active differential probe

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Steve Michener
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Joined: Wed Oct 31, 2018 5:56 pm

active differential probe

Post by Steve Michener » Sun Aug 11, 2019 4:39 am

PICO sells two active diff probes, one has a 700v max and the other 1400v max. What would be the advantage of purchasing the 700v probe? Or what disadvantages should I be aware of when using the 1400v probe instead of the 700v probe?

Steve Smith
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Joined: Sun Aug 25, 2013 7:22 am

Re: active differential probe

Post by Steve Smith » Mon Aug 12, 2019 11:42 am

Hello and thank you for the post.

Initially the purchase of the differential probe should be governed by the expected peak voltages you are likely to measure.

Past experience with Hybrid vehicles would have found the TA041 (700 V Max Diff Probe) to be sufficient, however this is creeping over 1000 V in some applications and so the TA057 (1400 V Max Diff Probe) will cover you for every occasion thanks to increased attenuation.

Whilst the increased attenuation of the TA051 (x200) allows for higher voltage measurements it does impact upon noise reduction.

In a nutshell, the TA041 with x100 attenuation has improved noise reduction properties (relative to the measured signal) than the TA051 with x200 attenuation.

For example, if we are chasing a voltage signal (below 700 V peak) which may be consumed with noise, the TA041 will reject more noise given is has twice the Common Mode Rejection Ratio to the TA051.

On the flip side, if our voltage signal is expected to peak above 700 V then we don’t have a choice, we must use the TA051.

By no means does this reflect upon the performance of the TA051, it is more the characteristics of attenuation and differential probe activity (Signal to noise ratio)

My colleague has summed this up nicely here:
“The TA041 will allow you to capture signals half the size of the smallest signal that TA057 can capture, while the TA057 will allow you to capture signals twice the size of the largest signal that the TA041 can capture.”

I hope this helps and please feedback should you require any clarification, take care……Steve

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