Pressure Transducers

Pressure Transducers

A pressure transducer, or pressure transmitter, is an analog electrical device typically used to measure pressure. One of the most common types of pressure sensors is the strain-gage base transducer. This article will provide an overview of the various types of sensors and how they work.


A sensor measure pressure by transforming it into an electrical signal. This is done through a process of physical deformation of strain gages, which are easy to install and are placed inside the diaphragm of the pressure transducer. When pressure is being applied to the sensor, the diaphragm will flex inwards and consequently strain the gages. This will produce a change in electrical resistance proportional to the applied pressure.

The Electrical Output of Pressure Transducers

The three different types are millivolt, amplified voltage or 4-20mA. This article explains how to wire pressure transducers based on their output.

After you measure the electric output, it is necessary to convert it into an engineering unit, such as PSI or bars.

This is used across various industries, including the oil and gas industry, water management, petrochemical manufacturers, the food industry, etc.


A millivolt transducer is the most economical type of pressure transducer. This particular unit produces values around 30mV, but the actual output will be dependent on the power input by the excitation or input.

The output signal produced by a millivolt transducer is directly dependent on the excitation level. This means that when the excitation changes, so will the output signal. A regulated power supply would be a good choice to provide power to millivolt transducers because they don’t have much of an excitation level, to begin with. And as such, a noisy environment shouldn’t affect them.

It is a good practice to keep the distance between the transducer and the readout instrument relatively short.

Voltage Output Pressure Transducers Models

Our voltage output transducer is a device that provides much higher outputs than a millivolt transducer. Typical outputs are 0-5 volts or 0-10 volts.

Although the output of the transducer is specific to the model, it is not a direct function of excitation. This means unregulated power supplies often suffice as long as they fall within a specified power range.

This higher level output means millivolt transducers are more susceptible to electrical noise. Translation: they can’t be used as widely as digital transducers.

4-20 mA Output Pressure Transducers Models

Our 4-20 mA pressure sensors are a great addition to any fluid monitoring system.

The 4-20mA signal is most immune to electrical noise and wire resistance, so these types of transducers are best-suited for long-distance pressure measurements.

Transducers are often used in power applications, where the lead wire must be 1000 feet or more.

Other Types of Pressure Sensors at RAAH International

Pressure transducers come in many shapes and sizes, but they all share a similar set of technical capabilities. There are even specialized pressure transducers that are based on their design.

Pressure sensors are divided into four main types based on the way in which pressure is sensed:

  1. Strain Gauge Pressure Transducers
  2. Capacitance Pressure Transducers
  3. Potentiometric Pressure Transducers
  4. Resonant Wire Pressure Transducers

Selecting Pressure Transducer

Need help deciding what type of pressure transducer or transmitter you need?

Board Mountable Pressure Transducers

Our board-mountable pressure transducers are perfect for businesses with heavy demands on their equipment.

PC board mountable pressure transducers are typically small, economical, and designed to be mounted on a PC board. They can also be integrated into other products.

General Transducers

Pressure transducers have a variety of purposes but are typically used in high-volume manufacturing applications.

Heavy Duty/Industrial Pressure Transducers

Heavy-duty pressure transducers are designed to measure pressure changes at high pressures. These sensors are often used in industrial environments.

Heavy Duty/Industrial Pressure transducers are built to handle heavy environments where things might get a little messy. They also have a scalable 4-20mA output that provides much better immunity to electrical noise when compared to other pressure transducers.

High Stability/High Accuracy Pressure Transducers

Pressure transducers can vary in accuracy, depending on the application. For example, if you need to measure pressure with high precision and accuracy, you may have to choose a high-stability, high-accuracy pressure transducer. With that said, these are much more expensive than general-purpose transducers.

Flush-Diaphragm Pressure Transducers

While flush diaphragm pressure transducers are ideal for some applications, such as monitoring the pressure of viscous fluids, there are others where it’s not so desirable. Flush diaphragm transducers will not work well with food or liquid processes that have a high viscosity.

Special Transducers

We offer a variety of pressure transducers with features that are perfect for your special needs. Our pressure transducers can be used in very high or low temperatures, submersible conditions, or even in a barometric setup. Not only that, they come equipped with digital communications output or wireless outputs so they can meet your every need.

Contact Us

When it comes to pressure measurement, stability and accuracy are what matter the most. An engineered type of transducer that is specifically used for transmission of a high-frequency signal. To learn more about the pricing of pressure sensors, get in touch with our field experts at RAAH International.