TECHNICAL DOCUMENTATION

Address Mettler-Toledo AG, CH-8606 Greifensee

Telephone 01-944 22 11
Telefax 01-944 30 80
Telex 826150 mig ch

Service manual

METTLER
BD balances

Current status of the service manual, see page 14

Bild
0.0
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g

*P709116*

© Mettler-Toledo AG 1992 ME-709116 Printed in Switzerland 9211/8.12

Edition: November 1992
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BD balances Contents

Contents Page

1. General information ........................................................................................................................ 3

1.1 Technical training .............................................................................................................................. 3
1.2 How to use this documentation efficiently ......................................................................................... 3

2. Spare parts ...................................................................................................................................... 4

2.1 Exploded view diagram ..................................................................................................................... 4
2.2 Spare parts list .................................................................................................................................. 5
2.3 Service tools ..................................................................................................................................... 5
2.4 Packaging ......................................................................................................................................... 5
2.5 AC adapters ...................................................................................................................................... 5

3. Checking .......................................................................................................................................... 6
3.1 Function check .................................................................................................................................. 6
3.2 Repairs ............................................................................................................................................. 6
3.3 Cleaning ............................................................................................................................................ 6
3.4 Settings and adjustment ................................................................................................................... 6
3.5 Final worksteps ................................................................................................................................. 6

4. Service interface ............................................................................................................................. 7

4.1 Preparing the service interface ......................................................................................................... 7
4.2 Installing/removing the service interface ........................................................................................... 7
4.3 Service interface menu ..................................................................................................................... 7

5. Troubleshooting ............................................................................................................................. 8

6. Repairs ............................................................................................................................................. 9
6.1 Opening and closing the balance ..................................................................................................... 9
6.2 Changing the housing ....................................................................................................................... 9
6.3 Replacing the sensor ........................................................................................................................ 9
6.4 Replacing the board .......................................................................................................................... 10

7. Settings and adjustment ................................................................................................................ 11

7.1 Adjusting the overload protection ..................................................................................................... 11
7.2 Drift compensation ............................................................................................................................ 11
7.3 Linearity adjustment .......................................................................................................................... 12

8. Technical data and adjustment tolerances .................................................................................. 13

8.1 Weighing range, readability, cornerload and overload ..................................................................... 13
8.2 Linearity, calibration weight and temperature compensation ............................................................ 13

9. Service bulletins ............................................................................................................................. 14

Service manual ME-709116 06/92 -1-

Contents BD balances

-2- Service manual ME-709116 06/92

BD balances General information

1. General information

1.1 Technical training

BD balances are simple user-friendly instruments that are easy to service. Instruction courses for these balances
will not be held by METTLER Technical Training.
However, with this service manual and the operating instructions you will be in a position to acquire the necessary
knowledge by self-study.
For this you need a BD balance with interface and operating instructions, this service manual and 1/2
day.

Procedure
• Familiarize yourself with the construction and functioning of the BD balances using the operating instructions.
• Go through the checklists, see section 3 of this service manual.
• Disassemble balance, see section 6 of this service manual.
• Perform adjustment, see section 7 of this service manual.

1.2 How to use this documentation efficiently

Exploded view diagram and spare parts list

The exploded view diagram services as an assembly and orientation aid and to determine the spare part
numbers.
Order spare parts using the details given in the spare parts list. This list specifies the order numbers of those parts
itemized in the exploded view diagram.

Service manual ME-709116 06/92 -3-

Spare parts BD balances

2. Spare parts

2.1 Exploded view diagram

ME
TTLE
R

ME
TTLE
R

4
1
2

-4- Service manual ME-709116 06/92

BD balances Spare parts

2.2 Spare parts list

Item Designation ME No. ME No. ME No. ME No. ME No.

BD202 BD601 BD601L BD1201 BD6000

1 Housing 590201 590202 590204 590202 590203

2 Battery holder 590112 590112 590112 590112 590112

3 Battery compartment
cover 590115 590115 590115 590115 590115

4 Sensor (cell) 590205 590206 590208 590210 590207

5 Board 590209 590209 590209 590209 590209

6 Weighing pan 590118 590113 590113 590114 590211

7 Interface 590102 590102 590102 590102 590102

2.3 Service tools

Interface ME-590102

Allen key 3/32" enclosed with sensor

2.4 Packaging

Transport bag ME-590117

2.5 AC adapters

Accu Pac ME-590103

AC adapter US 110 V/120 V ME-590108

AC adapter EURO 220 V/240 V ME-590109

AC adapter UK 240 V ME-590110

AC adapter AUS 220 V/240 V ME-590111

Service manual ME-709116 06/92 -5-

Checking BD balances

3. Checking

3.1 Function check

• Check keys
• Check reproducibility
• Test hysteresis
• Test cornerload
• Test linearity
• Test overload
• Check plug-in connections

3.2 Repairs

Repair work consists of the replacement of damaged or faulty parts available as spare parts, see section 6.

Note
Before starting the replacement work, make a note of the existing menu settings so that they can be reset on
completion of the service work.

3.3 Cleaning

Cleaning with a damp cloth and the usual household cleaners, never use nitro-containing solvents.

3.4 Settings and adjustment

After replacement of the sensor (cell), the overload screw must be adjusted.
Adjustment comprises the linearity adjustment and drift compensation. You will find a detailed description in
section 7.

3.5 Final worksteps

• Calibration, see operating instructions.

• Reset previous menu settings.
• Reattach peripherals.

-6- Service manual ME-709116 06/92

BD balances Service interface

4. Service interface

The RS-232 interface in the optional equipment is also used as a service interface, but it requires special
preparation. The customer interface can not be used for servicing purposes.

4.1 Preparing the service interface

To be able to use the RS-232 interface as a service

interface, the jumper (1) must be soldered in over R7.

4.2 Installing/removing the service interface

The installation/removal of the service interface is described in the installation instructions ME-709111.

Procedure
• Remove customer interface if fitted.
• Install service interface.
• Perform adjustment.
• Remove service interface.
• Reinstall customer interface.

4.3 Service interface menu

The menu of the service interface also includes menu options SE.0 for the linearity adjustment and SE.1 for the
drift compensation.
• Entry into the menu: Press and hold CAL/MENU key until MENU is displayed.
• Select menu option "SE.0" or "SE.1": Press Z key repeatedly until the desired display appears.
• Performing the adjustment, see section 7.

Service manual ME-709116 06/92 -7-

Troubleshooting BD balances

5. Troubleshooting

Fault Cause Rectification

Error 9 Fault in EEPROM Replace board

Balance can not be switched on No line voltage Attach balance to power supply
Battery discharged Replace battery
AC adapter faulty Replace AC adapter
Accu Pac faulty Replace Accu Pac
Board faulty Replace board
Sensor (cell) faulty Replace sensor

Balance can not be switched off Board faulty Replace board

Taring not possible Board faulty Replace board

Display does not light up completely Board faulty Replace board

Sensor does not equilibrate Overload screw out of Adjust overload screw
adjustment
Sensor faulty Replace sensor
Board faulty Replace board

Overload >150 % full load Overload screw out of Adjust overload screw
adjustment
Sensor faulty Replace sensor
Board faulty Replace board

Abrupt change in display Powerful drafts

Severe vibrations
Severe power line
disturbances
Board faulty Replace board
Sensor faulty Replace sensor

Hysteresis Sensor faulty Replace sensor

Display drift Sensor faulty Replace sensor

Calibration not possible Calibration is blocked Set calibration switch to "on"

Wrong test weight
Sensor faulty Replace sensor

Cornerload outside tolerance Sensor faulty Replace sensor

Linearity outside tolerance Balance not linearized Relinearize balance

Sensor faulty Replace sensor

-8- Service manual ME-709116 06/92

BD balances Repairs

6. Repairs

The repairs described here comprise replacement work. Repairs of assemblies are not planned.

6.1 Opening and closing the balance

• Disconnect balance from power supply.

• Take off round weighing pan.
• Turn balance upside down.
• In the BD6000 case unscrew the middle screw.
• Unscrew 4 screws in housing base and take off base.
• Close balance in reverse order.

6.2 Changing the housing

• Open balance.
• Dismantle sensor from old housing and install in new housing.
• Dismantle board and, if fitted, interface from old housing and install in new housing.
• Dismantle battery holder from old housing and install in new housing.
• Close balance.
• Perform settings and adjustment, see section 7.

6.3 Replacing the sensor

Note
Sensor replacement also entails replacement of the EEPROM.
• Open balance.
• Remove model plate.
• Disconnect ribbon cable from board.
• Remove 2 fastener screws and lift out faulty sensor.
• Install new sensor and screw on.

Caution
• When tightening the screws, ensure that the overload screw does not touch the housing.
• Do not touch the leads of the sensor!

Service manual ME-709116 11/92 -9-

Repairs BD balances

Replacing EEPROM (on replacing the sensor)

• Unscrew 2 screws of board, turn board over.
1
• Remove EEPROM with the data of the defective
sensor and insert new EEPROM.
• Install board.
• Reaffix model plate.
• Close balance.

6.4 Replacing the board

Defining the balance model on the exchange board

Before installation the new board unit must be defined
using the solder shorts E1 … E4.
• Solder the solder shorts as follows:
BD202 –
BD601 E1
BD1201 E1, E2
BD6000 E2, E3
BD601L E1, E4

Replacing the board

• Open balance.
• Disconnect cables of battery holder.
• Disconnect ribbon cable from sensor at the board.
• If fitted, remove interface and disconnect cable at the board.
• Remove 3 screws on the board.
• Remove board with power cable.
• Remove EEPROM from the defective board and install on new board.
• Installation in reverse order, for the adjustment first install the service interface.

- 10 - Service manual ME-709116 11/92

BD balances Settings and adjustment

7. Settings and adjustment

The following settings and adjustments must be performed after repair work:
• Check overload protection and, if fitted, adjust it
• Drift compensation
• Linearity adjustment
The service interface has to be installed for this work.

7.1 Adjusting the overload protection

After replacement of the sensor, the overload protection must be adjusted.

• With the weighing pan removed, turn the overload screw until it just touches the housing: for this, use the
enclosed allen key 3/32".
• Unscrew overload screw by 4 turns.
• Mount weighing pan, in the BD6000 case with the screw.
• Select "SE.0" in the menu, the linearization procedure starts, see section 7.3.
Caution
The overload protection is not yet active! Hence place the requested weight carefully on the weighing pan.
• When "C donE" and "0.00 g" are displayed, load 150 % maximum load (for example 300 g with BD202).
The overload protection is correctly set when 130 % to 145 % of the maximum load is now displayed.
If more than 145 % is displayed, take off weighing pan and turn overload screw 1/8 turn clockwise.
If less than 130 % is displayed, remove weighing pan and turn overload screw 1/8 turn counterclockwise.
• Retest overload protection with 150 % maximum load.

7.2 Drift compensation

• Select "SE.1" in the menu.

Display Action

se. 1 Press and hold menu key until "Stored" appears.

- - - -

load Load full load.

650 ... 0 Balance counts down from 650.

0.00 9
Full load is tared, remove full load.

The drift is now compensated.

The balance must absolutely now be linearized, see section 7.3.

Service manual ME-709116 06/92 - 11 -

Settings and adjustment BD balances

7.3 Linearity adjustment

• Select "SE.0" in the menu.

Example: BD202

Display Action

se. 0 Press and hold menu key until - - - - appears.

100 9
flashes Load requested calibration weight (half load).

- - - -

200 9
flashes Load requested calibration weight (full load).

- - - -

0 9
flashes Remove weight.

- - - -

0.00 9
The balance is linearized and is again in the weighing mode.

- 12 - Service manual ME-709116 06/92

BD balances Technical data and adjustment tolerances

8. Technical data and adjustment tolerances

Note
All tolerances are listed in the greater readability of the service mode.
If a service interface is built in the switch key allows changing between normal and service mode display.

8.1 Weighing range, readability, cornerload and overload

Range Readability Cornerload Overload

Normal Normal Service mode Test factor 1) Test weight Tolerance Test weight Display

BD202 200 g 0.01 g 0.002 g 5 100 g ± 0.016 g 300 g 260 - 290 g

BD601 600 g 0.1 g 0.02 g 5 300 g ± 0.16 g 900 g 780 - 870 g

BD1201 1200 g 0.1 g 0.02 g 5 600 g ± 0.16 g 1800 g 1560 - 1740 g

BD6000 6000 g 1g 0.2 g 5 3000 g ± 1.6 g 9000 g 7800 - 8700 g

BD601L 600 g 0.1 g 0.02 g 5 300 g ± 0.16 g 900 g 780 - 870 g

1)
The readability in the service mode is greater than in weighing operation by the test factor.

8.2 Linearity, calibration weight and temperature compensation

Linearity Calibration weight Temperature compensation Hysteresis

Tolerance (up) 1) Tol. zero °C Tol. sens. °C Tolerance

BD202 ± 0.006 g 200 g ± 0.02 g ± 0.006 g ± 0.012 g

BD601 ± 0.06 g 500 g ± 0.1 g ± 0.018 g ± 0.12 g

BD1201 ± 0.06 g 1000 g ± 0.2 g ± 0.036 g ± 0.12 g

BD6000 ± 0.6 g 2 x 2000 g ±1g ± 0.18 g ± 1.2 g

BD601L ± 0.06 g 500 g ± 0.02 g ± 0.012 g ± 0.12 g

1)
Admissible display error at 1/4, 1/2 and 3/4 full load when there is no error in the zero point and the full load
display.

Service manual ME-709116 11/92 - 13 -

Service bulletins BD balances

9. Service bulletins

Is my service manual really up to date?

At the bottom right of the title page you will find the date of issue. If you know the date of the latest edition,
you can thus see whether your service manual is up to date.
If this is not the case, the latest service bulletin has not been filed. (The service bulletins represent a
continuous supplement to the service manual and keep it up to date.)
The service bulletin always includes a new title page for the service manual, new pages and pages to be
exchanged, as well as a new contents page for the section "Service bulletins". All these documents have the
same, latest date of issue at the bottom of the page.
First edition of the "METTLER BD balances" service manual: June 1992 (06/92)

Contents section 9 Date of issue

1. Service bulletin ME-705130 11/92

BD balances

- 14 - Service manual ME-709116 11/92

 TECHNICAL DOCUMENTATION

Address Mettler-Toledo AG, CH-8606 Greifensee

Telephon 01-944 22 11
Telefax 01-944 30 80
Telex 826150 mig ch

Service Bulletin

METTLER
BD balances

Supplement to service manual

BD balances ME-709116

The board replacement was not completely described in the first edition of the service manual.
This service bulletin provides the necessary supplement.
Please file the pages of the service bulletin as follows:
• Replace title page of the service manual
• Replace pages 9/10
• Replace pages 13/14

P705130

© Mettler-Toledo AG 1992 ME-705130 Printed in Germany 9211/38.12

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