Gossen Metrawatt Metrahit Iso Insulation measuring device, CAT III 600 V Metrahit Iso Benutzerhandbuch

GMC-I Gossen-Metrawatt GmbH

39

Measurements: V/Hz, 

Ω,  , Temp (°C/°F), 

, M

Ω

@UISO

, A/Hz

5.7

Insulation Resistance Measurement – M

Ω

@UISO

 Function

5.7.1 Preparing for Measurement

Note



Testing the Measurement Cables 
The test probes at the ends of the measurement cables 
should be short circuited before performing insulation 
resistance measurements with the selector switch in the 

Ω 

or the 

 position, in order to make sure that a value close 

to 0 

Ω is displayed at the instrument. Incorrect connection or 

a broken measurement cable can be detected in this way.

Note



Insulation resistance may only be measured at voltage-free 
devices. The measurement cables may not come into con-
tact with one another during high-resistance insulation 
measurements.

➭ Set the rotary switch to “

M

Ω

@UISO

”.

➭ Connect the measurement cables to the two accessible jacks.
➭ Interference voltage measurement (V AC+DC TRMS) is 

conducted in this switch position.

The FUNC | ENTER key for U

ISO

 ON / OFF may only be pressed 

in order to start the insulation resistance measurement if the 
device under test is voltage-free. 

Note



The M

Ω

@UISO

 switch position may only be used for 

insulation resistance measurement. However, if interference 
voltage is inadvertently applied with the switch in this 
position, it appears at the display.
If an interference voltage of 

> 50 V is present, insulation 

resistance measurement is disabled. The LCD continues to 
display the interference voltage value. If a voltage of greater 
than 1000 V is present, an acoustic signal is generated as 
well.

COM mA A

V

Temp

Ω MΩ

ISO

00.00

Ω

Short circuit the measurement cables.

R

x

Ω

M

Ω

@UISO

V

Interference Voltage Detection

000.0

V

DC

AC

TRMS

1M

Ω