 sec.).
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.4 Diagnostics.
Diagnostic act as a communication window between scale and Service and Repair Tools.
Once 'Diagnostic' is selected the Com Port Configuration option will appear. Complete the
configuration and click Next. You will see the bellow window.
MB90/120 Diagnostics consists the below function.
1. Ramp - A to D conversion information.
2. Linearization- Service Linearization (performing Service Linearization).
3. Span- Service Span (performing Service Span Calibration)
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
4. Key in scale command and press 'Send'. The right side window will show the response
to the command.
5. MB90 and MB120 support the below print command.
B.4.1 Ramp ON
Select 'Ramp ON' the right hand window will show the A to D conversion signal from Load cell
to Main PCB. Press again to terminate the function.
The Ramp Value is not important as long as the value is stable and responsive to load on the
sample pan as shown below.
Stable Ramp value
Responsive Ramp value when
load indicated on weighing pan
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.4.2 Linearization (Service Linearization Calibration)
Selecting this function will allow the Analyzer to perform the Service Linearization calibration.
Follow instruction on the Analyzer display screen when selecting this function.
During Service Linearity Calibration below test weight is required.
Model
Test weight
MB90
25g and 50g
MB120
50g and 100g
Note: Do not cover the lid during any weight calibration
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APPENDIX B SOFTWARE SERVICE TOOL INSTRUCTIONS
B.4.3 Span (Service Span Calibration)
Selecting this function will allow the Analyzer to perform the Service Span Calibration. Follow
instruction on the Analyzer display screen when selecting this function.
During Service Span Calibration below test weight is required.
Model
Test weight
MB90
50g
MB120
100g
Note: Do not cover the lid during any weight calibration
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APPENDIX C SOFTWARE SERVICE TOOL INSTRUCTIONS
APPENDIX C. DOWNLOADING ANALYZER FIRMWARE
C1. MB90_MB120 Firmware
MB90 and MB120 Firmware can be uploaded from OHAUS support website (DMX) Both
Analyzers used the same firmware THEREFORE factory configuration will define the
model of the Analyzer.
Since the firmware operated under MB90 and MB120 are different from the rest of
OHAUS products there are no MOT or BIN files uploaded for this products.
C2. Downloading MB90 and MB120 Firmware.
1. Obtain Analyzer firmware from DMX as below.
Under MB90 and MB120 Moisture Analyzer folderServiceService Tools.
You will locate the file name 'MB90_120_SR1_xx.zip' files on the right window. Download the
file and un-zip the file into an empty USB thumb drive. After un-zipping the file drag all the files
inside folder ' MB90_120_SR1-xx' into your thumb drive (you will have total 9 files).
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APPENDIX C SOFTWARE SERVICE TOOL INSTRUCTIONS
2. Insert the thumb drive into either one of the USB Host located at the back of the
Analyzer.
3. Switch ON the power, during power up the Analyzer will indicate the presence of
the thumb drive and starts to locate the Autorun file from the thumb drive and start
the firmware upload.
4. The firmware upload will not carry on if the below occurs.
- All the 9 files stated above are still in the zipped folder.
- Analyzer will skip the firmware upload if its detected the files in the thumb drive is older
version then the firmware uploaded in the Main PCB and Control Board.
5. The whole process will take around 30 sec to complete and during the process the
Analyzer will have a onetime Auto Boot.
6. When you see the below screen only you remove the thumb drive and RE-BOOT the
Analyzer to complete the firmware upload.
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APPENDIX C SOFTWARE SERVICE TOOL INSTRUCTIONS
C3. Reset the Analyzer Password.
If the user forgot the Administration/Supervisor/Operator password they can re-set MB120 by
following the below instruction.
1. Obtain MB120 Password Reset from DMX as below.
Under MB90 and MB120 Moisture Analyzer folderUserSoftware.
You will locate the file name 'MB120 Password Reset.zip' files on the right window. Download
the file and un-zip the file into an empty USB thumb drive. After un-zipping the file drag all the
files inside folder ' MB90_120 Password Reset' into your thumb drive (you will have total 3 files).
2. Insert the thumb drive into either one of the USB Host located at the back of the
Analyzer.
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APPENDIX C SOFTWARE SERVICE TOOL INSTRUCTIONS
3. Switch ON the power, during power up the Analyzer will indicate the presence of
the thumb drive and starts to locate the Autorun file from the thumb drive and start
the password reset process.
4. Once the process is completed you will see the below on Analyzer Screen.
5. Remove the thump drive and RE-BOOT. The Analyzer after rebooting will then
shown the screen below after a successful password reset.
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APPENDIX C SOFTWARE SERVICE TOOL INSTRUCTIONS
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*30284484*
P/N 30284484A SERVICE MANUAL: MB90 And MB120 MOISTURE ANALYZER