GW Instek GDM-8261A User manual

Dual Measurement Multimeter
GDM-8261A
USER MANUAL
GW INSTEK PART NO. 82DM-8261AEC1
ISO-9001 CERTIFIED MANUFACTURER

This manual contains proprietary information, which is protected by
copyrights. All rights are reserved. No part of this manual may be
photocopied, reproduced or translated to another language without
prior written consent of 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 (R.O.C.).

Table of Contents
3
Table of Contents
SAFETY INSTRUCTIONS ....................................................6
Safety Symbols ....................................................6
Safety Guidelines ................................................7
GETTING STARTED ..........................................................10
GDM-8261A Characteristics .............................. 11
Front Panel Overview ........................................ 12
Rear Panel Overview ......................................... 18
Set Up ............................................................... 20
BASIC MEASUREMENT ....................................................23
Basic Measurement Overview ........................... 25
AC/DC Voltage Measurement ........................... 27
AC/DC Current Measurement ........................... 32
2W/4W Resistance Measurement ..................... 34
Diode Test ......................................................... 37
Continuity Test .................................................. 38
Frequency/Period Measurement ....................... 41
Temperature Measurement ............................... 43
DUAL MEASUREMENT ....................................................49
Dual Measurement ........................................... 49
ADVANCED MEASUREMENT ...........................................55
Advanced Measurement Overview .................... 56
dBm/dB/W Measurement ................................. 58
Max/Min Measurement..................................... 61
Relative Value Measurement ............................. 62
Hold Measurement ........................................... 64
Compare Measurement..................................... 65
Math Measurement........................................... 68
SYSTEM/DISPLAY CONFIGURATION ..............................74
Refresh Rate Setting.......................................... 75

GDM-8261A User Manual
4
View Serial Number...........................................75
Trigger Setting ...................................................76
Filter Setting .....................................................79
Display Setting ..................................................83
Measurement Configuration Settings ...............84
ADC Setting.......................................................88
Frequency / Period Settings ..............................93
Identification Settings .......................................96
STORE/RECALL ............................................................... 97
Store Measurement Record ...............................98
Recall Measurement Record..............................99
Save Instrument Settings ................................ 100
Recall Instrument Settings .............................. 101
SCANNER (OPTIONAL) .................................................103
GDM-SC1 Scanner Specifications ................... 104
Scanner Installation ........................................ 104
Setup Scan ...................................................... 113
Run Scan ......................................................... 120
DIGITAL I/O ...................................................................123
Digital I/O Terminal Configuration ................. 124
REMOTE CONTROL .......................................................130
Configure Interface.......................................... 132
Web Control Interface ..................................... 159
Command Syntax ............................................ 163
Command Set.................................................. 164
FAQ ................................................................................209
APPENDIX ......................................................................211
Firmware Version ............................................ 212
Fuse Replacement ........................................... 213
Menu Tree ....................................................... 215
Specifications .................................................. 217
EC Declaration of Conformity.......................... 227

Table of Contents
5
INDEX ............................................................................228

GDM-8261A User Manual
6
SAFETY INSTRUCTIONS
This chapter contains important safety instructions that
you must follow when operating the GDM-8261A and
when keeping it in storage. Read the following before any
operation to insure your safety and to keep the
GDM-8261A in the best possible condition.
Safety Symbols
These safety symbols may appear in this manual or on the GDM-8261A.
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 GDM-8261A or to other
property.
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.

SAFETY INSTRUCTIONS
7
Safety Guidelines
General Guideline
CAUTION
Make sure that the voltage input level does not exceed
DC1000V/AC750V.
Make sure the current input level does not exceed 10A.
Do not place any heavy object on the GDM-8261A.
Avoid severe impact or rough handling that can lead to
damaging the GDM-8261A.
Do not discharge static electricity to the GDM-8261A.
Use only mating connectors, not bare wires, for the
terminals.
Do not block or obstruct the cooling fan vent opening.
Do not perform measurement at the source of a
low-voltage installation or at building installations
(Note below).
Do not disassemble the GDM-8261A unless you are
qualified as service personnel.
Make sure that the Sense LO terminal to COM port is
limited to 100Vpk, the Sense HI to Sense LO terminals
are limited to 200Vpk and the COM port to earth is
limited to 500Vpk.
(Note) EN 61010-1:2010 specifies the measurement categories and
their requirements as follows. The GDM-8261A falls under
category II 600V.
Measurement category IV is for measurement performed at the source
of low-voltage installation.
Measurement category III is for measurement performed in the
building installation.
Measurement category II is for measurement performed on the circuits
directly connected to the low voltage installation.
Power Supply
WARNING
AC Input voltage: 100/120/220/240 V AC ±10%,
45Hz to 66Hz / 360Hz to 440Hz
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.

GDM-8261A User Manual
8
Fuse
WARNING
Fuse type: 0.315AT 100/120VAC
0.125AT 220/240 VAC
Make sure the correct type of fuse is installed before
power up.
To avoid risk of fire, replace the fuse only with the
specified type and rating.
Disconnect the power cord before fuse replacement.
Make sure the cause of a fuse blowout is fixed before
fuse replacement.
Cleaning the
GDM-8261A
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
GDM-8261A.
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: Full accuracy for 0°C to 55°C.
Humidity: Full accuracy to 80% RH at 40°C
(Note) EN 61010-1:2010 specifies the pollution degrees and their
requirements as follows. The GDM-8261A 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
Temperature: −40°C to 70°C
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.

SAFETY INSTRUCTIONS
9
Power cord for the United Kingdom
When using the GDM-8261A 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.

GDM-8261A User Manual
10
GETTING STARTED
This chapter describes the GDM-8261A in a nutshell,
including an Overview of its main features and front /
rear panel introduction. After going through the
Overview, follow the Power-up sequence to properly
setup the GDM-8261A.
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
GDM-8261A Characteristics................................... 11
Panel Overview
Front Panel Overview ............................................. 12
Measurement Keys (upper row) ............................. 13
Measurement Keys (lower row) ............................. 16
Rear Panel Overview .............................................. 18
Setup
Tilt Stand ............................................................... 20
Power Up ............................................................... 21

GETTING STARTED
11
GDM-8261A Characteristics
The GDM-8261A is a portable, dual-display digital
multimeter suitable for a wide range of applications, such
as production testing, research, and field verification.
Performance
High DCV accuracy: 0.0035%
High current range: 10A
High Voltage range: 1000V
High ACV frequency response: 300kHz
Features
6
2
1
digits
Multi functions: ACV, DCV, ACI, DCI, 2W/4W R, Hz,
Temp, Continuity, Diode test, MAX/MIN, REL, dBm,
Hold, MX+B, 1/X, REF%, dB, Compare, Statistics.
Manual or Auto ranging
AC true RMS
Interface
Voltage/Resistance/Diode/Temperature input
Current input
4W sense input
USB device/RS232/GPIB(optional)/LAN(optional)
for remote control
9-pin digital I/O
16 channel scanner (optional)
Optional Items
16 channel scanner
GPIB port
Ethernet port

GDM-8261A User Manual
12
Front Panel Overview
TEMP
/Hz/P2/4WACV DCV ACI DCI
HOLD MX/MNRELTRIGAUTO 2ND
SENSORdBMATHSTORE dBmSTEPSCAN RECALL
MENUREL# FILTERINT/EXTCOMPRATE
ENTER LOCAL
POWER
RANGE CHOICES
/ EXITSHIFT
GDM-8261A Digit Dual Measurement Multimeter
612
W4W
SENSE
INPUT
VW
HI
LO
MAX
200Vpk
MAX
DC1000V
AC 750V
100Vpk
MAX
500Vpk
MAX COM
FUSE
T1.25A
250V
CAT 600V
10A 1.2A
DC/AC 10A
Terminal
Measurement
Keys
Input HI
Terminal
Sense LO Terminal
Power Switch
Main
Display
DC/AC 1A
Terminal,
AMPS Fuse
Holder
Input LO
Terminal
(COM port)
Sense HI
Terminal
Power Switch
POWER
Turns On or Off the main
power. For the power up sequence, see
page 21.
Main Display
Shows measurement results and parameters.
For display configuration details, see page 82 (light
setting).
DC/AC 1A
Terminal
AMPS Fuse
Holder
1.2A
FUSE
T1.25A
250V
As a fuse, protects the instrument from
over-current. Rating: T1.25A, 250V.(This
terminal accepts DC/AC current input)
For the fuse replacement procedure, see
page 214.
DC: 100μA~1A
AC:1mA~1A
For details see page 32.
Sense LO
Terminal
LO
Accepts LO sense line in 4W resistance
measurement. For details, see page 34

GETTING STARTED
13
Sense HI
Terminal
W4W
SENSE
HI
Accepts HI sense line in 4W resistance
measurement. For details, see page 34.
Input LO
Terminal
COM
Accepts ground (COM) line in all
measurements except the sense line in
4W Resistance (page 34).
The maximum withstand voltage
between this terminal and earth is
500Vpk.
Input HI Terminal
INPUT
VW
Used as an input port for all
measurements except for DC/AC
Current measurements.
DC/AC 10A
Terminal
10A
Accepts DC/AC Current input.
For DCI or ACI details, see page 32.
Measurement Keys (upper row)
SHIFT/EXIT
/ EXITSHIFT
The Shift key is used to select the
secondary functions assigned to
each front panel key. When pressed,
the SHIFT indicator appears in the
display.
As the Exit key, it gets out of the
parameter configuration mode and
goes back to the measurement result
display mode.
ACV
ACV
Measures AC Voltage (page 27).
SHIFT →ACV
(SCAN)
/ EXITSHIFT
ACV
SCAN
Starts the optional scan
measurement (page 113).
DCV
DCV
Measures DC Voltage (page 27).

GDM-8261A User Manual
14
SHIFT →DCV
(STEP)
/ EXITSHIFT
DCV
STEP
Starts the step measurement (page
113) using the optional scanner.
ACI
ACI
Measures AC Current (page 32).
SHIFT →ACI
(RECALL)
/ EXITSHIFT
ACI
RECALL
Recalls a normal measurement
result, standard deviation
measurement readings (page 99) or
scan measurement results (page
121).
DCI
DCI
Measures DC Current (page 32).
SHIFT →DCI
(STORE)
/ EXITSHIFT
DCI
STORE
Stores a measurement result (page
98).
2/4W
(Resistance)
2/4W
Measures 2-wire or 4-wire
Resistance (page 33).
SHIFT →2/4W
(MATH)
/ EXITSHIFT
2/4W
MATH
Enters the Math measurement mode
(page 68).
/
(Diode/
Continuity)
/
Tests Diode (page 37) or Continuity
(page 38).
SHIFT →
/
(dBm)
/ EXITSHIFT
/
dBm
Measures dBm (page 58).
Hz/P (Frequency/
Period)
Hz/P
Measures Frequency or Period (page
41).

GETTING STARTED
15
SHIFT + Hz/P
(dB)
/ EXITSHIFT
Hz/P
dB
Measures dB (page 59).
TEMP
(Temperature)
TEMP
Measures Temperature (page 43).
SHIFT + TEMP
(SENSOR)
/ EXITSHIFT
TEMP
SENSOR
Selects the type of thermocouple
used in the Temperature
measurement (page 44).

GDM-8261A User Manual
16
Measurement Keys (lower row)
AUTO/ENTER
AUTO
ENTER
As the AUTO key, selects the
measurement range automatically.
As the Enter key, confirms the
entered value.
SHIFT →AUTO
(RATE)
/ EXITSHIFT
AUTO
RATE
ENTER
Selects the measurement update
rate: Slow, Medium, or Fast (page
25).
Up/Down
RANGE
Selects the parameter in various
occasions: higher ( ) or lower
().
HOLD
HOLD
Activates the Hold function (page
64).
SHIFT →HOLD
(COMPare)
/ EXITSHIFT
HOLD
COMP
Activates the Compare
measurement (page 65).
TRIG (Trigger)
TRIG
Triggers sample acquisition
manually (page 76).
SHIFT →TRIG
(Int/Ext Trigger)
/ EXITSHIFT
TRIG
INT/EXT
Selects the Internal or the External
trigger source (page 76).
Left/Right
HOLD TRIG
CHOICES
Selects parameters in various menus:
left ( ) or right ( ).
REL
REL
Measures the Relative value (page
62).

GETTING STARTED
17
SHIFT →REL
(RELative base)
/ EXITSHIFT
REL
REL#
Manually sets the reference value for
the Relative value measurement
(page 62).
MX/MN
(MAX/ MIN)
MX/MN
Measures the Maximum or the
Minimum value (page 61).
SHIFT →MX/MN
(FILTER)
/ EXITSHIFT
MX/MN
FILTER
Selects the digital filter type for the
signal sampling (page 79).
2nd (Display) /
LOCAL
2ND
LOCAL
As the 2nd key, selects the
measurement item on the 2nd
display (page 49). Pressing and
holding for more than 1 second
turns off the 2nd display.
As the Local key, releases the remote
control and returns the instrument
to local panel operation (page 132).
SHIFT → 2nd
(Menu)
/ EXITSHIFT
2ND
MENU
LOCAL
Enters the configuration mode for;
System Settings, Measurement
Settings, ADC Settings,
Frequency/Period Settings, I/O
Settings, TX TERM Settings and
Scanner Settings.

GDM-8261A User Manual
18
Rear Panel Overview
RS232
CAL KEY
DIGITAL I / O
SER.NO. LABEL
50 , 60 , 400Hz
25VA MAX.
LINE RATING
FUSE LINE
100VAC
120VAC
220VAC
240VAC
0.315AT
0.125AT
TEST LEADS BEFORE REPLACING FUSE
DISCONNECT POWER CORD AND
16 CHANNEL
SCANNER
MAX. RATING
250V , 2A
RS-232C
Port
Optional
Scanner Port Power Cord Socket
Fuse
0.315AT/
0.125AT
CAL Key
Port
Optional
Communication port USB Device
Port
Digital I/O
Port
Power Cord
Socket
100
220
120
240
Accepts the power cord. AC
100/120/220/240V ±10%,
45Hz~66Hz, 360Hz~440Hz.
For power on sequence, see page 21.
Fuse Socket
100
220
120
240
Holds the main fuse:
100/120 VAC: 0.315AT
220/240 VAC: 0.125AT
For fuse replacement details, see page
213.
RS-232C port
RS232
Accepts an RS-232C cable for remote
control; DB-9 male connector.
For remote control details, see page
133.

GETTING STARTED
19
USB device port
Accepts a USB device cable for remote
control; Type A, female connector.
For remote control details, see page
132.
CAL key port
CAL KEY
Reserved for internal purposes such as
firmware updates and calibration.
Digital I/O port
DIGITAL I / O
Accepts a digital I/O cable for the
Hi/Lo limit tests; DB-9 pin, female
connector.
For digital I/O details, see page 124.
Optional slot x1
Accepts the optional 16 channel scanner module. For
scanner details, see page 103.
16 CHANNEL
SCANNER
MAX. RATING
250V , 2A
Optional
Communication
port
Accepts an optional GPIB or Ethernet
card.

GDM-8261A User Manual
20
Set Up
Tilt Stand
Tilt stand steps
Pull out the
handle sideways
and rotate it.
Place the unit
horizontally,
Or in the tilt
stand position.
Place the handle
vertically for hand
carry.