GW Instek GOM-804 User manual

D.C. Milli-Ohm Meter
GOM-804 & GOM-805
USER MANUAL
GW INSTEK PART NO. 82OM-80500EA1
ISO-9001 CERTIFIED MANUFACTURER

This manual contains proprietary information, which is protected by
copyright. All rights are reserved. No part of this manual may be
photocopied, reproduced or translated to another language without
prior written consent of the Good Will company.
The information in this manual was correct at the time of printing.
However, Good Will continues to improve products and reserves
the right to change specifications, equipment, and maintenance
procedures at any time without notice.
Good Will Instrument Co., Ltd.
No. 7-1, Jhongsing Rd., Tucheng Dist., New Taipei City 236, Taiwan.

Table of Contents
3
Table of Contents
SAFETY INSTRUCTIONS ....................................................5
Safety Symbols ....................................................5
Safety Guidelines ................................................6
GETTING STARTED ............................................................9
GOM-804/805 Characteristics........................... 10
Key Features ...................................................... 13
Model Lineup .................................................... 14
Front Panel Overview ........................................ 15
TFT-LCD Overview ............................................ 19
Rear Panel Overview ......................................... 21
Set Up ............................................................... 23
MEASUREMENT...............................................................27
Resistance Measurement .................................. 29
Compare Function............................................. 41
Binning Function............................................... 46
Temperature Measurement ............................... 50
Temperature Compensation .............................. 52
Temperature Conversion ................................... 56
Measurement Settings ...................................... 60
System Settings ................................................ 69
HANDLER/SCAN INTERFACE ..........................................77
Handler Overview ............................................. 78
Pin Definitions for the Handler Interface .......... 80
Scan Overview................................................... 82
Configure Interface ........................................... 90
SAVE/RECALL...................................................................99
COMMAND OVERVIEW .................................................102
Command Syntax ............................................ 102
Command List................................................. 105

GOM-804 & GOM-805 User Manual
4
General Commands......................................... 108
Compare Commands....................................... 112
Binning Commands......................................... 117
Temperature Compensate Commands ............ 122
Temperature Conversion Commands .............. 123
Temperature Commands ................................. 125
Scan Commands ............................................. 126
Source Commands .......................................... 131
Meas. Setup Commands ................................. 132
System Commands.......................................... 137
Memory Commands ........................................ 141
Status Commands ........................................... 143
IEEE 488.2 Common Commands..................... 144
Status system .................................................. 147
FAQ ................................................................................148
APPENDIX ......................................................................149
Function Selection Combinations ................... 150
Temperature Measurement ............................. 151
Specifications .................................................. 154
Dimensions ..................................................... 158
Declaration of Conformity ............................... 159
INDEX ............................................................................160

SAFETY INSTRUCTIONS
5
SAFETY INSTRUCTIONS
This chapter contains important safety instructions that you must follow
when operating the GOM-804/805 or when keeping it in storage. Read the
following before any operation to insure your safety and to keep the
GOM-804/805 in the best possible condition.
Safety Symbols
These safety symbols may appear in this manual or on the GOM-804/805.
WARNING
Warning: Identifies conditions or practices that could
result in injury or loss of life.
CAUTION
Caution: Identifies conditions or practices that could
result in damage to the instrument or to other properties.
DANGER High Voltage
Attention Refer to the Manual
Protective Conductor Terminal
Earth (ground) Terminal
Do not dispose electronic equipment as unsorted
municipal waste. Please use a separate collection facility
or contact the supplier from which this instrument was
purchased.

GOM-804 & GOM-805 User Manual
6
Safety Guidelines
General Guideline
CAUTION
Do not place any heavy objects on the instrument.
Avoid severe impact or rough handling that leads to
damaging the instrument.
Do not discharge static electricity to the instrument.
Use only mating connectors, not bare wires, for the
terminals.
Do not disassemble the instrument unless you are
qualified as service personnel.
(Note) EN 61010-1:2010 specifies the measurement categories and
their requirements as follows. The GOM-804/805 doesn’t fall
under category II, III or IV.
Measurement category IV is for measurements performed at the
source of low-voltage installation.
Measurement category III is for measurements performed in the
building installation.
Measurement category II is for measurements performed on the
circuits directly connected to the low voltage installation.
Power Supply
WARNING
AC Input voltage: 100 - 240 V AC, 50 - 60Hz, 25VA
The power supply voltage should not fluctuate more
than 10%.
Connect the protective grounding conductor of the AC
power cord to an earth ground, to avoid electrical
shock.
Cleaning the
GOM-804/805
Disconnect the power cord before cleaning.
Use a soft cloth dampened in a solution of mild
detergent and water. Do not spray any liquid into the
instrument.
Do not use chemicals or cleaners containing harsh
material such as benzene, toluene, xylene, and acetone.
Operation
Environment
Location: Indoor, no direct sunlight, dust free, almost
non-conductive pollution (Note below)
Temperature Range: 0~35°C, Relative Humidity:
<80%RH; >35°C, Relative Humidity: <70%RH
Altitude: < 2000m
Operating Environment: 0°C to 40°C (operation)
Pollution Degree 2

SAFETY INSTRUCTIONS
7
(Note) EN 61010-1:2010 specifies the pollution degrees and their
requirements as follows. The GOM-804/805 falls under degree 2.
Pollution refers to “addition of foreign matter, solid, liquid, or
gaseous (ionized gases), that may produce a reduction of dielectric
strength or surface resistivity”.
Pollution degree 1: No pollution or only dry, non-conductive pollution
occurs. The pollution has no influence.
Pollution degree 2: Normally only non-conductive pollution occurs.
Occasionally, however, a temporary conductivity caused by
condensation must be expected.
Pollution degree 3: Conductive pollution occurs, or dry,
non-conductive pollution occurs which becomes conductive due to
condensation which is expected. In such conditions, equipment is
normally protected against exposure to direct sunlight, precipitation,
and full wind pressure, but neither temperature nor humidity is
controlled.
Storage
Environment
Location: Indoor
Storage Conditions: −10°C to 70°C
Temperature Range: 0~35°C, Relative Humidity:
<90%RH; >35°C, Relative Humidity: < 80%RH
Disposal
Do not dispose this instrument as unsorted municipal
waste. Please use a separate collection facility or contact
the supplier from which this instrument was purchased.
Please make sure discarded electrical waste is properly
recycled to reduce environmental impact.

GOM-804 & GOM-805 User Manual
8
Power cord for the United Kingdom
When using the instrument in the United Kingdom, make sure the power
cord meets the following safety instructions.
NOTE: This lead / appliance must only be wired by competent persons
WARNING: THIS APPLIANCE MUST BE EARTHED
IMPORTANT: The wires in this lead are coloured in accordance with the
following code:
Green/ Yellow:
Earth
Blue:
Neutral
Brown:
Live (Phase)
As the colours of the wires in main leads may not correspond with the
coloured marking identified in your plug/appliance, proceed as follows:
The wire which is coloured Green & Yellow must be connected to the Earth
terminal marked with either the letter E, the earth symbol or coloured
Green/Green & Yellow.
The wire which is coloured Blue must be connected to the terminal which is
marked with the letter N or coloured Blue or Black.
The wire which is coloured Brown must be connected to the terminal marked
with the letter L or P or coloured Brown or Red.
If in doubt, consult the instructions provided with the equipment or contact
the supplier.
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, a 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 exposed wiring from a cable, plug or connection that is engaged in a live
socket is extremely hazardous. If a cable or plug is deemed hazardous, turn
off the mains power and remove the cable, any fuses and fuse assemblies. All
hazardous wiring must be immediately destroyed and replaced in accordance
to the above standard.

GETTING STARTED
9
GETTING STARTED
This chapter describes the GOM-804/805 in a nutshell, including its main
features as well as its front and rear panels. After going through the panel
overview, follow the Power-up sequence before attempting to use the
instrument.
Please note the information in this manual was correct at the time of printing.
However as GW Instek continues to improve its products, changes can occur
at any time without notice. Please see the GW Instek website for the latest
information and content.
Characteristics
GOM-804/805 Characteristics ................................10
Key Features ...........................................................13
Model Lineup .........................................................14
Panel Overview
Front Panel Overview .............................................15
TFT-LCD Overview..................................................19
Rear Panel Overview...............................................21
Setup
Tilt Stand................................................................23
Power Up................................................................24
4 Wire Kelvin Connection .......................................25
Zeroing (Relative Function)....................................26

GOM-804 & GOM-805 User Manual
10
GOM-804/805 Characteristics
GOM-804 and GOM-805 are modern high precision programmable DC
Milli-ohm meters suitable for low resistance measurements of switches, relays,
connectors, PCB tracks and a variety of other devices. The meters feature a
color TFT-LCD screen with easy-to-read measurement results. With the
easy-to-use features, superior performance and automatic test interfaces, these
meters are dependable instruments for resistance measurements.
Easy to Use
Features
Each test function on the GOM-804/805 can be easily
activated by pressing a single front panel key. All the
settings and measurement results are displayed and set on
the TFT-LCD panel at the same time making each
function naturally intuitive to use.
Each primary and secondary measurement result is
displayed prominently on the display along with any
corresponding settings. For sequential measurement
results, such as those from the scan or binning function,
are tabulated in an intuitive and easy-to-read format.
In addition, the meters can recall previously used settings
upon startup, allowing the meter to be ready the next
time it used in a matter of moments. The meters can also
save or recall up to 20 sets of function settings.
Performance
The GOM-804/805 has nine selectable measurement
ranges from 50mΩ to 5MΩ, a constant current source of
1uA to 1A, an accuracy of up to 0.05%, a 1uΩ resolution
and performs measurements using four wire Kelvin
connections for accurate, consistent measurements.
The ability to choose between high accuracy
measurements at 10 samples/sec (full scale at 50000
counts) or high speed measurements at 60 samples/sec
(full scale at 50000 counts), allows the GOM-804/805 the
flexibility to fulfill a number of different measurement
roles.