Intelligent Weighing Technology QHD+3, QHD+6, QHD+15, QHD+30 Service Manual
QHD series
Counting Scale
SERVICE MANUAL
©Intelligent Weighing Technology, Inc. 2012. All rights reserved worldwide.
The information contained herein is the property of Intelligent Weighing Technology. and
is supplied without liability for errors or omissions. No part may be reproduced or used
except as authorized by contract or other written permission. The copyright and the
foregoing restriction on reproduction and use extend to all media in which the
information may be embodied.
CONTENTS
1. PRECAUTIONS……………………………………………………………………..4
2. INSTALLATION……...…………..…………………….…………………………..…5
3. NAME AND FUNCTIONS…………….…………………………………………7
Key board………………………………...................................................7
Display………………………………………………………………………8
4. OPERATION………………………………………………………….…………9
Power On/Off…………………….…………………………………………9
Switch to local / Remote Scale….…....………………………………….9
Zero……………………………….…………………………………………9
Tare………………………………………………………………………….9
Accumulation………………………………….………………………….10
Manual Accumulation……………………………………………………..10
Saved Data…………………………………………………………………10
Delete Data…………………………………………………………………10
Automatic Accumulation…………………………………………………..11
Parts Counting ………………………………………………………..…..11
Weighing a sample to determine the Unit Weight…………………….. 11
Enter a known Weight……………………………………………………..12
Automatic update of Unit Weight…………………………………………12
Check weighing of count pre-set…………………………………………12
Setting the checking limits………………………………………………..12
PLU (Product Look Up)………………………………………………….13
Storing PLU………………………………………………………………...13
Entering Description manually……………………………………………14
Recalling PLU……………………………………………………………...15
5. PARAMETERS…………………………………………………………………16
Keys into the parameter…………………………………………………..16
Parameter settings………………………………………………………...17
6. RS-232 OUT PUT………………………………………………………………18
7. CALIBRATION…………………………………………………………………21
8. TECHNICAL PAAMETER…………………………………………………….22
9. ERROR DISPLAY……………………………………………………………...24
10. TROUBLE SHOOTING…………………………………………………………25
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11. MAINTENANCE…………………………………………………………………27
Change Parts………………………………………………………………..27
Replace main board…………………………………………………………27
Replace display board……………………………………………………....28
Replace load cell…………………………………………………………….28
Replace battery………………………………………………………………28
Checking Components……………………………………………………29
Checking Load cell…………………………………………………………..29
Load cell connections……………………………………………………….29
Checking voltages…………………………………………………………30
12. CIRCUIT DIAGRAM……………………………………………………………..31
13. DRAWING………………………………………………………………………...33
Parts List……………………………………………………………………….34
14. SPECIFICATIONS………………………………………………………………..35
Specifications………………………………………………………………….35
Specification for Remote scale ……………………………………………..36
Specification for Local scale Load Cell……………………………………..36
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1. PRECAUTIONS
Read this manual before operating or servicing this
equipment.
Follow these instructions carefully.
Disconnect this equipment from the power source before
cleaning of performing maintenance.
Keep the manual for your future reference.
Avoid extremes of temperature. Do not place in direct
sunlight or near air conditioning vents.
Avoid unsuitable tables. The tables or floor must be rigid
and not vibrate. Do not place near vibrating machinery.
Avoid unstable power sources. Do not use near large
users of electricity such as welding equipment or large
motors.
Avoid high humidity that might cause condensation. Avoid
direct contact with water. Do not spray or immerse the
scales in water.
Avoid air movement such as from fans or opening doors.
Do not place near open windows.
Do not stack material on the scales when they are not in use.
Keep the scales clean.
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2. INSTALLATION
Unpacking
Carefully take the balance out of its package, make it sure its not damaged and all
accessories are included.
Accessories,
1. Balance
2. Adaptor
3. Stainless steel pan
4. Product manual
Keep the packaging material for your future use.
SETTINGS
Local Scale:
Place the scale on a table.
Place the platform in the locating holes on the top cover.
Do not press with excessive force as this could damage the load cell inside.
Check the water mark. If, bubble is not centre adjust the leveling feet until reach
centre. Check the level when you change the location.
Attach the power supply cable to the connector on the right side of the scale
base. Plug in the power supply module.
Turn on the Scale. The power switch is located at the right side of the scale base.
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The scale will be shown the model number in the “Weight” display and will be
start self test.
Remote Scale:
The QHD+ Series can be connected to any size of load cell type weighing base
through the Remote scale port on the left side of the scale case. Ensure you have
the correct base for the scale as each is matched for calibration.
Place the remote scale platform in the position where it is to be used. Level the
scale by adjusting the four feet. If fitted with a spirit level then it should be
adjusted such that the bubble is in the center.
Press key to change remote mode and check weighing performance.
Remote Scale Connection
The cable of the load cell goes to a 9 pin DB9 d-subminiature plug connecter with
following connections.
Pin Connection
1 and 2 Excitation+(5V)
4and 5 Excitation- (0v)
7 Signal8 Signal+
Note: The sense wires connections of a six wire load cell are not used but can be
connected to the respective Excitation pins.
Remote Scale Setup
The remote scale should set for a realistic resolution with respect to the input provided
by the load cell/s.
If a single 2mV/V load cell is fitted and more than 60% of the load cell is used for full
capacity then the high output of >6mV span makes it possible to set a high resolution.
If this criterion is met then the remote scale can be set to a high resolution with a
maximum of 1/30,000, for example: 300kg x 10g.
It will also be possible to sample on the remote scale with the same accuracy as the
Local.
Where more than one load cell is fitted or the total load cell capacity is not utilized then a
reduced resolution should be selected in the remote scale technical set up. For
example, if a system uses four 2mV/V 1000kg load cells for a scale of 1000kg capacity
then the span output at full scale will be only 2.5mV.
In this situation the resolution should be reduced to give a good number of ADC counts
per displayed division, for example, set to 1:5000 or 1000kg x 0.2kg.
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Setting a high resolution without providing a good input to the remote scale ADC will not
give better accuracy and may make the scale difficult to meet performance specification.
For best performance ensure a minimum of 0.1uV/d.
3. NAME AND FUNCTIONS
Key Board
Keys Press this key to
Numeric Keys. Enter to individual unit weights and the
to
present tare
Clear incorrect entries and error conditions
Decimal Point. Numeric input numbers select to the left.
Returns the display to zero.
Enter the clear tare weights, Storing the current weight as
tare value. Subtracting the tare value from the total weight
and displays the result as net weight.
Manually enter the weight of sample, also changes the unit
if they are enabled.
Enter the numbers of items, used for the unit weight.
Add the current count data aggregated. Also evokes the
memory if pressed to balance empty. Can add up to 99
values, or until it reaches the maximum displayable digits
Enter to store and recall the PLU
To set the upper limit of the number of items counted and
back light setting.
To select the local or remote scale.
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Display
The arrow “▼” above the symbols
Weight Display
Low Battery
Net Net Weight Display
Stable Stable Display
Zero Zeroing Display
Lb / kg Current Weighing Mode
Unit Weight Display
Smpl No of samples is very low
U.Wt Unit weight is below the minimum weight
M+ Data entered into the memory
Local / Remote Active Scale in use
Count Display
CkPcs Active in Counting Mode
Wt Active in Weighing Mode
High Check Result above the high limit
OK Check Result with in the limit
Low Check Result below the low limit
Charge Status of the battery charging
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4. OPERATION
Initial Start-up
Warm-up time of 15 minutes stabilizes the measured values after switching on.
1. Power ON/OFF
Power switch is located below the right side of the scale. Switch on the scale by
pressing on/off. The display is switched on and the self test is started.
If you want to switch off press backward the key.
2. Switch to Local / Remote Scale
By pressing the display changes from one to other scale.
In Local Scale
In Remote Scale
The basic weighing functions are same for both the scales- local and remote.
The number of weighing divisions may be less on the remote scale dependant
on the total capacity of the load cell/s used.
3. Zero
Environmental conditions can lead to the balance exactly zero in spite
of the pan not taking any strain. However, you can set the display of
your balance to zero any time by pressing key and therefore
ensure that the weighing starts at zero.
4. Tare
The weight of any container can be tared by pressing button so that with
subsequent weighing the net weight of the object being weighed is always
displayed.
Load weight on the pan.
Press key. Zero is displayed, and tare is subtracted.
Remove weight from the platform. Tared weight is displayed. It can
set only one tare value. It can display with a minus value.
Press key. Zero is displayed, tare weight is cleared.
Enter a tare value using by numeric keys.
This method allows you to enter a value for the tare weight from the
keypad. This is useful if all containers are the same or if the container is
already full but the net weight is required and the weight of the container is
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known.
Ensure display is in zero.
Enter the known tare weight by using numeric keys.
Press to enter, weight will be stored as tare weight and displayed with
minus sign and net indicator.
Place the container on the platform, net weight will be displayed.
The tare will be rounded up according to the readability of the
balance. For example, if a tare value of 103g is entered into the
60Kg scale with 5g readability, then the display will be shown -105g.
5. Accumulation
The balance can totalize weight values or count quantities.
Manual Accumulation
The values (weight and count) shown on display can be add to the memory
by pressing key. Set the parameter F1 off – print – au off
Place the goods to be weighed.
Wait few seconds for display stability then press .
The weight display will be show the total weight, the unit weight display will
be show the number of items and count display will be show the total
accumulated count. The values will be displayed 2 seconds.
The scale must return to come zero or negative number before adding
another samples.
More products can be added by pressing . It can add up to 99 entries
or until the capacity of the weight display is exceeded.
Display of Saved Data
To check the total value saved, press key when the display is in
zero. Total weight will be displayed two seconds.
Delete Saved Data
To clear the memory, press the display will be shown saved data.
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Press during the display, delete all saved accumulation data.
Automatic Accumulation
Weighing values automatically accumulate total, when the goods is
unloaded and with out key pressing.
Set the parameter F1 off – print – au on
Place the goods on the platform
Wait few seconds for display stability and a control beep.
Unload the goods from the platform, the weighing value is added into the
memory
The scale must return to come zero or negative number before adding
another samples.
It can add up to 99 entries or until the capacity of the weight display is
exceeded.
6. Parts Counting
In order to do parts counting, it is necessary to know the average weight of the items
to be counted. This can be done either by weighing a known number of the items
and letting the scale determine the average unit weight or by manually inputting a
known unit weight using the keypad.
To count a greater number of parts the average weight per part has to be determined
with a small quantity.
The average piece weight can be increased at any time during the counting process,
by entering the displayed number of items and confirming by pressing .
Weighing a sample to determine the Unit Weight
Reset the balance to zero or tare the empty container if necessary.
Place the known quantity of items on the scale, wait few seconds for display
stable.
Enter the number of quantity by using numeric keys. Eg: 15
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Enter the key to confirm. The scale determines the average parts weight.
As more items are added to the scale, the weight and the count will increase.
If the scale is not stable, the calculation will not be completed.
If the weight is below zero, “Count” display will show negative count.
Enter a known Unit Weight
If already know the unit weight, and then it can enter by using numeric keys.
Enter the value of unit weight by numeric keys.
Press during the unit display flashing.
If in the weight display as “kg” unit is active, the average piece weight will be
displayed in “g”. If as “lb” is active, the average piece weight will be displayed
in “lb”.
Automatic Update of Unit Weight
The scale can automatically update the unit weight, when a sample less than
the initial sample count are added.
A beep will be heard when the value has updated.
By pressing key, can be blocked unit weight and auto update
Check Weighing or Count Pre-set
Check weighing is a procedure to cause an alarm to sound when the weight or piece
quantity within the checking limits. Limits can beset by using numeric keys.
Setting the Checking Limits
Press key, the active mode will be shown
Press key to select counting
Press key, the active high count limit will be shown
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