Looking for short intermittent interferences?

By W Thompson, Fluke Corporation

 

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Published in:

Electricity+Control, May 2013 (pages 4 – 5)

Enquiries: email  - wade.thompson@fluke.com

Contact: The Comtest Group, email - info@comtest.co.za

 

 

Owners of national power grids do their best to supply interference free mains, but they are faced with switching devices that leave their mark on the grid coming to our houses. These short intermittent interferences can also be generated in-house by flipping switches.



Two options can assist:

  • The first offers the possibility to record the trend in signal behaviour, which enables an easier visualisation of deviations overtime. The measured data is electronically stored in the scope’s memory, allowing for paperless recording up to 22 days. Using this feature, unexpected short irregularities can easily be spotted.
  • The second is a continuous sampling mode in which the Scope Meter test tool records points ‘as is’ at a rate of 125 MS/s. With a 30 000 point deep memory it can record continuously in this mode for up to 48 hours enabling to capture glitches as short as 8 ns. The recorder function can be set to trigger on specific trigger functions such as single sweep, continuous trigger or start/ stop on a trigger signal.

 

Take note

  • Digital Multi Meters (DMMs) were not designed to detect and measure short glitches on a power supply line.
  • To measure glitches, you require an instrument that can record and store high frequency transient data.
  • A ScopeMeter combines attributes of a DMM and an oscilloscope in a small, powerful, portable package.