Hi-

I need a device inline with a 4-20ma sensor that can sense a fast current change within the whole 4-20ma range and switch on a relay for an alarm. This is not to be confused with your average change of rate in the current.

Thanks.

 

A simple differentiator and a voltage comparator would do this, as would a voltage comparator across an inductor in series with the loop.

Regards

cww

 

Thanks. Exactly what I figured. There is no well known product out there for this kind of application ready to buy. This happens to be a new OSHA requirement and would need to be a certified product which I forgot to mention.