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300 g x 0.01 g
DIGITAL BALANCE
Model : GM-300P
Your purchase of this DIGITAL BALANCE marks a step forward
for you into the field of precision measurement. Although this
DIGITAL BALANCE is a complex and delicate instrument, its
durable structure developed. Please read the following
instructions carefully and always keep this manual within easy
reach.
OPERATION MANUAL
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TABLE OF CONTENTS
1.FEATURES............................................................1
2.SPECIFICATIONS.................................................
.
1
3. FRONT PANEL DESCRIPTION................................3
3-1 Platform.......................................................
.
3
3-2 Level Bubble.................................................
.
3
3-3 CAL. Button ( function A Button )...................
.
3
3-4 Tare Button ( function B Button )...................
.
3
3-5 Display.........................................................
.
3
3-6 Power Switch................................................ 3
3-7 Rubber Pads.................................................
.
3
3-8 Battery Cover/Compartment...........................3
3-9 DC 9V Receptacle..........................................3
3-10 RS232 Output Socket....................................3
3-11 Unit Switch..................................................
.
3
4.PLATFORM INSTALLATION...................................
.
4
5.WEIGHT MEASURING PROCEDURE........................5
6.SELF-CALIBRATION..............................................6
7.COUNTING SCALE OPERATION PROCEDURE..........8
8.BATTERY REPLACEMENT......................................
.
10
9.DC 9V AC/DC ADAPTER OPERATION.....................
.
10
10. RS232 PC SERIAL INTERFACE.............................10
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1. FEATURES
* Microprocessor circuit with high accuracy & better
performance.
* 0.01
g
& 0.0005 oz resolution & wide measuring capacity.
*Lar
g
e LCD display, 20.9 mm ( 0.8" ) digit size, easy read out.
* Built-in
g
ram & oz display unit, select by the internal
slide switch.
* Built-in self calibration system, the calibration value can
memorize into EEPROM circuit permanently even power
off.
*Hi
g
h precision counting scale function.
* RS-232 computer interface.
* Accept battery or AC/DC adapter power source, two way
power supply.
* Built-in " level bubble " & the ad
j
ustable " rubber pads ".
* Heavy duty ABS housin
g
plastic case.
2. SPECIFICATIONS
Display LCD, 20.9 mm ( 0.8" ) digit size, 5 digits
with annunciator.
Measuring range
&
UnitRan
ge
Resolutio
n
Resolution
g
0.10 g to 300
g
0.01 g.
oz 0.005 oz to 9.9995 oz 0.0005 oz
10.000 oz to 10.582 oz 0.001 oz
Min. Display Weight
g
0.10
g
oz 0.005 oz
Unit Select
g
or oz, select by internal slide switch.
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Accuracy ( 0.05 % + 0.04 g )
*Within two hours after self calibratio
n
be executed.
23± 5 .℃
*
Spec. tested under the environment R
F
Field Strength less than 3 V/M
&
frequency less than the 30 MHz only.
Sampling time Approx. 1 second.
Tare Control Approx. 300 g max.
Transducer Load cell.
Circuit Microprocessor circuit.
Auto Calibration Use 100 g or 200 g standard weight to
execute self-calibration automatically.
Operating 0 to 50 ( 32 to 122 ).℃℃℉ ℉
Temperature
Operating Humidity Less than 80% RH.
Size Cabinet 250 x 190 x 70 mm
Platform Round, 120 mm Dia.
Power Supply 1.5V AA (UM-3) battery x 6 PCs,
or DC 9V adapter, optional.
Power Consumption Approx. DC 17 mA.
Accessory Included Operation Manual........1 PC.
Optional * Software ( Windows version ),
accessories SW-U801-WIN, SW-E802.
* RS232 cable, UPCB-02.
* USB cable, USB-01.
* 200
g
calibration weight, WT-200.
* AC/DC 9V power adapter, AP-9VA.
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3. FRONT PANEL DESCRIPTION
Side view Bottom view
Front view Back view Fig. 1
3
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3-1 Platform
3-2 Level Bubble
3-3 CAL. Button ( function A Button )
3-4 Tare Button ( function B Button )
3-5 Display
3-6 Power Switch
3-7 Rubber Pads
3-8 Battery Cover/Compartment
3-9 DC 9V Receptacle
3-10 RS232 Output Socket
3-11 Unit Switch
4. PLATFORM INSTALLATION
Fig. 2
4
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5. MEASURING PROCEDURE
As intend to let the balance under the best operatio
n
condition, it recommend to warm up the balance at leas
t
30 minutes before make the operation.
1) Place the balance on a flat hard surface.
Ad
j
ust the " Rubber Pad " ( 3-7, Fig. 1 ) until the water
bubble of the " Level Bubble " ( 3-2, Fi
g
. 1 ) on the center
position, then the scale already install under the
horizontal position completely.
2) Set the "
g
" or "oz" unit by slide the " Unit Switch "( 3-11, Fig. 1 ).
* The scale are set to the " g " unit typically.
* Use the "-" type screw driver to slide the " Unit Switch ".
* Slide the " Unit Switch " to the ri
g
ht position will set t
o
" gram " unit & the right down corner of LCD will show th
e
" g " marker.
* Slide the " Unit Switch " to the left position will set t
o
" oz " unit.
3) Turn the " Power Switch " ( 3-6, Fig. 1 ) to the " On " position.
1 = On, 0 = Of
f
The " Display " ( 3-5, Fig. 1 ) will show " 8.8.8.8.8 " for a few
seconds, then " 0 " value ( 0.00
g
for gram function, 0.0000
for oz function ) will be present.
4) Apply the load to the platform
g
ently, display will show
the measurin
g
weight values.
* Do not exceed the over load capacity of the scale.
* Over wei
g
hting, the display will show " - - - - - ".
5) Tare function :
After wei
g
hting the first item, press " Tare Button " ( 3-4,
Fi
g
. 1 ), scale will reset to zero values automatically.
At the same time, the LCD display will show the " TARE "
mark. Place next wei
g
hted item onto scale. Scale will
g
ive weights of the second only.
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Consideration of tare functio
n
*
If the display show minus weight or show "_ _ _ _ _
"
means the display reading is under the zero, the
n
tare function should be executed.
*
Before measuring the weight, If the display is no
t
zero & show some value, it means the internal circui
t
is over the zero, then tare function should b
e
executed.
*
T
he max. tare capacity is approx. 300 g.
*
T
he " Tare " marker will disappear until power of
f
and power on again.
6. SELF-CALIBRATION
1) Please prepare the following optional " Standard Weight " :
200 gram standard weight (WT-200, optional).
or
100 gram standard weight.
2) Calibration under the 200 gram standard weight
a) Power on the scale until the display show zero value.
Apply the 200
g
ram standard weight to the center of the
platform
g
ently. If the scale is not accurate, then may
show the wei
g
ht value around 200 g ( for example 199.93
g
, 200.06 g.....)
b)
Step 1 :
Press the " CAL. Button " ( 3-3, Fig. 1 ) once,
display will show the value of " 100.00
g
"
Step 2 :
Following press the " Tare Button " ( 3-4, Fig. 1 ) once,
display will show the value of " 200.00
g
"
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Step 3 :
Press the " CAL. Button " ( 3-3, Fig. 1 ) once again,
display value of " 200.00
g
" will flash 6 times, then the
calibration procedures are finished completely & balance
is ready for the measurement accurately.
3) Calibration under the 100
g
ram standard weight
a) Power on the scale until the display show zero value.
Apply the 100
g
ram standard to the center of the
platform
g
ently. If the scale is not accurate, then may
show the wei
g
ht value around 100 g ( for example 99.94
g
, 100.05 g.....)
b)
Step 1 :
Press the " CAL. Button " ( 3-3, Fig. 1 ) once,
display will show the value of " 100.00
g
"
Step 2 :
Press the " CAL Button " ( 3-3, Fig. 1 ) once again,
display value of " 100.00
g
" will flash 6 times, then the
calibration procedures are finished completely & balance
is ready for the measurement accurately.
Consideration of Self-Calibration
:
* The internal Self-Calibration value is saved to th
e
internal EEPROM circuit permanently. Once power off the
n
power on, the calibration value will be not disappeared .
* After make the self calibration, measure the 100
g
or 200
g
standard weight again, if the display value existing few
counts deviation, it is normal. However within few hours,
the balance will be kept under a hi
g
h accuracy condition.
T
hose accuracy will be even better than the published
specification ( refer pa
g
e 2 ).
* Under the status of " oz " unit, still can use the wei
g
ht o
f
100 g or 200 g to make the calibration. However the " g
"
marker will disappear.
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7. COUNTING SCALE OPERATION
PROCEDURE
1) Prepare a lot of counting sample units. The no. o
f
counting sample will be 10 PCs, 20 PCs, 50 PCs or 100
PCs.
The more PCs of countin
g
sample will be better.
*No load to put on the platform.
2) Use the finger to hold the " CAL. Button ( function
A
Button ) " ( 3-3, Fig. 1 ), at the same time set the
" Power Switch " ( 3-6, Fi
g
. 1 ) to the " On " position.
Until one beeper sound is present, then release the
fin
g
er away from " function A Button ".
3) a. The bottom left corner of LCD will show the
" COUNT " marker, at the same time the LCD will
show no. of sample units from 10, 20, 50, 100 in
sequence & chan
g
ed per second.
b. Put the countin
g
sample units ( For example 10 PCs,
20 PCs, 50 PCs or 100 PCs ) on the platform.
c. Until the display reach the no. of sample units
exactly, for example " 50 ", push the " function
A
Button " ( 3-3, Fig. 1 ) once a while. The display
will flash twice and freeze the sample countin
g
no.,
then take away the sample units. Now the
balance is ready for countin
g
.
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Change to the new counting sample units
Under the counting version if intend to change the
countin
g
sample units, the new procedures are following :
a. Take away any load from the platform.
b. Push the " function A Button " ( 3-3, Fi
g
. 1 ) once a
while. LCD will show no. of sample units from 10, 20,
50, 100 in sequence & chan
g
ed per second.
c. Put the countin
g
sample units ( For example 10 PCs,
20 PCs, 50 PCs or 100 PCs ) on the platform. Until the
display reach the no. of sample units exactly, for
example " 50 ", push the " function A Button " ( 3-3,
Fi
g
. 1 ) once a while again. The display will flash
twice and freeze the set countin
g
no., then take away
the sample units. Now the balance is ready for countin
g
& the sample counting units already change to new
value.
Consideration
:
@
Under the counting function, 1 PC weigh
t
should large than 0.50 g, other wise the resul
t
of counting no. may existing some error.
@
The accuracy for the " counting no. " result ar
e
always depend on the no. of " sample units " tha
t
key in. We strong recommend that it can tak
e
more sample units as possible, for example 5
0
PCs or more, then will get the best accuracy.
4) a. Take away the counting sample units away from
the platform, then put the new lot of units that
intend to be counted on the platform.
b. The display will show the countin
g
no. of the new
" sample units ".
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8. BATTERY REPLACEMENT
If battery is weak, LCD display will show " LO " indicator.
Every 1 second the " LO " indicator will flash one time.
This reminds user to replace new battery.
1) Open " Battery Cover " ( 3-8, Fi
g
. 1 ) located at the bottom
of the scale.
2) Accordin
g
to the device instruction, place batteries ( 1.5V
AA size battery x 6 PCs ) into the battery compartment
&
replace the battery cover.
9. DC 9V AC/DC ADAPTER OPERATION
(Adapter is optional accessory)
1) The scale will also be operated by the household ACV
power source (110/220/240 ACV) with a DC 9V
Adapter ( capacity 300 mA).
2) Plug the jack from the Adapter into the " DC 9V
receptacle " ( 3-9, Fig. 1 ).
3) Now the scale is ready for ACV operation.
10. RS232 PC SERIAL INTERFACE
The instrument features an RS232 output via 3.5 mm
Terminal ( 3-10, Fi
g
. 1).
The connector output is a 16 di
g
it data stream which can be
utilized to the user's specific application.
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An RS232 lead with the following connection will
be required to link the instrument with the PC
serial input.
Scale PC
(3.5 mm jack plug) (9W 'D" Connector)
Center Pin........................................ Pin 4
Ground/shield......................................Pin 2
2.2 K
resistor
Pin 5
The 16 digit data stream will be displayed in the following
format :
D15 D14 D13 D12 D11 D10 D9 D8 D7 D6 D5 D4 D3 D2 D1 D0
Each digit indicate the following status :
D15 Start Word
D14 4
D13 1
D12, D11 Annunciator for Display
g
= 57
oz = 58
count = 30
D10 Polarity
0 = Positive 1 = Ne
g
ative
D9 Decimal Point(DP), position from right to the left
0 = No DP, 1= 1 DP, 2 = 2 DP, 3 = 3 DP
D8 to D1 Display reading, D1 = LSD, D8 = MSD
For example :
If the display readin
g
is 1234, then D8 to D1 is :
0000123
4
D0 End Word
RS232 FORMAT : 9600, N, 8, 1
Baud rate 9600
Parity No parity
Data bit no. 8 Data bits
Stop bit 1 Stop bit
11
1109-GM300P
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