What is a pressure transmitter?

What is a pressure transmitter ?

A pressure transmitter is a device capable of measuring applied pressure. The pressure transmitter converts physical pressure into an electrical signal.

A pressure transmitter, often referred to as a pressure transducer or transmitter, is a device used to measure and convert mechanical or hydraulic pressure into an electrical signal.

The electrical signal can be used to display the pressure measurement on a display, or sent to a controller, PLC or data acquisition system for further processing.

This pressure measurement can be used for a variety of purposes, including fluid control, fluid monitoring and air pressure measurement.

The pressure units units include pascal (Pa), bar, atmosphere (atm), and psi (pounds per square inch), each unit being chosen according to the specific application and measurement scale required.

Piezoresistive pressure sensor

The most common type of pressure transmitter is the piezoresistive pressure transmitter .
These pressure transmitters are constructed from a resistive material which changes resistance in response to applied pressure.
This change in resistance can be measured and converted into a digital signal, giving the user an overview of the situation.

Piezoresistive pressure transmitters can be found in a wide variety of applications, from automotive to medical devices.

Capacitive pressure transmitter

Capacitive pressure transmitters are another type of transmitter. These sensors use the capacitance principle to measure applied pressure. Capacitance is a measure of the ability of two conductors to store an electrical charge. In a capacitive pressure transmitter , the receiver of the pressure measurement is the diaphragm. Diaphragm materials can be stainless steel, hastelloy C or tantalum, for example. When pressure is applied to the surface of the diaphragm, the deformation changes the distance between two capacitances, via a filling liquid. This change in capacitance can be measured and converted into a digital signal.

These capacitive pressure transmitters are often used, for example, in applications in the oil and gas, energy, food and beverage, water and environment, cement and paper and board industries.

Thin-film resistive pressure transmitter

Thin-film resistive pressure transmitters are another type of transmitter. These transmitters use a very thin layer of resistive material to measure the applied pressure. This layer is usually only a few hundred nanometers thick, making it highly sensitive to changes in pressure.

Thin-film resistive transmitters are often used in industrial solutions, where accuracy and precision are essential.

Optical pressure sensor

Another type of transmitter is pressure transmitters . These sensors use optical fibers to measure applied pressure. The principle behind these sensors is quite simple: as light passes through a fiber, its properties (such as wavelength) change according to the pressure exerted on the fiber. By measuring the change in wavelength, pressure can be accurately determined.

The fibre optic pressure transmitters are often used in pressure measurement applications such as hydraulic systems and gas pipelines.

Hydrostatic pressure transmitter for level measurement

Hydrostatic pressure transmitters operate on the hydrostatic principle to provide a pressure measurement proportional to the applied head.

In a hydrostatic pressure transmitter, the fluid is contained in a sealed chamber. When pressure is applied to the chamber diaphragm, it deforms the chamber walls, resulting in a change in the fluid height measurement. This change can be measured and converted into a digital signal.

The hydrostatic pressure transmitter is often used in process and level measurement solutions on tanks and reservoirs.

What is special about an industrial pressure transmitter ?

Industrial pressure transmitters are generally more accurate and have a longer service life than pressure transmitters consumer products.

They are also more expensive, but this is often worthwhile for applications where precise measurement is essential.

An industrial pressure transmitter can be used to measure fluid or gas pressure in a variety of environments, including factories, laboratories and other industrial facilities.

For critical pressure applications, annual calibration of pressure transmitters may be required.