Expert’s answer: Pressure transmitter basics

Good question, we’re now talking about pressure transmitter basics. Pressure sensors translate pressure data into electrical current. Then a data analyzer reads that current for your system. So let’s talk about four types of sensor here.

So first of all, we have the ceramic cell. It has a conductive surface that charges a capacitor. When a force applies pressure, the charge increases or decreases. And that depends on the pressure applied. Closed cells measure absolute pressure, and open cells measure gauge pressure.

In addition, you can use strain gauges. They measure hydrostatic pressure in tanks using a Wheatstone bridge. That means that under pressure, the strain gauge deforms. This, again, produces a change in resistance.

We also have metallic diaphragms. They use semiconductors to sense changes in resistance according to the change in pressure in the sampling chamber.

Finally, Yokogawa’s silicon resonant sensors use micro-electro-mechanical systems (MEMS) technology. Here, two resonators pick up frequency shifts when tension or compression occurs. Then, this sensor connects to the sampling chamber of the transmitter.

Also, different connections and primary elements link the process medium and the actual sensors. Coplanar™ transmitters by Emerson can connect to several types of manifolds. Plus, it can connect to valves without changing the setup.

Want more information? In that case, check out these links for more info:

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