Megohm meters

Megohm meters are designed to test appliances and installations with a high(er) test voltage, for instance engines, cables, transformers etc. The general functions of these instruments are concentrated to the characteristics of the insulation material. These characteristics are heavily influenced in case the material is under severe circumstances for a long(er) period of time.

 

They show the direct relation between the insulation material and the test voltage or even between the insulation material and the test period as well as the recovery after de-charges. The quality of the insulation, based on the value of the insulation resistance, can lead to the decision to repair, maintain or even replace the tested equipment.

 

The megohm meters are also used to test components of over current protecting devices. Each regulation allows that DC Voltage can be used as an alternative for testing the insulation breakdown. In order to do this correctly, a test voltage needs to be connected to the insulation for a certain period of time. In case there is no breach or sign of breaking insulation, the test is positive.

 

An example for such case is the EN/IEC 61010-1: DC test voltage for CAT II/300V is 1880V (basic insulation) or 3060V (double insulation).

 

For testing transmission and/or distribution lines and ‘middle voltage’ distribution systems a 10kV, 15kV and even 20 kV tester is available within the portfolio. This suitcase shaped sturdy instrument is especially engineered for heavy field measurements. These testers can also be used for the detection cable defects.