Pressure sensors for corrosive liquids and gases

Pressure sensors for use with corrosive media often feature housings made from stainless steel or plastics such as PVDF, PVC or PPS. The sensor elements themselves are typically ceramic.

However, TM Sensor use a stainless steel diaphragm backed by silicon oil that transfers pressure to the sensing element.

The pressure sensors will usually specify a suitable pressure range (for example, 200 mbar–35 bar). Certain sensors may be able to measure both absolute and gauge pressure (see above), with a pressure range specified for each. Some sensors can be configured to measure negative pressure as well as positive.

Some sensors for corrosive media are temperature-compensated, so their readings are not affected by changes in media temperature.

Sensors will also specify the voltage output that they use to indicate pressure changes, and their output at zero pressure (for example, 100mV).

In some cases, the O-ring used to seal the ceramic diaphragm to the body of the sensor can be made from different materials, such as fluorocarbon plastomer (which resists mineral acids, petroleum oil, salt solutions and chlorinated hydrocarbons), nitrile rubber (which resists paraffin-based materials, fatty acids, glycerines or alcohols) or EPDM - ethylene propylene diene monomer (which resists many acids and alkalis).