Pressure transmitters are versatile devices based on a simple working principle. We can use them to measure more than pressure, like level and flow. There are a wide variety of pressure transmitters in the market and each one varies as per the applications required.

To know more about pressure measurement calibration, you can read the Visaya Article on Pressure Measurement and Calibration

The pressure transmitter’s working principle

Like other transmitters, a pressure transmitter consists of electronics connected to a sensor. We can find transmitters with many types of sensors on the market – capacitive, piezo-electric, resonant silicon, and more. This article will focus on the capacitive sensor, as it is the most common, although that doesn’t make it the best.

B+B Thermo-Technik GmbH
DRTR-AL-20MA for absolute pressure Compact pressure transmitter in aluminium for liquid and gases with G1/4" connection
in the shop from 77 €
DRTR-AL-20MA

So pressure applied to capacitive cells will produce a change in the capacitance of the sensor. This change will affect the oscillator frequency, and the pressure transmitter will detect this change. Then the transmitter translates this data into a standard output signal that we can read.

Using a local setup or a handheld, you can adjust the transmitter, changing information like the unit, measuring range, and output.

If you would like to know more about using a pressure transmitter with a HART communicator, click here.

More than just a pressure device

Pressure transmitters can measure more than pressure. Using different primary elements, you can measure flow through with a differential pressure transmitter. You can also measure the level of closed and open tanks. For that, you can use a differential pressure transmitter with differential, absolute, or gauge pressure.

Today we have other principles that work as well or better to measure flow or level. However, you’ll still find pressure devices across many segments, processes, and measurements. You can find out more about these applications for differential pressure from this article.

Pressure transmitter installation

You can install a pressure transmitter in all kinds of applications, but all of these take different installations. For example, say you want to measure a level with a differential pressure device. If you have an open tank, then you can install the device on the bottom of the tank using a flange with a filled-sealed container.

If you want to measure flow with a pitot, then you can install the device using a single flange direct to the pitot. Or if you have a steam flow meter with an orifice plate, then you’ll want to install your transmitter remotely with a seal pot between the device and the process.

B+B Thermo-Technik GmbH
DRTR-ED-10V for absolute pressure Compact pressure transmitter in stainless steel for liquid and gases with G1/4" connection
in the shop from 80 €
DRTR-ED-10V-A

With so many options, the easiest, cheapest, and most reliable installation will depend on your process. Of course, many of you knew I’d say that, but a few didn’t.

To know more about pressure transmitters, you can get in touch with our engineers!

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