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.
-4 -
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.
- 5 -
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.
-6 -
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
-8 -
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.
-10 -
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
- 11 -
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
-12 -
Use numeric key to enter desired and if necessary press to clear.
Press key, the active low count limit will be shown
Use numeric key to enter desired and if necessary press to clear.
Press key to return weighing mode.
For check limits, just one limit value can set
If both values are deleted, the check mode is deactivated.
The beep sound will be worked as described in the beep parameter
f1 off , beep
PLU (Product Look Up)
PLU are used to store items. It can store up to 99 PLU numbers.
These data should be entered against a particular PLU before the weighing process
starts, so that the desired PLU’s can be recalled duringthe weighing process. The
data can be stored and recalled manually or by sending data over RS-232 Interface
Storing PLU
Press key to ensure display zero.
Tare and unit weight to be stored can be either taken from a weighing in process or
by enter manually.
Press display will be shown
Press numeric key 2 and 7
Press
Currently stored text will appear
The first digit is flashing, it can
Change by using numeric keys
If necessary, delete additional text
- 13 -
By pressing
Continue to enter text until description is
complete (max: 12 characters)
Use key, number selection to left.
Use key, number selection to right.
Press and hold two seconds key, space to right.
Tare values can be saved when in the admitted taring range(default >2% of
capacity)
Entering Description Manually
To set the description, press the numeric button and keep it pressed until the desired
letter is displayed. The characters are according to key board.
1 - / \
2 A B C
3 D E F
4 G H I
5 J K L
6 M N O
7 P Q R S
8 T U V
9 W X Y Z
0 _ [ ] _ (space)
The characters and the displayed symbols are
A B C D E F G H I J K L
N O P Q R S T U V
X Y Z - / \ ( )
A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 0
Note that this method is only used where alpha-numeric data is permitted. This is used
for the Description field and the User ID number, Scale ID number in the parameters
section.
-14 -
Recalling PLU
To recall the PLU values the user should first select either local or remote scale the tare
value stored will be specific to the scale selected.
Press display will be shown
Press numeric key 2 and 7
Press
PLU’s can be stored and recalled using RS-232 Interface.
- 15 -
5. PARAMETERS
Enter into the Parameter
Turn on the scale, press during that start up.
Display will be shown
Select the Menu Block
Press key, it can choose menu block one by one.
Enter the Selected Menu
Press key, it can confirm which will be shown displayed.
Select the Sub- Menu
Press key, it can choose the sub-menu block one by one.
Return to Weighing Mode
Press key, it can escape from the menu and exit to weighing mode.
-16 -
Parameter Setting
Menu Sub Menu Description
Beep
Beep off
Beep On in
Beeper is turned off
Beeper is turned on, will be
sounded with in the check
weighing limits
Fi off
Beep On out
Beeper will be sounded above the
check weighing limits
El
Lite aut
Backlight will be turn on
automatically, when loaded or key
is pressed
F2 prt
unit
Off
P mode
Lite off
Lite on
Kg / lb Weighing Unit kg and lb are enable
Kilo
lb
0
3
5
15
3 0
Print
Au on
Backlight is turned off
Back light is turned on
Weighing Unit kg only
Weighing Unit lb only
Auto off function disable
Scale will be off three minutes later
Scale will be off five minutes later
Scale will be off 15 minutes later
Scale will be off 30 minutes later
Data out put / accumulation after
unloading the balance
Au off
Data out put / accumulation after
P cont
Ser re
P baud
B 600
B 1200
B 2400
B 4800
B 9600
parity
8 n 1
7 e 1
7 o 1
P type
Tpup
Lp50
U id U id abcdef
Sc id Sc id abcdef
Tech
by pressing
RS 232 data output continuously
RS 232 data output weight only
Set the required baud
8 bits, no parity
7 bits, even parity
7 bits, no parity
Standard printer setting
Tscale Label Printer
Shows the current User ID (max 6
characters)
Shows the current Scale ID (max 6
characters)
Technical parameter password
protected
- 17 -
6. RS- 232 OUT PUT
The QHD Series of scales can be ordered with an option RS-232 output.
Specifications:
RS-232 output of weighing data
ASCII code
4800 Baud
8 data bits
No Parity
Connector: 9 pin socket
Pin 2 Output
Pin 3 Input
Pin 5 Signal Ground
Sample of out put
LOCAL SCALE
ID: 123ABC
NAME:Text
12.456 kg NET
1.1234 g U.W.
11 PCS
TOTAL
- - - - - - - - - - - -
49.824 kg TW
44 TPC
4 No.
Control Commands
-18 -
The scale can be controlled with following commands.
Basic Commands:
PLUxx Select PLU from scale memory
T Tare current weight value
T123.456 Numeric tare value
Z Zero
P Print
M+ Store and print current results
MR Recall memory values to scale display
MC Clear memory
U123.456 Store unit weight of 123.456 kg / lb
S123
Enter sample size of parts 123 . Same as pressing
SL Select local scale to be used
SR Select remote scale to be used
Printing Commands:
\L Scale: Local or Remote
\I User ID number
\S Scale ID number
\N Net weight
\G Gross Weight
\T Tare weight
\U Unit weight
\P Count
\C Total Count
\W Total Weight
\M Number of items stored in memory
\B A blank / space line
PLU entry using RS 232 interface
This will allow the scale data to be sent from a PC program as well as from the keypad.
The most common PLUs can be stored and recalled from the scale memory. Other PLU
data can be stored on a PC, then the text data, unit weight and tare data can be sent
from the PC to PLU00. This can then be used and over written each operation.
OPERATION:
Send tare data to set any tare value to be stored with PLU. i.e. “T0.150” <CR>. If
no tare is needed then you may send T0 to delete any present tare data.
Send the unit weight to be stored with PLU. ie. “U12.3456” <CR>
- 19 -
Send PLU text data to be stored with current TARE and U/W values. ie.
“SPLU01,Parts” <CR>
-20 -
7. CALIBRATION
Turn on the scale and press during the self test.
Use the numeric key to enter password
Default password 0000
Press to confirm
Display will be shown
Select Local or Remote scale by pressing
Press to confirm.
Display will be shown
If necessary, press to select the weighing unit kg or lb.
Press to confirm.
Display will be shown
Ensure the platform is empty and wait for stable indicator.
Press to confirm.
Display will be shown
Set weight value will be required
Enter the value by using numeric keys
Press to confirm.
Display will be shown
Place the calibration weight on the platform and
wait few seconds for display stable.
Press to confirm.
After the calibration scale will start a self test, remove the weight during that time
and display will return to weighing mode.
Incase display will show any error message or incorrect measurement, repeat the
calibration again.
- 21 -
8. TECHNICAL PARAMETER
Enter into the parameter by pressing
during the self test
Press until tech is displayed
Press to confirm, display will be shown
Enter the password. Default password is 0000
and press to confirm
Select the scale by pressing , which
should be configured
and press to confirm
Use the key to select the weighing unit
kg / lb and press to confirm
Use the key to scroll to select individual
menu.
Confirm selected menu by pressing
Press key, escape from the menu and
exit to weighing mode
F1 off
tech
Pi n
Pi n - - - -
Tech local
remote
Tech unit
cnt
-22 -
Technical Parameter Sub Menu Description
Cnt
Cap
Capacity ( For Remote Scale Only )
desc
Sel 001000
I nc
Di v
I nc 5
I nc 10
I nc 20
I nc 50
A 2t
Azn 0 .5d
Azn 1d
Azn 2d
Azn 4d
0 Auto
0 auto 0
0 auto 2
0 auto 5
0 auto 10
0 auto 20
0 manl
0 manl 0
0 manl 2
0 manl 4
0 manl 10
0 manl 50
0 manl 100
Pi n
Pi n 1
Pi n 2
Gra 9. 673 00
0.0
0.00
0.000
10
20
50
Internal counts
0
Set remote scale
decimal point
Set remote scale
capacity by using
numeric keys
1
Set remote scale division
2
5
Set division
Automatic zero tracking
Zero setting range, after
switching on the scales
to zero
Zero setting range, the
display is set to zero by
pressing
Enter new password
Re enter new password
Set local gravity
- 23 -
9. ERROR DISPLAY
Error Message Description Solution
----Err 1
Err 2
Err 4
Err 5
Err 6
Err 9
Maximum load exceeded Unload or reduce weight
Incorrect date Enter the date by using format
“yy;mm:dd”
Incorrect time Enter the time by using format
“hh:mm:ss”
Zero setting error Zero setting range exceeded due
to switching on.(4%max)
Make sure platform empty.
Key board error Check the keys and connecter.
A/D value out of range Make sure platform empty and
check the pan is installed proper.
Check the load cell connectors.
Unstable Reading Check any air variation, vibration,
RF noise and touching some
where.
Check the load cell and
connecters.
Err 17
--ol--
Fai l h /
fai l l
Err p
Ba lo /
lo ba
Tare out of range Remove the load and restart scale
again.
Over range Remove the load.
Re calibrate
Calibration Error Re calibrate
Printer error Check the printer and settings
Battery low Re charge battery, check the
voltages.
-24 -
10. TROUBLE SHOOTING
No Display:
Mains power is turned off or power supply not plugged proper.
Power supply faulty.
Internal Battery is not charged.
Check On/OFF switch is turned on and faulty or not.
Check the PCB power connecters and cable.
Display is Blank after the self test / Err stuck:
Unstable weight.
Check the platform is installed correctly.
Try again to turning on.
Check the load cell is not touching any where.
Load cell is damaged. Check the load cell connections and all.
OL or( -------) appear the display:
Maximum capacity exceeded.
Power supply faulty. Check all power cables and connecters.
Calibrate again with correct calibration weights.
Load cell damaged. Check load cell connections.
(------) or Lo:
Weight is below permissible limit.
Check the pan installed correctly.
Calibrate again with correct calibration weights.
Power Supply faulty. Check all power cables and connecters.
Load cell damaged. Check load cell connections and connecters.
Try to turn on again.
Unstable display:
Check the pan is seated proper and touching some where
Check any vibrations, noises, sudden temperature changes.
Check power supply.
- 25 -
Check battery and connect to charging.
Check the load weight is seated properly.
Check the load cell connections and connecters.
Incorrect value:
Calibration error.
Calibrate again with exact calibration mass weights.
Check the weight sample is lying proper and avoids touching the cover or
surface.
Check power supply and battery.
Check load cell connections and connectors.
Can not use scale full capacity:
Before weighing make sure zero indication is showing and scale is empty.
Check the weighing mode.
Check the load cell is fitted proper and touching housing or hitting somewhere.
Calibrate again with exact calibration mass weights.
Load cell damaged. Check load cell connections and connectors.
Main PCB problem.
Battery not charging:
Mains voltage problem. Check the power supply voltage and adaptor voltage.
Charging circuit failure.
Battery failure, check the battery connections
-26 -
11. MAINTENANCE
Disconnect the power before cleaning.
Use a cloth with mild suds and light cleaning agents. Make sure that fluid is not able to
get into the device. Use a clean and soft cloth for remove.
This devise does not require any routine maintenance. It may be necessary to perform
periodic checks of the calibration of the scale due to mechanical reasons. The frequency
of the checks depends on the conditions to use.
CHANGE PARTS
1. Replace main board
Remove adaptor pin fromthe jack.
Remove the pan.
Remove the five screws from the bottom of
housing, securing the front and back halves of the
cover.
Disconnect the power connector, display connector
and load cell cable.
Disconnect the ground cable from the main
PCB
Remove the main PCB
from the back cover.
Carefully remove the main PCB and keep on a
protective place.
Install a new main PCB.
Connect load cell cable, display connector, ground
cable and power connecter.
Close the top cover to the bottom cover with the
five screws.
- 27 -
2. Replace display board
Remove the top cover
Remove the seven screws from the display board and clean the glue.
Disconnect the key board connecter and main PCB connecter from the display
board.
Remove the display board.
Install a new display board.
Connect the key board connecter and main
PCB connecter.
Turn on the power and check the working condition. Then, turn off the power.
Fix the seven screws and apply glue.
Close the top cover.
3. Replace load cell
Open the top cover.
If necessary remove the PCB’s for avoid damage.
Disconnect load cell connections from the PCB.
Remove the four foots from the bottom cover.
Remove the four screws from the upper bracket.
Remove the bracket
with load cell from the cover.
Bracket set place on the table.
Remove the allen screws from the top
and bottom brackets by using 5mm allen
key.
Load cell will get separate from the
bracket.
Install the new load cell.
Fix the brackets proper.
Fix whole bracket to the bottom cover by using four
screws.
Fix the four foots to the bottom cover.
Connect the load cell connections to the main PCB.
Fix all PCB’s and cables proper.
Close the top cover.
Remove the pan and dust cover.
Open the battery cover from the top cover.
-28 -
4. Replace battery
Take it out the battery from in side the housing.
Remove the connecters from the battery terminals.
Change the new battery.
Connect the connecters to the battery terminals.
Battery, place it proper to inside the housing.
Close the battery cover.
Fix the dust cover and pan.
Checking Components
Remove the pan
Open the housing.
Make sure components all are clean.
Check the connectors are connected proper.
Check the keyboard.
Check the display board and main PCB.
Check the load cell
Check the battery
If any component damaged replace it.
Close the housing.
Install the pan and check its lying proper there.
Checking Load cell
Remove the top cover from the scale.
Remove power connecter from the main board.
Make sure load cell cable connections are proper and no insulation material is
touching the terminal contacts.
Check load cell bridge resistance.
Load Cell Connections:
Signal + Green
Supply + Red
Signal - White
Supply - Black
- 29 -
Shield
Points Resistance
Red (+E) to Black (-E) 406 ohms ± 6 ohms
Green (+S) to White (-S) 350 ohms ± 3 ohms
If proper excitation voltage is reaching the load cell, check the output signal.
If load cell has an unusual signal, replace that load cell.
Checking Voltages
Using a multimeter, check the mains voltage.
Check the adaptor is outputting a voltage 9 VDC.
Check PCB input voltage 9VDC.
Check battery voltage of at least 6 VDC.
-30 -
12. CIRCUIT DIAGRAM
- 31 -
-32 -
13. DRAWING
- 33 -
Parts List
No Parts Name Qty Material Spec
1 Pan 1 SST 230mmx300mm
2 Pan 1 ABS 230mmx300mm
3 Battery cover 1 ABS
4 Battery 1 Lead Acid 6V/4Ah
5 Foam 1 CR
6 Rear Overlay 1
7 Top Cover 1 ABS
8 Name Plate 1
9 Internal Allen Screw 4 M6x16, 8.8
10 Washer (M6) 4 65Mn 200-300HV
11 Spring Washer(M6) 4 HRC42-50
12 Load cell upper bracket 1 Aluminum
13 Load cell 1 Aluminum Alloy
14 Star (+) Screw 4 20Mn M4x16
15 Load cell lower bracket 1 Aluminum
16 Self thread Screw 4 S18C 4x10
17 InsulativeWasher 4 EDPM 8x3.1x1.2t
18 Power Socket 1
19 Power Socket Spacer 1 PC
20 Power Switch 1
21 Foot 4 PVC
22 Key board 1
23 Front display overlay 1
24 Level bubble 1 14.7mm
25 Screw 1 M4x35
26 Front Display PCBA 1
27 Insulative Washer 5 EDPM 8x3.1x1.2t
28 Star (+) Self thread screw 5 20Mn M3x20
29 Star (+) Self thread screw 5 20Mn M4x20
30 Hexagon Nut 4 Zn Coating
31 Main PCBA 1
32 Screw for D connector 4
33 D type connector 2
34 Hexagon nut for D connector 4
35 Overlay 1
36 Bottom Cover 1 ABS
37 Self thread screw 5 20Mn 4x12
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14. SPECIFICATIONS
DIMENSION
Specification
MODEL QHD+ 3 QHD+ 6 QHD+ 15 QHD+ 30
Maximum Capacity 3000 g 6000 g 15 kg 30 kg
Readability 0.05 g 0.1 g 0.2 g 0.5 g
Tare Range -3 kg -6 kg -10 kg -30 kg
Repeatability(Std Dev) 0.05 g 0.1 g 0.2 g 0.5 g
Linearity ± 0.1 g 0.2 g 0.5 g 1 g
Units of Measure lb, kg
Interface Bi-directional RS-232 Interface
Stabilization Time 2 Seconds
Operating Temperature 0°C - 40°C (32°F- 104°F)
Power supply AC Adaptor 9 V/800 mA / Battery 6V4AH
Calibration Automatic external
Display 3 x 6 digits LCD digital display with white LED back
light
Housing Indicator ABS Plastic, Stainless Steel pan
Pan size 225 x 300mm / 8.9 x 11.8”
Overall dimensions 320 x 340 x 125mm / 12.6 x 13.4 x 4.9”
Net weight 4.3kg / 9.5lb
Applications Counting Scale
Internal Resolution Up to60000
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Specification for Remote Scale
Excitation voltage 5 VDC
Signal range 0-20 mV(allows 3 mV/V LC with 5mv zero offset)
Zero range 0-5 mV
Sensitivity 0.02 µV/internal ADC count or better
Internal ADC counts 500,000 maximum at 10 mV input
Load 87 ohm minimum, 4 X 350 ohm load cells
Connection 4 wire connection to load cells plus shield
Maximum cable length 6 meters
Termination 9 pin d-subminiature plug on scale
Specification for Local Scale Load Cell
Model No C2X1
Rated Capacity 6~50 (kg)
Rated Out put 2.0 mV/V±0.2 mV/V
Excitation Voltage 20 VDC
IP Level IP64
Material Aluminum Alloy
Cable Φ8.2 four core shield
Input Resistance 420Ω±30Ω
Out put Resistance 350 Ω± 5 Ω
Temperature
-10°C - 50°C
Range
Safe overload 150 %R.C
Ultimate overload 200 %R.C
Repeatability 0.02 %R.O
Creep 0.02 %R.O/ 20min
Zero Balance ± 0.1 mV/V
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Intelligent Weighing Technology has more than 50 years experience in the weighing industry, both in the USA and
worldwide. With contacts in over 50 countries including the USA, we provide you with the weighing equipment you need.
When you invest in weighing equipment from Intelligent Weighing Technology, you’re really buyingpeaceof mind.
Quality - Scales and balances solidly built from the ground up with superior engineering and components for exacting results.
Value - From bench scales to analytical balances, weighing equipment priced for real-world business applications, with superior
service and support.
Experience - Expert advice to help you choose just the right product for your application.
Quality + Value + Experience…it adds up to the Intelligent Investment.
Intelligent Weighing Technology, Inc.
www.intelligentwt.com
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