GW Instek GOM-802 User manual

Declaration of Conformity
We
GOOD WILL INSTRUMENT CO., LTD.
No. 95-11, Pao-Chung Rd., Hsin-Tien City, Taipei Hsien, Taiwan
GOOD WILL INSTRUMENT (SUZHOU) CO., LTD.
No.69 Lushan Road, Suzhou New District Jiangsu, China.
declare that the below mentioned product
GOM-802
is herewith confirmed to comply with the requirements set out in the Council Directive on
the Approximation of the Law of Member States relating to Electromagnetic Compatibility
(89/336/EEC, 92/31/EEC, 93/68/EEC) and Low Voltage Equipment Directive
(73/23/EEC).
For the evaluation regarding the Electromagnetic Compatibility and Low Voltage
Equipment Directive, the following standards were applied:
◎EMC
EN 61326-1: Electrical equipment for measurement, control and laboratory use –– EMC
requirements (1997+A1: 1998)
Conducted and Radiated Emission
EN 55011: 1998 class B Electrostatic Discharge IEC 61000-4-2: 1995+A1: 1998
Current Harmonic
IEC 61000-3-2: 2000 Radiated Immunity IEC 61000-4-3: 1996+A1: 1998
Voltage Fluctuation
IEC 61000-3-3: 1995 Electrical Fast Transients IEC 61000-4-4: 1995
------------------------- Surge Immunity
IEC 61000-4-5: 1995
------------------------- Conducted Susceptibility
IEC 61000-4-6: 1996
------------------------- Power Frequency Magnetic Field
IEC 61000-4-8: 1993
------------------------- Voltage Dips/ Interrupts
IEC 61000-4-11: 1994
◎Safety
Low Voltage Equipment Directive 73/23/EEC & amended by 93/68/EEC
IEC / EN 61010-1: 2001
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CONTENTS PAGE
1. PRODUCT INTRODUCTION...............................................……
1-1. Description…………………………………………………………..
1-2. Key Feature……………………………………………..…………..
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2
2. SPECIFICATIONS………………...…………………………… 4
3. PRECAUTIONS BEFORE OPERATION…….………….…...
3-1. Unpacking the Instrument...…………….………….……………....
3-2. Checking the Line Voltage………………..………………………...
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4. PANEL INTRODUCTION……………………..………….…...
4-1. Front Panel……………………………………………………….…
4-2. Rear Panel……………………………………….…………………..
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5. OPERATION INTRODUCTION...……………………...……..
5-1. The [SHIFT] key and function keys………………..….…………...
5-2. Warm up…………………..………………………………………..
5-3. Over-range indicator…..……………………………………………
5-4. TRIG standby indication…………………………………………...
5-5. Input overload protection.….…………………………..…………..
5-6. Interface Operation…….…………………………………………..
5-7. Installation and Operation………………………………………….
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6. MEASUREMENT INSTRUCTION……………………………
6-1. Resistance measurement……………………………………………
6-2. Temperature measurement………………………………………...
6-3. Temperature Compensation Measurement………………………..
6-4. General Function……………………………………………………
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7. MEASUREMENT TECHNIQUES…………….………………
7-1. 4-wire measurement………………………………………………..
7-2. Temperature measurement………………………………………...
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8. MAINTENANCE………………………………………….…….
8-1. Line fuse replacement……………………………….……………...
8-2. Line voltage conversion…..…………………………..…………….
8-3. Cleaning……………………………………………………………..
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SAFETY TERMS AND SYMBOLS
These terms may appear in this manual or on the product:
WARNING. Warning statements identify condition or
practices that could result in injury or loss of life.
CAUTION. Caution statements identify conditions or
practices that could result in damage to this product or
other property.
WARNING: This equipment is not for measurements
performed for CAT II, III and IV.
The following symbols may appear in this manual or on the product:
DANGER ATTENTION Protective Earth(ground)
High Voltage refer to Manual Conductor Terminal
Terminal
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FOR UNITED KINGDOM ONLY
NOTE: This lead/appliance must only be wired by competent persons
WARNING: THIS APPLIANCE MUST BE EARTHED
IMPORTANT: The wires in this lead are colored in accordance with
the following code:
Green/ Yellow: Earth
Blue: Neutral
Brown: Live (Phase)
As the colors of the wires in main leads may not correspond with the
colors marking identified in your plug/appliance, proceed as follows:
The wire which is colored Green & Yellow must be connected to the
Earth terminal marked with the letter E or by the earth symbol
or colored Green or Green & Yellow.
The wire which is colored Blue must be connected to the terminal
which is marked with the letter N or colored Blue or Black.
The wire which is colored Brown must be connected to the terminal
marked with the letter L or P or colored Brown or Red.
If in doubt, consult the instructions provided with the equipment or
contact the supplier.

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This cable/appliance should be protected by a suitably rated and
approved HBC mains fuse: refer to the rating information on the
equipment and/or user instructions for details. As a guide, cable of
0.75mm2should be protected by a 3A or 5A fuse. Larger conductors
would normally require 13A types, depending on the connection
method used.
Any mounded mains connector that requires removal /replacement
must be destroyed by removal of any fuse & fuse carrier and disposed
of immediately, as a plug with bared wires is hazardous if a engaged
in live socket. Any re-wiring must be carried out in accordance with
the information detailed on this label.
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1. PRODUCT INTRODUCTION
1-1. Description
GOM-802 is a high precision programmable DC Milli-ohm meter suitable
for the low resistance measurements of switches, relays, connectors, PCB
tracks and variety of other devices. With the easy-to-use features, superior
performance, and automatic test interfaces described as below, GOM-802 is
obviously a reliable and handy instrument for the low resistance
measurements.
Easy-to-use features:
Utilizing the arrow key for setting the percentage of upper and lower limit based on
the normal value can make it easier to execute the HI-LO-GO comparator function.
Besides, through the Alarm Buzzer setting can indicate the PASS/FAIL status, and
all kinds of output status can be indicated through Handler Interface output.
The RELATIVE feature that enables GOM-802 to remove the stray resistance easily,
and the 20 sets of Normal/Hi/Lo setting memories can satisfy with different kind of
test condition. Also, the last setting will be recalled every time when the GOM-802
is turned on.
Superior Performance:
There are nine measurement ranges from 30mΩto 3MΩselected automatically or
manually with the constant current between 1μA and 1A, 0.05% high accuracy,
1μΩ resolution and four terminals Kelvin connection to make a reliable and
consistent test result.
The flexible choice for a high measurement accuracy at speed of 7 sampling/sec
(full scale at 30000) or a less measurement accuracy at speed of 30 sampling/sec
(full scale at 3000) can match with the speed requirement of test.

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Temperature Compensation (Option):
The optional temperature probe PT-100 can control the measuring resistance to meet
the required temperature. When the temperature coefficient and required
temperature is keyed in under TC mode, GOM-802 will display the measuring
resistance corresponding to the required temperature.
Automatic Test:
For automatic system applications, the GOM-802 provides a handler interface that
can indicate the output status on PASS, FAIL, HI, LO, READY, or EOT, and
control signal of measurement trigger. An optional RS-232 GPIB is also available
for the computer control application.
Application:
zProduction testing for contact resistance of switches, relays, connectors,
cables and printed circuit boards and other low resistance devices.
zComponent testing of resistors, motors, fuses, heating elements.
zIncoming inspection and quality assurance testing.
zConductivity evaluation for product design.
1-2. Key Feature:
z30,000 counts.
zMeasurement Range: 30mΩ~3MΩ.
z0.05 high accuracy.
zHi/Lo comparator and limit percentage setting with 20 memory sets.
zMeasurement of REL, Actual and % value.
zManual or Auto-ranging.
zContinuous or Trigger measurement mode.
zTemperature compensation and measurement.
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zFour-wire measurement method.
zAuto-recall last setting on re-power on.
zDiode test.
zAlarm setting for PASS/FAIL test result.
zSampling rate: 7 or 30 sampling/sec.
zStandard interface: Scan, Handler, optional interface: RS-232 GPIB.

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2. SPECIFICATIONS
The specifications are operated under the essential conditions as follows:
zA 1-year calibration cycle.
zAn operating temperature of 18 to 28℃(64.4 to 82.4℉).
zRelative humidity not exceeding 80%.
zAccuracy is expressed as ±(percentage of reading + digits).
zThe instrument requires 30 minutes warm-up time to achieve rated
accuracy.
1. Resistance Measurement
30000 counts (speed : 7 times/second)
Range Resolution Measuring
Current Accuracy Open-terminal Voltage
30m 1μ1A approx. 0.1%+6*
300m 10μ100mA 0.05%+6*
3 100μ100mA 0.05%+3
30 1m 10mA 0.05%+2
300 10m 1mA 0.05%+2
3k 100m 100μA0.05%+2
3V
30k 1 100μA0.05%+2
300k 10 10μA0.05%+2
3Meg 100 1μA0.05%+2 4.8V
3000 counts Accuracy
(speed: 30 times/second) ±5 counts **
*When the instrument is set to 30mΩor 300mΩrange, the resistance value will
be changed while connecting or disconnecting the test lead to the panel due to the
different temperature between internal and external of the instrument. Therefore,
it must wait 1 minute in order to obtain an accurate value after the test lead is
connected or disconnected.
* When use Kelvin clip to resume testing after long time ending, it needs more
time to wait for a stable value.
** In high speed mode, first assure that the instrument has been grounded throug
h
power cord.
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Measurement Four-terminal method.
Auto-ranging Provided.
Over input range“OL”indication
Maximum Applied voltage 30m~3Ωrange: 30VpDC
Other range: 100VpDC
Comparator 20 sets of comparator status can be selected.
Buzzer mode switchable NON, PASS, FAIL
2.Temperature Measurement
Temperature sensor (option) Platinum resistor.
Lead length: 1.5m approx.
Range Accuracy
Speed: 7 times/second Accuracy Speed: 30 times/second
-9.9℃~ 39.9℃0.3%+0.5℃0.3%+2℃
-50.0℃~ -10.0℃
40℃~ 100℃0.3%+1.0℃0.3%+3℃
3. Temperature Correction Function
Temperature correction range 0.0℃~40.0℃
Reference temperature range 0℃~99.9℃
Thermal coefficient range ±9999 ppm
Temperature range Accuracy of temperature compensation for
3930 ppm/Cu wire, speed: 7 times/second.*
0℃~39.9℃0.3%+resistance measurement accuracy.
40℃~100℃0.6%+resistance measurement accuracy.
* The temperature coefficiency for the other setting must be calculated individually
according to different conditions.
* If the temperature coefficiency or the difference between the environmental
temperature and the require temperature exceeds normal operation, after
compensation calculation, the variation of the reading value will be tremendous.

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4. Interface
Handler interface
Signal: START TTL input
Signal: LOW, HIGH, FAIL, PASS, EOT, READY
total 6 TTL outputs.
(This function is valid only under the resistance
measurement mode and the compare mode is
enabled.)
Scanner
Signal: READY, PASS, LOW, HIGH, CLOCK,
STRB total 6 TTL outputs.
(This function is valid only under the resistance
measurement mode and the compare mode is
enabled.)
RS-232 GPIB (option) IEEE488.1-1987, IEEE488.2-1992 and SCPI-1994
5. ENVIRONMENTAL
Operation
Environment
Indoor use, altitude up to 2000m.
Ambient Temperature 0℃to 40℃.
Relative Humidity 80% (Maximum).
Installation category II
Pollution Degree 2
Storage temperature -10℃to 70℃.
6. GENERAL
Power source AC 100V/120V/220V/230V±10%, 50/60Hz, 27VA,
22W.
Accessories Test Lead × 1, Instruction manual × 1,
Programmable manual × 1 (option),
Temperature sensor (option) × 1
Dimension 251(W)×91(H)×291(D) m/m
Weigh Approx. 3 kg
WARNING：To avoid electrical shock, the power cord
protective grounding conductor must be connected to ground.
CAUTION：To avoid damaging the instrument, do not use it
in a place where ambient temperature exceeds 40℃.
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3. PRECAUTIONS BEFORE OPERATION
3-1.Unpacking the Instrument
The product has been fully inspected and tested before shipping from the factory.
Upon receiving the instrument, please unpack and inspect it to check if there is
any damage caused during transportation. If any sign of damage is found, notify
the bearer and/or the dealer immediately.
3-2.Checking the Line Voltage
The product can be applied by any kind of line voltages shown in the table below.
Before connecting the power plug to an AC line outlet, make sure the voltage
selector of the rear panel is set to the correct position corresponding to the line
voltage. It might be damaged the instrument by connecting to the wrong AC line
voltage.
WARNING. To avoid electrical shock the power cord protective
grounding conductor must be connected to ground.
AVERISS: Pour éviter les chocs électriques, le fil de terre du
cordon secteur doit impérativement être relié à la terre.
When line voltages are changed, replace the required fuses shown as below:
Model Line
voltage Range Fuse Line
voltage Range Fuse
GOM-802 100V
120V 90-110V 108-132V TT0.3A 250V 220V 230V 198-242V 216-250V T0.25A 250V
WARNING. To avoid personal injury, disconnect the power cord
before removing the fuse holder.

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4. PANEL INTRODUCTION
Figure 4-1. Front Panel
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Figure 4-2. Rear Panel

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4-1. Front Panel
1. Interface Indicator
2. Normal value displayed area.
3. Comparator indicator.
4. Upper limit percentage display area.
5. Low limit percentage display area.
6. Measurement value displayed area.
7. Functions control indicator.
8. Measurement terminal: Sense HI, Sense LO
9. Current source terminal: Source HI, Source LO.
10. The negative measurement terminal has the same potential as the
circuit earth terminal, but can not be replaced by it.
11. Function Control knob.
WARNING: This equipment is not for measurements
performed for CAT II, III and IV.
4-2. Rear Panel
12. GPIB Interface terminal.
13. RS232 Interface terminal.
14. Handler and SCAN interface terminal.
15. Temperature compensation probe terminal (TC SENSOR).
16. Line voltage selector and input fuse holder.
17. AC Power-line connector.
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5. OPERATION INTRODUCTION
5-1. The [SHIFT] key and function keys
The [SHIFT] button is used to enable the secondary function of certain
function keys that with blue symbols printed above. The SHIFT LED will
be on after pressed the [SHIFT] button. At this time, only the buttons with
blue symbols are workable. To release SHIFT function, press [SHIFT]
again.
5-2. Warm up
The instrument requires half-an-hour warm up to achieve rated accuracy.
5-3. Over-range indication
If the input exceeds the full scale of the selected range, the instrument will
indicate over-range input by lighting the “OL” message on the display.
5-4. TRIG standby indication
Under the TRIG mode, change the range or power on the instrument, the
“————” message will be displayed on the measurement displayed area,
now the instrument is in the TRIG standby status. The decimal is
represented the range. When proceeding the TRIG measurement, the
measurement displayed area will display the present measuring value.
5-5. Input overload protection
The maximum allowable input is shown as table 5-1. Please proceed the
measurement accordingly.
Table 5-1:
RANGE MAXIMUN INPUT
30mΩ, 300mΩ,3Ω30Vp DC
Other ranges 100Vp DC
WARNING: To avoid shock hazard and/or instrument
damage, do not apply input potentials that exceed the input
overload limits shown in table 5-1.

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5-6. Interface Operation
This instrument equips RS-232 as standard device with a D-SUB 9 PIN
SHELL on the rear panel. Besides, the instrument also provides a GPIB
option device with a 24 PIN SHELL in blue. The configuration is
compliance with IEE488.
For further detailed operation, please refer to the Interface manual.
5-7. Installation and Operation
Operate the GOM-802 in a location with a suitable environment free from
dust, direct exposition of sunlight, and strong effect of magnetic fields.
If you have no idea about the resistor value before testing, start from the
high resistor value range to the low until the right value can be read out.
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6. MEASUREMENT INSTRUCTION
6-1. Resistance measurement
(1) Resistance measurement function
1) Get into resistance measurement function by pressing [SHIFT] and
[TEMP] in sequence to select main function mode.
2) Press [▲]or[▼] can switch over the function, and 3 kinds of
measurements “ohm”, “℃” and “TC” will be displayed on the panel.
3) Press “ohm” and [ENTER] to get into resistance measurement
mode.
4) Use [▲]or[▼] to switch to adequate range or press [AUT/MAN] for
Auto range measurement.
(2) Compare function
Compare function:
1) Enable or disable the Compare function by pressing [COMP]
button.
2) Make HI, GO, LO judgment shown on the panel indicator according
to the setting of the upper and low normal value percentage.
3) When the Compare function is relieved, the setting for % and REL
will be relieved too.
Example:
Normal value: 100.00
up limit: 10.0% = up limit value: 110.00
down limit: 20.0% = down limit value: 80.00
The indicators of GO, HI, and LO will be lighted up according to
the resistance value of DUT:
109.00 GO indicator lights up
120.00 HI indicator lights up
70.00 LO indicator lights up
Normal value setting:

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1) Under Compare function, press [NORMAL] button to turn on/off
the function of normal value setting.
2) When the normal value setting is enabled, the maximum number
displayed on the normal value area will be flashing, adjust the value
by using [▲]and [▼], and move the flashing number by using [ ] or
[ ], then press [ENTER] to confirm the correct value. The maximum
normal value is set at 33000 while the minimum normal value is set at
00000.
3) After setting, the HI, LO, GO judgment is according to the new
setting value.
4) If the setting is not saved, once jump out the setting function and re-
power on, the setting will be cleared.
High limit percentage setting:
1) Under the compare function, press [HIGH] to turn on/off the up
limit percentage setting function, and press [SHIFT] to clear the
setting.
2) After setting, the maximum number displayed on the up limit
percentage area will be flashing, adjust the value by using [▲]and
[▼], and move the flashing number by using [ ] or [ ], then press
[ENTER] to confirm the correct value. The maximum up limit percentage
value is set at 999 while the minimum up limit percentage value is set at
000.
3) After setting, the HI, LO, GO judgment is according to the new
setting value.
4) If the setting is not saved, once leave the setting function and re-
power on, the setting will be cleared.
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Low limit percentage setting:
1) Under the compare function, press [LOW] to turn on/off the down
limit percentage setting function, and press [SHIFT] to clear the
setting.
2) After setting, the maximum number displayed on the up/down limit
percentage area will be flashing, adjust the value by using [▲]and
[▼], and move the flashing number by using [ ] or [ ], then press
[ENTER] to confirm the correct value. The maximum down limit
percentage value is set at 999 while the minimum down limit percentage
value is set at 000.
3) After setting, the HI, LO, GO judgment is according to the new
setting value.
4) If the setting is not saved, once leave the setting function and re-
power on, the setting will be cleared.
The save function for the compare setting:
1) Under Compare function, set the high and low limit percentage of
normal value according to the setting procedure of Normal value,
High limit percentage and low limit percentage.
2) Press [SHIFT] and [RECALL] in sequence getting into save and
recall function of Compare setting.
3) Switch to save function by pressing [▲] or [▼], and the “SAVE”
message will be displayed on the panel, press [ENTER] to confirm the
setting, or press [SHIFT] to clear the setting.
4) Among the message “S MXX” displayed on the panel, XX means the
number of the storage group from 00 to 19. Use [▲] or [▼], [ ] or
[ ] to adjust the save location, then press [ENTER] to replace the
previous save location, or press [SHIFT] to clear the setting.