Adam Equipment WBZ Series User manual

© Adam Equipment Company 2008
Adam Equipment
WBZ SERIES
Service Manual
rev E, Software rev.: 2.22 & above
ADAM EQUIPMENT CO. LTD.
P.N. 9046, Rev. E November 2009

© Adam Equipment Company 2008 1
CONTENTS
1.0 INTRODUCTION ...................................................................................................... 3
2.0 SPECIFICATIONS.................................................................................................... 3
3.0 TROUBLESHOOTING ............................................................................................. 4
4.0 ERROR CODES....................................................................................................... 5
5.0 WBZ DESCRIPTION ................................................................................................ 5
6.0 LOAD CELL DAMAGE ............................................................................................. 6
7.0 CALIBRATION.......................................................................................................... 9
7.1 CALIBRATION PROCEDURE .............................................................................. 9
7.2 SECURITY SEALS ............................................................................................... 9
7.3 CALIBRATION / PARAMETER COUNTER......................................................... 10
8.0 SERVICE PARAMETERS ...................................................................................... 12
8.1 USING “0000” TO ENTER THE CALIBRATION PARAMETER ........................... 12
8.2 USING “2006” TO ENTER THE SERVICE PARAMETERS ................................. 13
8.2.1 F1 -CAL............................................................................................................. 14
8.2.2 F2 –100G.......................................................................................................... 14
8.2.3 F3 –UNIT .......................................................................................................... 15
8.2.4 F4 -CAPACITY ................................................................................................. 15
8.2.5 F5 -UNIT PRICE/TOTAL PRICE DECIMAL POINT LOCATION ...................... 16
8.2.6 F6 -INITIAL ZERO RANGE .............................................................................. 16
8.2.7 F7 -RE-ZERO RANGE...................................................................................... 17
8.2.8 F8 -SUCCESSIVE TARE.................................................................................. 17
8.2.9 F9 -A/D COUNT ............................................................................................... 18
8.2.10 F10 –ROUNDING OFF THE TOTAL PRICE ................................................. 18
8.2.11 F11 –ZERO .................................................................................................... 19
8.2.12 F12 –LOW VOLTAGE DETECTION.............................................................. 19
8.2.14 F14 –AUTO CLEAR....................................................................................... 20
8.2.15 F15 – CALIBRATION and PARAMETER COUNTING ENABLED ................ 20
8.3 SETTING THE SCALE TO USE DEFAULT PARAMETERS................................ 22
8.4 TESTING WITH X10 FUNCTION ........................................................................ 22
9.0 WIRING DIAGRAM ................................................................................................ 23
10.0 MECHANICAL ASSEMBLY.................................................................................... 24

© Adam Equipment Company 2008 2

© Adam Equipment Company 2008 3
1.0 INTRODUCTION
The WBZ series of digital price-computing scales are EC Type approved. These scales
provide an accurate, fast and versatile method of computing price by weight.
•Stainless steel weighing platform on an ABS plastic base assembly which is
sealed to IP 65, making it water-proof
•Level indicator with adjustable levelling feet
•Colour coded, sealed keypad
•Large backlit liquid crystal displays (LCD) on both front and back panels
•Displays for Weight, Unit Price and Total Price (or Price to Pay)
•Price per 100g and per kilogram (Not applicable for South Africa and Far
East)
•Price displayed in multiple currency
•Auto-sleep function
•Battery operated for portability
•50+ hours battery life when fully charged
2.0 SPECIFICATIONS
WBZ 3 WBZ 6 WBZ 15
Capacity, Max.= 3 kg 6 kg 15 kg
Resolution, d=e= 0.001 kg 0.002 kg 0.005 kg
Tare, T= -3 kg -6 kg -9.995 kg
Operating Temperature -10ºC to 40ºC
Platform 210 x 173 mm
Overall
231 x 265 x 153 mm
Battery Life 50+ hours typical*
Power 12 VDC, 800 mA Power Supply Module-
supplied as standard
Net Weight 3.3 kg / 7.26 lb
*Battery Life is less when the backlight is used.

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3.0 TROUBLESHOOTING
PROBLEM POSSIBLE CAUSE
Display is blank Power Switch faulty or not connected
No turn on test Battery not charged or faulty
Power supply faulty or incorrect type
“- - - - - -“appears on display Maximum capacity exceeded
Load Cell damaged
Electronics is faulty
Display is unstable Drafts or air currents
Obstruction under pan
Sample is moving (animal weighing)
Vibrations through table
Temperature changed dramatically
Electronics faulty or Battery low
Weight value incorrect Calibration error, Recalibrate
Unit calibrated with inaccurate weight
Balance not level
Obstruction between sample pan
Wrong unit of weight displayed
Cannot use Full Capacity Over-load Stops hitting pan support or hitting
bottom of load cell
Electronics faulty
Parameters set incorrectly
Load Cell Damaged
Not Linear Overload stops hitting too soon
Faulty factory calibration
Off Centre Loading error Overload Stops not correct
Obstruction under pan
Battery will not charge Charging circuit failure
Battery Failure
Incorrect adapter (below 800 mA)
Processor failure

© Adam Equipment Company 2008 5
4.0 ERROR CODES
During the initial power-on testing or during operation, the scale may show an error
message. If an error message is shown, repeat the step that caused the message. If the
error is still shown contact your supplier for support.
ERROR DESCRIPTION POSSIBLE CAUSES
Err 4
Initial Zero is greater than
allowed (typically 4% of the
maximum capacity) when
power is turned on or when
[Tare] is pressed,
Weight is on the pan when
turning the scale on.
Excessive weight on the pan
when zeroing scale.
Improper calibration of the scale.
Damaged load cell.
Damaged Electronics.
Err 6
A/D count is not correct when
turning the scale on.
Platform is not installed.
Load cell is damaged.
Electronics is damaged.
5.0 WBZ DESCRIPTION
The WBZ scales have an enclosure with all components mounted within it. To gain access
to the components remove the 5 screws securing the cover to the base.
The basic unit consists of:
Base
Load Cell frame
Main PCB assembly
Battery
Display PCB assembly
Keypad
All models of WBZ scales are similar except the selection of load cells and the program.
Normally if a problem is found with a circuit board the most cost effective method of
solving the problem is to replace the circuit board.

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The main PCB assembly includes:
A/D converter (AU1),
Microprocessor (DU1) and
Power supply/battery charger circuits (DU5, T2).
6.0 LOAD CELL DAMAGE
The most common reason why a scale fails is that the load cell has been damaged. The
damage can be from 2 primary causes. The first is physical damage due to an overload or
an impact from the side and the second is damage due to the environment, such as
moisture, extreme heat or a cut cable if the cables are exposed.
PRINCIPLE OF OPERATION
The stain gauge load cell is a method of measuring the amount of stress put onto a metal
structure due to a weight being supported by the structure. The stress is measured using
4 strain gauge sensors mounted in a particular way on the metal structure.
These 4 strain gauges are connected in such a way that they form a Wheatstone Bridge.
See figure below. In the simplest load cells there are only the 4 resistances of the strain
gauges to consider. Normally without a load on the load cell all the resistances are the
same. However when the load cell has a weight on it 2 of the strain gages will be in
compression (A and D) and the resistance will decrease and 2 will be in tension (B and C)
and their resistance will increase.
350 ohm
350 ohm
350ohm
350ohm
AB
CD
+E
-S
-E
+S
BALANCED BRIDGE
10 VOLT POWER
SUPPLY
Vout = O VOLTS,
BETWEEN +S AND -s
351ohm
349ohm
351ohm
349ohm
AB
CD
+E
-S
-E
+S
UNBALANCED BRIDGE
FULL CAPACITY LOAD
ON THE LOAD CELL
10 VOLT POWER
SUPPLY
Vout = 0.028 VOLTS (28mv),
BETWEEN +S AND -s
This will cause the bridge to become unbalanced. When the bridge has a voltage across it
from +E to -E then the signal output at +S and -S will show a voltage of zero volts with no
load and a small voltage proportional to the load as the load is increased. Typical load
cells show 20-30mv of signal if the excitation voltage is 10volts and the load cell is fully
loaded.
Most load cells used in scales are not as simple as this example. They have additional
resistance elements added to compensate for temperature variations and to set the
outputs to correct voltages. The circuit of a typical load cell is shown below-

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A method to check the basic function and integrity of a load cell can be done using a
ohmmeter and voltmeter with up to a 10volt power supply.
Before the load cell is connected to the power supply use the ohmmeter to measure the
resistance between the wires. Typical resistance values are:
+E to -E 410 ohms ±30 ohms
+S to -S 350 ohms ± 2 ohms
+E to +S or any other combination similar approximately 270 ohms.
If the load cell has Sense connections in addition they are connected to the excitation
internal to the load cell.
Connect the load cell +E and -E to a power supply, typically 10 volts. Never use more
than 12 volts as it may damage the load cell.
Measure the voltage between +S and -S.
With no load the voltage should be approximate 0mv ±3mv.
With a mass on the load cell the output voltage should increase. The amount by which it
increases will be dependent upon the sensitivity of the load cell, capacity of the load cell,
the excitation voltage and the amount of mass placed on the load cell. Most load cells
have a sensitivity of either 2mv/V or 3mv/V.
The expected change to the output is:
Vout = (2mv/V) * Vext * Mass
capacity of load cell
For example a 2mv/V load cell of 30Kg capacity with 20Kg placed on it. Vext is 5 volts
would give a output of approximately:

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Vout = (2mv/V) * Vext * Mass = 2mv/V * 5V * 20Kg = 6.7mv
capacity of load cell 30kg
If the load cell has been damaged the no load voltage will likely be greater than 3mv or the
loaded voltage will be grossly different from the expected value. Remember the loaded
voltage will be offset by the amount of zero load voltage measured.
The load cell can be tested while it is connected to the A/D, using the scale power supply
for excitation voltage.

© Adam Equipment Company 2008 9
7.0 CALIBRATION
7.1 CALIBRATION PROCEDURE
The scales have methods to either prevent or control unauthorised calibration. If the
Calibration Counters are enabled the scales can be calibrated without breaking the seals,
however the counters will be incremented to identify a calibration or change in parameters.
If the scales do not have the counters enabled then access is controlled by breaking the
seals on the scale to gain access to the circuit boards inside. See the figures on the
security seal as given below.
WARNING: BREAKING OF THE SEALS MAY MAKE IT ILLEGAL TO USE THE SCALES
FOR SALES OF GOODS. CONTACT YOUR TRADING STANDARDS OFFICE FOR
FURTHER ASSISTANCE.
7.2 SECURITY SEALS
Method of sealing
Alternative method
The scale has got metallic loops on the base
and the cover, located at the right rear corner
as shown here. A metal pin or wire can be
passed through the loops and sealed using a
lead-wire seal. Ensure the seal is secured
enough to prevent removing the cover
without breaking the seal or damaging the
enclosure.
An alternative method would be to use
tamper-evident labels over the screw on the
bottom cover and over the joint between the
top and the bottom cover as shown in the
adjacent figure.
Metrology labels and additional security
measures may be added to the scale as
required by the national legislation.
NOTE: IF THIS SEAL IS BROKEN THE SCALE MUST BE RE-SEALED BY
THE RELEVANT AUTHORITIES USING EITHER THE LEAD WIRE SEAL
OR AN ACCEPTABLE SEAL BETWEEN THE COVER AND THE BASE.

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7.3 CALIBRATION / PARAMETER COUNTER
With approved scales we have the ability to control access to the calibration
or metrology parameters using a passcode to limit access. The
requirements for doing this stipulate the code should be apparent and
recorded in a suitable location on the scale.
In this way if the record of the Calibration or Parameter counters do not agree
with recoded settings the responsible person inspecting the scale can take
appropriate action.
The Counters are incremented any time the calibration section or the Factory
parameters section have been entered and changes made.
At power on, the display will show the current software revision number
followed by the message of the Calibration Count “[AL[nt” then “123”. The
number from the counter memory. Then the Parameter Counter message of
“PAr[nt” and “234”. The counters cannot be reset to 0, they will increment
until the display can no longer hold the values. (1 to 999999). It is expected
we will never have more than 1 million calibrations in the life of the machine.
Each display is held for 1-2 seconds.
The scale will then continue to do the display test and go to normal weighing.
If during the time the counting displays are shown, the user presses the
[Tare] key, the user will be given a message to enter the passcode
necessary, “P - - - - “ Enter the code “P0000” to Enter calibration or
“P1000” to enter the parameters. The Calibration access will allow user
calibration (See section 8.1) and the parameter code will allow access to the
following parameters. (see section 8.2).

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F2 100g Enable price per 100g or per kg option
F5 Point Unit Price/Price decimal point
F6 init ZEro Initial Zero Range
F7 rE ZEro Re-Zero range
F8 SCSivE tArE Successive Tare Enable
F9 Ad Count Display the A/D counts
F10 round Rounding off the Total Price
F11 ZEro Select the zero mode
F12 Lvd mod Low voltage detection
F13 CAL b tt Set calibration of battery voltage measurements
F14 ACLr Not used, Auto Clear is always enabled
F15 CAL Cnt Enable or disable the calibration counters
Other parameters must be changed using the service parameters as
described in section 8.2
After calibration or changing of any parameters the value of the counters is
required to be visible on the scale marked in a permanent manner. Adam
Equipment supplies a label for this purpose, to be placed near the verification
marks on the side of the scale.
Any time these values change the scale is required to be retested by the
appropriate authorities in the users location.

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8.0 SERVICE PARAMETERS
After the jumper has been placed at J1 on pins 1 &2, apply power to the scale or use the
Calibration Count method as described in section 7.3 to access the passcode display if the
Counting method has been enabled.
The display will ask for a code number, “P - - - - “.
Enter the number 1000 or 2006. To enter the digits, using the number keys. Press the
[Tare] key to accept the value
The display will show the first parameter allowed depending upon the passcode entered,
code 1000 only allows access to a limited number of parameters, see section 7.3. If code
2006 was entered the first parameter is: “F1 CAL”. To scroll through other parameters
press the [0] key.
The display will show the parameter number then the word describing the function.
Press the [Tare] key to enter a parameter.
Press the [Zero] key to exit a parameter. Pressing [Zero] again will display “ JP on” if a
jumper was used to gain access. Remove the jumper. The scale will return to normal
weighing.
8.1 USING “0000” TO ENTER THE CALIBRATION PARAMETER
After the jumper has been placed at J1 on pins 1 &2, apply power to the scale or use the
Calibration Count method as described in section 7.3 to access the passcode display if the
Counting method has been enabled.
“P n ” When “P n ” is displayed, enter “ 0 0 0 0 ” and
press [Tare].
“ U n LoA d ”
Empty the pan by removing the load, if there
is any and press [Tare].
“ LoA d” “ 6 ” “ K i LoS ”
Load the requested calibration weight and
when stable press [Tare].
“ SPA n” “ PASS ”
If Calibration is complete, “SPA n PASS” will
be displayed. Remove the calibration
weight.

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Or, “ SPA n” “ FA i L ”
This means calibration has failed. Remove
the calibration weight and repeat the
process.
“ JP On ”
This is shown only if a jumper was used to
gain access. Switch off the scale. Remove
the jumper. Switch on the scale for normal
weighing.
8.2 USING “2006” TO ENTER THE SERVICE PARAMETERS
After the jumper has been placed at J1 on pins 1 &2, apply power to the scale or use the
Calibration Count method as described in section 7.3 to access the passcode display if the
Counting method has been enabled.
Display will ask for a code number, “ Pn “ on the Unit Price window.
Enter the number 2006 when “ Pn “ is displayed and then press [Tare].
The displays will show the first parameters, called “ F1 ” “ CAL ”. To select another parameter
press the [0] key to advance through the parameters.
Press the [Tare] key to enter a parameter.
To exit a parameter, press the [

Z

]key.
The Weight Display window will show the parameter number and the Unit Price window
will show the word describing the function.
When a parameter is entered by pressing the [Tare] key, the displays will guide you
through the parameter selected and the options available.
The parameters available are:
F1 CAL To enter the Calibration
F2 100g Enable price per 100g or per kg option
F3 Unit Select kilograms or pounds
F4 CAPA Select capacity
F5 Point Unit Price/Price decimal point

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F6 init ZEro Initial Zero Range
F7 rE ZEro Re-Zero range
F8 SCSivE tArE Successive Tare Enable
F9 Ad Count Display the A/D counts
F10 round Rounding off the Total Price
F11 ZEro Select the zero mode
F12 Lvd mod Low voltage detection
F13 CAL b tt Set calibration of battery voltage measurements
F14 ACLr Not active,
F15 C l Cnt Enable or disable the Calibration Counting function
8.2.1 F1 -CAL
To advance to the next parameter, press the [0] key or to enter the calibration parameter
press the [Tare] key when “ F1 CAL ” is displayed.
The display will instruct you to remove any weight from the scale, “ UnLoAd ”. Press [Tare].
The display will tell you to add weight to the scale: “ LoAd ” “ 6 ” “ kiloS ”
Add the weight shown, wait for stability then press the [Tare] key.
The display will show “ SPAn ” “ PASS ” if the calibration is OK. Or it will show “ SPAn ” “ FAIL ” if
calibration could not be completed correctly.
The display will then show “ JP on ” indicating the jumper is still in place if it was used to
gain access. Remove the weight. Switch off the scale and switch it on to continue with
the other Service parameters.
8.2.2 F2 –100G
To enter this parameter, press the [Tare] key when “ F2 100G ” is shown.
The display will show “ PriCE “ “ on ” or “ PriCE “ “ oFF ” .

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“ PriCE “ “ on ” User will not be allowed to change the price per 100g to kg (or 0.1 lb
to pounds if pound is selected in F3).
“ PriCE “ “ oFF ” . User will be allowed to change the price per 100g to kg (or 0.1 lb to
pounds if pound is selected in F3).
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter. Press the [0] key
to advance to the next parameter.
8.2.3 F3 –UNIT
Select either kilograms or pounds weighing units.
To enter this parameter, press the [Tare] key when “ F3 ” is shown.
The display will show the current unit, either kilograms or pounds.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
8.2.4 F4 -CAPACITY
To enter this parameter, press the [Tare] key when “ F4 ” is shown.
The display will show the current capacity: 3, 6 or 15 kilograms.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value.

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NOTE: The scale must be originally built for the capacity selected. The 3kg unit uses the
5kg load cells, 6 kg unit uses 10kg load cells, the 15 kg unit uses 20 kg load cells.
8.2.5 F5 -UNIT PRICE/TOTAL PRICE DECIMAL POINT LOCATION
To enter this parameter, press the [Zero/Tare] key when “ F5 ” is shown.
The display will show the current decimal point location in the Unit Price and the Total
Price windows.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
NOTE: The units must match the currency used in the country. Normally 0.00 is shown.
8.2.6 F6 -INITIAL ZERO RANGE
To enter this parameter, press the [Tare] key when “ F6 ” is shown.
The display will show the current initial zero range.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
NOTE: Only 10% is allowed for the WBZ scales.

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8.2.7 F7 -RE-ZERO RANGE
To enter this parameter, press the [Tare] key when “ F7 ” is shown.
The display will show the current re-zero range.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
NOTE: Only 2% is allowed for the WBZ scales.
8.2.8 F8 -SUCCESSIVE TARE
To enter this parameter, press the [Tare] key when “ F8 ” is shown.
The display will show if the successive tare is on or off.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
NOTE: Either option is allowed for the WBZ scales, use On for default.

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8.2.9 F9 -A/D COUNT
To enter this parameter, press the [Tare] key when “ F9 ” is shown.
This parameter allows you to view the A/D counts from the internal A/D converter. This can
be an aid to service.
Press the [0] key to advance to the next parameter.
8.2.10 F10 –ROUNDING OFF THE TOTAL PRICE
This parameter allows you to set the value to 1 or 5 for rounding off the least significant
digit of the Total Price. For example, if the value is set to 1, the Total Price will remain as
12.47 for the original value of 12.47 and if it is set to 5, the Total Price will be rounded off
to 12.45 instead of 12.47.
To enter this parameter, press the [Tare] key when “ F10 ” is shown.
The display will show the current settings.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.

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8.2.11 F11 –ZERO
This parameter allows the normal method of setting zero or a slightly different method
required for Sri Lanka to be used.
To enter this parameter, press the [Tare] key when “ F11 ” is shown.
The display will show the current settings, “ modE 1 ” or “ modE 2 ”.
“ modE 1 ” is to be selected at all times unless the scale is intended for Sri Lanka.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
8.2.12 F12 –LOW VOLTAGE DETECTION
This parameter allows detection of low voltage when the battery wears down.
To enter this parameter, press the [Tare] key when “ F12 ” is shown.
The display will show if the LVD Mode is set to on or off.
Press the [0] key to change the value.
Press [Tare] to accept the displayed value and return to the parameter.
Press the [0] key to advance to the next parameter.
NOTE: Only the “on” option is allowed for the WBZ scales. Set to off only for testing or to
allow operation before the battery voltage calibration is completed.