RS PRO RM-804 User manual

Instruction Manual
RM-804 & RM-805
D.C. Milli-Ohm Meter
EN FR DE IT SP

Table of Contents
13/10/2016 Version No. 001 1
Table of Contents
SAFETY INSTRUCTIONS ...............................................................3
GETTING STARTED.......................................................................8
RM-804/805 Characteristics ............................................. 10
Key Features ................................................................... 13
Model Lineup................................................................... 14
Front Panel Overview.......................................................15
Rear Panel Overview ....................................................... 20
TFT-LCD Overview .......................................................... 22
Set Up............................................................................. 24
MEASUREMENT.......................................................................... 29
Resistance Measurement ................................................. 31
Compare Function............................................................45
Binning Function.............................................................. 51
Temperature Measurement ............................................... 57
Temperature Compensation.............................................. 59
Temperature Conversion .................................................. 63
Measurement Settings ..................................................... 68
System Settings...............................................................78
HANDLER/SCAN INTERFACE ...................................................... 89
Handler Overview ............................................................ 90
Scan Overview ................................................................94
Configure Interface ........................................................ 105
SAVE/RECALL............................................................................117
COMMAND OVERVIEW.............................................................. 122

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Command Syntax ...........................................................123
Command List................................................................126
BINNing Commands .......................................................130
Calculate Commands......................................................139
Memory Commands........................................................151
Sense Commands ..........................................................153
Source Commands .........................................................158
Status Commands ..........................................................160
System Commands ........................................................162
Temperature Commands.................................................170
Trigger Commands.........................................................177
Userdefine Commands ...................................................181
IEEE 488.2 Common Commands ....................................184
Status system ................................................................189
FAQ...........................................................................................190
APPENDIX.................................................................................191
Function Selection Combinations ....................................192
Temperature Measurement .............................................193
Specifications.................................................................197
Dimensions....................................................................202
Declaration of Conformity ...............................................203

SAFETY INSTRUCTIONS
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SAFETY INSTRUCTIONS
This chapter contains important safety instructions that you must
follow when operating the RM-804/805 or when keeping it in
storage. Read the following before any operation to insure your
safety and to keep the RM-804/805 in the best possible condition.
Safety Symbols
These safety symbols may appear in this manual or on the RM-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

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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 Guidelines
General
Guidelines
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.
(Measurement categories) EN 61010-1:2010 specifies the measurement
categories and their requirements as follows. The RM-804/805 doesn’t fall under
category II, III or IV.
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.
Measurement category I is for measurements performed on circuits not directly

SAFETY INSTRUCTIONS
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connected to Mains.
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
RM-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 products
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

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(Note) EN 61010-1:2010 specifies the pollution degrees and their requirements as
follows. The RM-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.

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Power cord for the United Kingdom
When using the oscilloscope 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.

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GETTING STARTED
This chapter describes the RM-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 RS PRO continues to improve its
products, changes can occur at any time without notice. Please
see the RS PRO website for the latest information and content.
RM-804/805 Characteristics......................................... 10
Key Features .............................................................. 13
Model Lineup .............................................................. 14
Front Panel Overview .................................................. 15

GETTING STARTED
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Rear Panel Overview ...................................................20
TFT-LCD Overview.......................................................22
Set Up.........................................................................24
Tilt Stand...................................................................................24
Power Up...................................................................................25
4 Wire Kelvin Connection..........................................................26
Zeroing (Relative Function).......................................................27

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RM-804/805 Characteristics
RM-804 and RM-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 RM-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 RM-804/805 has nine selectable measurement ranges from
50mΩ to 5MΩ, a constant current source of 1uA to 1A, an

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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 RM-804/805 the flexibility to fulfill a number of different
measurement roles.
Advanced
Temperature
Measurements
The RM-804/805 has a number of advanced temperature
functions that can be used with the optional temperature probe,
PT-100.
The temperature compensation function can extrapolate what the
resistance of a DUT will be at a desired temperature, if the
temperature coefficient of the DUT and the resistance of the DUT
at ambient temperature are known.
The temperature conversion function can be used to extrapolate
what the temperature rise of a DUT will be at specified resistance
if the initial resistance, initial temperature and the constant for the
DUT are known.
Drive Signals
The RM-805 can select a number of different drive signals to suit
a number of different measurement scenarios, for example the
Pulse setting can be used to cancel the effects of thermoelectric
EMF on the measurement results.
Dry Circuit
Dry circuit testing allows the RM-805 to measure the contact

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Testing
resistance of switches and connectors according to the DIN IEC
512 and ASTM B539 standards. The open circuit voltage will not
exceed 20mV in this mode to prevent the oxidization layer on
metal switches and connector points from breakdown. RM-805
only.
Automatic
Testing
For automatic testing The RM-804/805 has a handler interface
designed for automatic testing. The handler interface outputs the
status of PASS, FAIL, HI, LO, READY and EOT signals and
inputs a trigger control signal. Automatic testing is used with the
binning, compare and scan functions.
For computer control applications, RS-232 and USB are standard
remote interfaces, with GPIB as standard only for the RM-805
and RM-804G.
Applications
Production testing for contact resistance of switches, relays,
connectors, cables and printed circuit boards and other low
resistance devices.
Component testing of resistors, motors, fuses and heating
elements.
Incoming inspection and quality assurance testing.
Conductivity evaluation for product design.

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Key Features
Performance
50,000 counts
Measurement Range: 50mΩ~5MΩ
Accuracy of up to 0.05%
Compare function
Binning function
Manual or Auto-ranging
Continuous or Triggered measurement modes
Temperature measurement, temperature compensation and
temperature conversion
Four-wire Kelvin measurement method
Selectable power-on settings
Diode test
Alarm settings for function-specific PASS/FAIL test results
Sampling rate: 10 or 60 sampling/sec
Standard interfaces: USB/RS232/Scan/Handler/GPIB(RM-805,
RM-804G)
Save/Recall settings: 20 memory sets
External I/O logic function

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Model Lineup
Feature / Model
RM-804
RM-804G*
RM-805
Ohm Measurement
✔
✔
✔
Compare Function
✔
✔
✔
Diode Measurement
✔
✔
✔
Temp. Compensation
✔
✔
✔
Temp. Conversion
✔
✔
✔
Temp Measurement
✔
✔
✔
Dry Circuit
✘
✘
✔
Drive Selection
✘
✘
✔
Binning Function
✘
✘
✔
Interface
GPIB Interface
✘
✔
✔
RS-232 Interface
✔
✔
✔
USB Device Interface
✔
✔
✔
Handler/EXT IO/Scan
Interface
✔
✔
✔
Temperature Sensor
Interface
✔
✔
✔
* The RM-804G is simply the RM-804 with the factory-installed GPIB option.
Please note that the GPIB option cannot be user-installed on the RM-804. The
option must be ordered prior to purchase.

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Front Panel Overview
SOURCE SENSE POWER SENSE SOURCE
Rx
Ohm Compare Binning
TEMP
TCONVTC
Speed REL RT
Trigger
DryScan
Display Diode Drive
ESC
GND
GUARD
Enter
Local Range
ESC key
GND
terminal
Function
key
LCD display
Power key
Arrow keys,
Enter keys
GUARD
terminal
Sense+, Source+Sense-, Source-
Power Switch
SOURCE SENSE POWER SENSE SOURCE
Rx
DC Milliohm Meter
G O M - 8 0 5
Ohm Compare Binning
TEMP
TCONVTC
Speed REL RT
Trigger
DryScan
Display Diode Drive
ESC
GND
GUARD
Enter
Local Range
Turns On or Off the main power.
Measurement Terminals
Source, Sense
Terminals
Rx
SOURCE SENSE SENSE SOURCE
Sense + and Sense - terminals.
Current source terminals: Source + and Source -.

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CAUTION
When measuring components with polarity,
connect Source+ to the positive potential and
connect Source- to the negative potential of
the component.
WARNING
Discharge any DUT before measurement to
avoid damaging the RM-804/805.
GND Terminal
GND
Connect the GND (ground) terminal to the
earth ground.
GUARD Terminal
GUARD
The GUARD terminal has the same potential
as earth, but cannot be substituted for it.
Connect the GUARD terminal to the cable
shield layer of the test leads to help reduce
noise.
Function Keys
Ohm
The Ohm key activates the resistance
measurement function.
Compare
The Compare key activates the comparator
function.
Binning
The Binning key activates the binning
function to grade the DUTs into eight bins
according to the tolerance settings. RM-805
only.

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TC
The TC key activates the TC (temperature
compensation) function which calculates the
resistance of a DUT at a specified
temperature given the resistance of the DUT
at the ambient temperature and the
temperature coefficient of the DUT is known.
TCONV
The TCONV (Temperature Conversion)
function calculates the temperature of a DUT
given an initial temperature, initial resistance,
measured resistance and a constant
(inferred zero resistance temperature) for the
DUT.
TEMP
The TEMP key activates the temperature
measurement function.
Speed
The Speed key toggles between 10 samples
per second and 60 samples per second
(Slow rate and Fast rate).
REL
The REL key is used to perform a zero
adjustment to the test leads or a DUT.
RT
The RT key is used to display the real-time
(not averaged) measured resistance value.
Scan
The Scan key is used to turn on the Scan
function.

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Dry
The Dry key is used to turn on the dry circuit
measurement mode which allows the RM-
805 to measure the contact resistance of
switches and connectors according to DIN
IEC 512 and ASTM B539 standards. RM-805
only.
Trigger
When in the internal trigger mode, pressing
the Trigger key will turn on the external
trigger mode. When in the external trigger
mode, pressing the Trigger key will perform a
manual trigger.
A long press of the Trigger key when in
external trigger mode will reset the trigger
mode back to the internal trigger mode.
Display
The Display key toggles between the
standard display mode and the simplified
display mode (sans menus and display
icons).
Local
The LOCAL key will switch the milliohm
meter between local and remote mode.
Diode
The Diode key is used to turn on the Diode
measurement function.