User Manual

14 GMC-I Messtechnik GmbH
9.3 Milliohm Measurement with 200 mA or 20 mA DC [m]
Ð Make sure that the device under test is voltage-free (see
chapter 7.1). Interference voltages distort measurement
results!
Ð Set the rotary selector switch to “m”.
Ð Connect the device under test as shown.
KC4 Kelvin clips and KC27 Kelvin probes (available as
accessories) allow for easy, correct connection.
Resistance at the current jacks should amount to <1.
Ð If applicable, select the desired measuring range using
the MAN|AUTO key: 30 m, 300 m, 3  or 30 .
This measuring method is suitable for resistances with
inductances of up to 1 H.
Thermovoltage Correction in the 30/300 m Range
Ð Press the FUNC key in order to measure thermovoltage.
Wait until the measured value has settled in. This may
take several seconds, depending upon inductivity. Then
press the FUNC key once again in order to return to the
milliohm measuring function. All future measurement
result will be corrected based upon the previously
measured thermovoltage value. ZERO appears at the
display in order to indicate active compensation.
Measurements at Inductive Devices
Coils in motors, choke ballasts and contactors are highly
inductive. Changes in current at inductive devices, including
switching the milliohmmeter on and off or changing the
measuring range, result in a corresponding voltage change.
These changes may be of significant magnitude, and may
result in arcing under unfavorable conditions. The
milliohmmeter is protected against arcing by means of
suitable voltage arrestors.
9.4 Milliohm Measurement with 1 A Pulsating Measuring
Current [m@1 A]
(automatic thermovoltage correction in 3  300 m  range)
Ð Make sure that the device under test is voltage-free (see
chapter 7.1). Interference voltages distort measurement
results!
Ð Set the rotary selector switch to “m@1A”.
Ð Connect the device under test as shown.
KC4 Kelvin clips and KC27 Kelvin probes (available as
accessories) allow for easy, correct connection.
Resistance at the current jacks should amount to <0.2.
Ð If applicable, select the desired measuring range using
the MAN|AUTO key: 3m, (30 m or 300 m
Thermovoltage is compensated automatically.
Note!
Due to high current consumption during this
measurement, NiMH storage batteries should be
installed and the NA HIT 2x mains power battery
charger should be used.
10 Temperature Measurement [C]
Resistance thermometers (available as accessories) are used
for temperature measurement. A 2-pole measurement is
utilized. Cable resistance is set to 0.1  as a default value.
Selecting Temperature Unit of Measure and Sensor Type
Ð Set the rotary selector switch to “C”. Press FUNC to
access the selection menu for temperature unit of
measure and sensor type. sensr and selCt are displayed.
Ð Press the FUNC key to select the desired temperature unit
of measure: C or F.
Ð Select the sensor type (RTD) with the keys.
Ð Connect the sensor to the two jacks (see diagram).
Note!
The selected temperature unit of measure and sensor
type remain unchanged after exiting the function, and
when the instrument is switched off.
0023.2
C
sensr
pt1000 selCt
C

Pt100
FUNC
FUNC
00.10
temp



Cable
Resistance

Pt1000 (TF220)
Ni100
Ni1000
0  50


+
pt1000

FUNC
RTD
C / F
rlead