Adam Equipment WBW Series User manual

© Adam Equipment Company 2008
.
Adam Equipment
WBW SERIES
Service Manual
Software rev.: 2.xx and above
ADAM EQUIPMENT CO. LTD.
P.N. 9035, Rev. D, May 2009

© Adam Equipment Company 2008

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CONTENTS
1.0 INTRODUCTION ...................................................................................................... 3
2.0 SPECIFICATIONS.................................................................................................... 5
3.0 TROUBLESHOOTING ............................................................................................. 7
4.0 ERROR CODES....................................................................................................... 8
5.0 WBW DESCRIPTION............................................................................................... 9
6.0 LOAD CELL DAMAGE ............................................................................................. 9
7.0 FACTORY PARAMETERS..................................................................................... 12
7.1 F1 -CALIBRATION ............................................................................................... 13
7.2 F2 – CAPACITY ................................................................................................... 14
7.3 F3 -INITIAL ZERO RANGE .................................................................................. 14
7.4 F4 -RE-ZERO RANGE ......................................................................................... 15
7.5 F5 -SUCCESSIVE TARE ..................................................................................... 15
7.6 F6 -A/D COUNT ................................................................................................... 15
7.7 F7 –LOW VOLTAGE DETECT ............................................................................. 15
7.8 F8 –WEIGHING UNITS ALLOWED...................................................................... 16
8.0 WIRING DIAGRAM ................................................................................................ 17
9.0 MECHANICAL ASSEMBLY.................................................................................... 18
*****

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1.0 INTRODUCTION
•The WBW range provides accurate, fast and versatile general purpose
weighing scales with check-weighing functions.
•There are two series within the range. The WBWa series of scales are
similar to the WBW series of scales except the default units are pounds,
whereas in the WBW series the imperial units are disabled which can be
enabled by the user.
•There are 4 models in each series with capacities up to 16 kg / 35 lb.
•All have stainless steel weighing platforms on an ABS plastic base assembly
which is sealed to IP 65.
•All scales have sealed keypads with colour coded membrane switches and
the displays are large easy to read liquid crystal type displays (LCD). The
LCD’s are supplied with a backlight.
•The scales include automatic zero tracking, audible alarm for pre-set weights
and semi-automatic tare.

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2.0 SPECIFICATIONS
WBWa Series (USA models)
WBW 2
WBW 5a
WBW 4
WBW 9a
WBW 8
WBW 18a
WBW 16
WBW 35a
Pounds
Maximum Capacity 5 lb 9 lb 18 lb 35 lb
Tare Range -5 lb -9 lb -18 lb -35 lb
Readability 0.0005 lb 0.001 lb 0.002 lb 0.005 lb
Repeatability (S.D.) 0.0005 lb 0.001 lb 0.002 lb 0.005 lb
Linearity (±) 0.001 lb 0.002 lb 0.004 lb 0.01 lb
Ounces
Maximum Capacity 80 oz 144 oz 288 oz 560 oz
Readability 0.01 oz 0.02 oz 0.05 oz 0.1 oz
Repeatability (S.D.) 0.01 oz 0.02 oz 0.05 oz 0.1 oz
Linearity (±) 0.02 oz 0.04 oz 0.1 oz 0.2 oz
Pounds:Ounces
Maximum Capacity 5 lb: 0.00 oz 9 lb:0.00 oz 18 lb:0.0 oz 35 lb: 0.0 oz
Readability 0.01 oz 0.02 oz 0.1 oz 0.1 oz
Repeatability (S.D.) 0.01 oz 0.02 oz 0.1 oz 0.1 oz
Linearity (±) 0.02 oz 0.04 oz 0.2 oz 0.2 oz
Kilograms
Maximum Capacity 2.000 kg 4.000 kg 8.000 kg 16.000 kg
Readability 0.0002 kg 0.0005 kg 0.001 kg 0.002 kg
Repeatability (S.D.) 0.0002 kg 0.0005 kg 0.001 kg 0.002 kg
Linearity (±) 0.0004 kg 0.001 kg 0.002 kg 0.004 kg
Grams
Maximum Capacity 2000 g 4000 g 8000 g 16000 g
Readability 0.2 g 0.5 g 1 g 2 g
Repeatability (S.D.) 0.2 g 0.5 g 1 g 2 g
Linearity (±) 0.4 g 1 g 2 g 4 g

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OTHER SPECIFICATIONS
Units of measure kg, g, lb, oz, lb:oz
Tare Full range
Stabilisation Time 2 seconds typical
Operating
Temperature
-10°C - 40°C
Power supply 9 -12VDC, 800 mA
Through an external Power Supply Module
Battery Internal rechargeable battery (~50 hours operation)
Calibration Automatic External
Display 6 digits LCD digital display
with capacity tracker and symbols for units
Scale Housing IP 65 Sealed ABS Plastic housing with
Stainless Steel pan
Pan Size 210 x 173 mm
Overall Dimensions
(wxdxh)
231 x 265 x 153 mm
Net Weight 2 kg
Applications Weighing Scales
Functions Weighing, Check weighing

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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
E6 is displayed Pan not installed
Poor connection
Load cell damaged
Electronics faulty
“- - OL - -“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

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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
4.0 ERROR CODES
ERROR
CODE
DESCRIPTION POSSIBLE CAUSES
Err 4
Initial Zero is greater than
allowed (4% of maximum
capacity) when power is turned
on or when the [Zero/Enter]
key is pressed.
Weight on the pan when turning the
scale on.
Excessive weight on the pan when
zeroing the scale.
Platform is not installed.
Improper calibration of the scale.
Damaged load cell.
Damaged Electronics.
Err 6
A/D count is not correct when
turning the scale on.
Load cell is damaged.
Electronics is damaged.
Err 8
High limit input error Low limit is set first, then the high limit is
set lower than the low limit and high
limit not equal to zero.
Err 9
Low limit input error High limit is set first, then the low limit is
set higher than the high limit and low
limit not equal to zero.
FAIL H or
FAIL L
Calibration error Improper calibration (should be within
+10% of the factory calibration). The old
calibration data will be retained until the
calibration process is complete.

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5.0 WBW DESCRIPTION
The WBW scales have an enclosure with all components mounted within it. To gain
access to the components remove all the screws securing the cover to the base, the pan
support to the frame and the rubber gasket between the cover and the frame.
The basic unit consists of:
Base
Load Cell frame
Main PCB assembly
Battery
Keypad
All models of WBW 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.
The main PCB assembly includes:
A/D converter,
Microprocessor and
Power supply/battery charger circuits
LCD display with backlight
6.0 LOAD CELL DAMAGE
The most common reason 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 gage 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

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gages 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:
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

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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 converter circuit board, using
the scale power supply for excitation voltage.
7.0 FACTORY PARAMETERS
The factory parameters are used for setting the capacity and basic settings.
Switch off the scale and then switch on again. Press [Tare] during the initial self-test.
The display will ask for a code number, “P _ _ _ _ “.
Enter the number 1000 and press [Tare].
The display will show the first parameter “F1 CAL”. To scroll through other parameters
press the [Limit] 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 return the scale to
weighing.
When a parameter is entered by pressing the [Tare] key, the display will guide you
through the parameter selected and the options available.
The parameters available are:
F1 CAL To enter the Calibration
F2 CAP Select Capacity
F3 int Initial Zero Range
F4 rE Z Re-Zero Range
F5 SCS Successive Tare Enable
F6 Cnt Display the A/D counts
F7 Ldv Set low voltage detect mode
F8 Uin Calibration/parameter counter enabled

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7.1 F1 -CALIBRATION
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 the first weight to the scale: “ Ld 1 OO kg”
Place the first calibration weight as suggested in the Table below. Wait for stability then
press the [Tare] key.
The display will tell you to add the second weight to the scale: “ Ld 2 kg”
Place the second calibration weight as suggested in the Table below. Wait for stability then
press the [Tare] key.
The display will show “ PASS ” if the calibration is OK. Or it will show “ FAIL L ” if calibration
could not be completed correctly.
The scale will return to weighing. Remove the calibration weight.
Suggested Calibration Weights:
Calibration weight 1 Calibration Weight 2
WBW 2/5a 1 kg 2 kg
WBW 4/9a 2 kg 4 kg
WBW 8/18a 5 kg 8 kg
WBW 16/35a 5 kg 15 kg
if the scales are weighing in an imperial unit the calibration can be done with pounds
weights. It is suggested weights of approximately ⅓to 2/3 maximum and near maximum
be used. For example
Calibration weight 1 Calibration Weight 2
WBW 2/5a 2 lb 5 lb

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WBW 4/9a 4 lb 9 lb
WBW 8/18a 10 lb 15 lb
WBW 16/35a 20 lb 30 lb
Other weights can be used as long as the value entered matches the weights used.
7.2 F2 – CAPACITY
To enter this parameter, press the [Tare] key when “ F2 CAP ” is shown.
The display will show the current capacity.
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.
NOTE: The scale must be originally built for the capacity selected. The 2 kg unit uses the
3 kg load cells, 4 kg unit uses 5 kg load cells, the 8 kg unit uses 10 kg load cells and the
16 kg unit uses 20 kg load cells.
7.3 F3 -INITIAL ZERO RANGE
To enter this parameter, press the [Tare] key when “ F3 int ” is shown.
The display will show the current initial zero range.
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.

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7.4 F4 -RE-ZERO RANGE
To enter this parameter, press the [Tare] key when “ F4 reZ ” is shown.
The display will show the current re-zero range.
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.
7.5 F5 -SUCCESSIVE TARE
To enter this parameter, press the [Tare] key when “ F5 SCS ” is shown.
The display will show if the successive tare is “ tr on ” or “ tr oFF ” .
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.
7.6 F6 -A/D COUNT
To enter this parameter, press the [Tare] key when “ F6 Cnt ” 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 [Tare] key to return to the PARAMETER menu.
The actual values are not critical as long as the ADC appears to be running, the values are
stable (±5) and there are approximately 200,000 -300,000 counts span.
7.7 F7 –LOW VOLTAGE DETECT
This parameter allows detection of low voltage when the battery wears down.

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To enter this parameter, press the [Tare] key when “ F8 Lvd ” is shown.
The display will show if the LVD Mode is set to on or oFF .
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.
7.8 F8 –WEIGHING UNITS ALLOWED
This parameter enables the weighing units the user is allowed to select from when setting
his scale.
To enter this parameter, press the [Tare] key when “ F8 Uin ” is shown.
The display will show either Kg (kilograms) or Lb (Pounds). If the user selects kiograms,
only grams and kilograms will be available to him. If Pounds are selected, the user can
enable or disable kilograms, grams, pounds, ounces or pounds:ounces.
Press the [Limit] key to scroll through the options.
Press [Tare] to accept the displayed value and return to the parameter or press the [Zero]
key to return to the parameter without changing the value.
Then press [Limit] to advance to the next parameter.

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8.0 WIRING DIAGRAM

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9.0 MECHANICAL ASSEMBLY