Low Pressure ER Extractable 3/4 Probe is basically a thin metal probe of different shapes with a well-known electrical resistance.

The material loss due to the corrosive attack causes an increase of resistance measured by the AE-Corr-Ohmeter which is a suitable instrument that gives directly Corrosion Rate, for every time interval (at least in Continuous Mode), without any action on the plant.

ER Probe is composed of a Probe Body of length determined by the process conditions and by a Sensing Element, that could be Wire Loop or Tubular type. 

A threaded or flanged Packing Gland is connected to a Ball Valve.

Insertion and extraction can be done without any use of other tools; Safety Clamps can be provided to increase safety.

ER Extractable Probe could be extracted or inserted while the plant is working.

More technical details