In response to ever growing demands for safer and more accurate methods of testing circuit breakers, Weis has developed the self powered MM100 portable micro-ohm meter. It is used for measurement of resistance (μΩ) by injecting a heavy current through a breaker contact or load carrying joint.

A regulated 100A continuous or pulsed current output is used for regular resistance measurement. Alternatively a high current pulsed output (1200A maximum at 4V) allows for testing of the latest arcing and main contacts that require more than 500-600A to determine the difference between them, as well as to see if they are able to carry such a current.

An alternative self powered MM200 micro-ohm meter with fixed output ranges of 10A, 100A or 200A is also available.

As a stand-alone unit, static testing can be performed with a direct readout on a built in LCD meter. When used in conjunction with the Weis SA100, SA100R or SA100RS switchgear analyser / breaker tester (having a travel input for breaker mechanism movement), a dynamic micro-ohm test can be made that will give detailed information about the state of fixed contact surfaces, moving contact surfaces, main contact, arcing contact and the complete current circuit of the breaker in every step during a close-open operation.

Range: 0 to 1.999 or 19.99mΩ (selectable).

With SA100/SA100‘R’ 1200mΩ max.

Resolution: 1 or 10μΩ (range selected).

Accuracy: 1% of reading +/- 1 digit.

Voltage Sense: 1 x voltage input from contact / joint.

Connectors: 4mm safety socket.

• MM100 Self Powered Micro-Ohm Tester with 100/1200A Output
• MM200 Self powered Micro-ohm meter with fixed output ranges of 10A, 100A or 200A