Industrial pressure sensors - principle of operation, types and application

Pressure is one of the basic measurements performed in the vast majority of industrial and manufacturing facilities. The primary functions of such sensors are to measure pressure and transmit the collected information to external devices.

Due to the ability of most sensors to convert an input signal into an analog or digital electrical signal, they are also often called transducers.

Principle of operation of industrial pressure sensors

Pressure sensors work like a strain gauge by using the deformation of a membrane made of silicone, metal or ceramic. Pressure is a non-electrical signal, so it is necessary to convert these values into signals that electrical devices can easily use. The precise construction of membrane pressure sensors allows them to work efficiently with electronic circuits, so that when a flexible element is deformed, the measured value is immediately converted into an electrical signal proportional to the amount of pressure applied.

The most popular solutions are sensors with silicon and stainless steel membranes. The first solution increases the pressure resistance of the membrane, so the lifetime of such sensors increases significantly. Additionally, silicon can be combined with other materials, e.g. ceramics, to obtain new properties that increase the transmitters' performance. The second solution can be found in sensors that operate in harsh environments and heavy industry.

Types of industrial pressure sensors

There are many types of pressure transmitters on the market. The choice of a particular solution depends on the end application, but above all on the measuring system. A very popular solution are differential sensors, which measure the pressure from two sources on a membrane. The deflection resulting from this difference gives information about the relationship between the pressure of the measured gas and the external pressure.

Relative pressure sensors, which measure pressure relative to vacuum or atmospheric pressure, are another option. Absolute pressure sensors that compare the measurement with vacuum exclude the influence of atmospheric pressure on the measurement. Such solutions are often found in applications for checking the tightness of sealed tanks.

Technical information about industrial pressure sensors

Before purchasing a sensor for the solution, it is worth to get acquainted with several parameters that can be helpful in selecting the right element:

Measuring range
Several standards are used in industry to measure analog signals. The standards used in pressure transmitters are 4 - 20 mA, 0 - 10 V and 0.5 - 4.5 V. 
Because of the need to choose the right measurement accuracy, most facilities use sensors that have the ability to switch between different ranges.

Minimum pressure
Each transmitter has a lower measurement limit for which it will show the correct pressure values. With a measurement range of 4 - 20 mA, this will be 0 bar for 4 mA.

Maximum pressure
This is the upper measurement limit of the sensor. When we have the minimum and maximum pressure, we are able to select a suitable sensor with this measurement range.

Power supply
Determining the type and value of the power supply is critical for any sensor. The industry standard is 24 VDC.

Use of industrial pressure sensors

Pressure sensors can be found in many advanced applications and industries. Pressure transmitters are commonly used in:

• Manufacturing industry;
• Heavy industry – military and aeronautics;
• Hydraulic industry;
• Automotive industry;
• Medical and chemical industry;
• HVAC systems – heating, ventilation, air conditioning.

Despite their small size, pressure sensors are key elements of every automation system. They are able to monitor the course of processes and work of devices and installations, allowing for quick elimination of any failures and damages in production processes. With many years of experience in distribution of products and devices for automation, Dacpol offers the best solutions to meet customer requirements. Our offer includes a wide range of pressure sensors for industrial applications. Our specialists will help you choose the right solution and answer all your questions.