
Pressure Sensors & Transmitters

Pressure sensors and transmitters are critical components in various industrial processes, automation systems, and even in everyday devices like vehicles or home appliances.
A pressure sensor is a device that can measure pressure, converting the physical quantity into an analog or digital signal that can be read by a user or a computing system. There are different types of pressure sensors, including strain gauge, piezoelectric, and capacitive sensors, each of which operates on a different principle and is suitable for different kinds of applications.
Pressure transmitters, on the other hand, are somewhat more complex devices that include a pressure sensor, but also additional electronics to generate a standardized output signal, typically an analog electrical voltage or current signal (like 4-20 mA) that can be transmitted over some distance and interpreted by other devices, such as a PLC (Programmable Logic Controller) or a process control system. Pressure transmitters are often used in industrial and manufacturing processes where pressure data needs to be sent to a central control system for monitoring or control purposes.
Products
More Information about Pressure Sensors and Transmitters
A differential pressure transmitter is a special type of pressure transmitter that measures the difference in pressure between two points. This is useful in applications such as flow measurement, where the pressure drop across a restriction can be used to calculate the flow rate.
An important concept related to pressure sensors and transmitters is the pressure range, which refers to the minimum and maximum pressures that the device can accurately measure. Some devices are designed to measure very low pressures, others very high pressures, and some can measure a wide range of pressures.
Pressure can be measured in various ways, such as gauge pressure, which measures pressure relative to atmospheric pressure, or absolute pressure, which measures pressure relative to a perfect vacuum. The specific pressure type a sensor or transmitter is designed to measure depends on the application it is intended for.
In terms of their working, a pressure sensor usually works by detecting the strain (deformation) caused by pressure on a sensing element (such as a diaphragm or a piezoresistive element), and then converting this strain into an electrical signal. The electrical signal can then be conditioned, amplified, and converted to a digital signal, if necessary, by additional circuitry within the sensor or transmitter.
In the case of a pressure transmitter, the output signal is typically designed to be robust against noise and capable of being transmitted over long distances. This is important for industrial applications, where the transmitter may be located some distance from the control equipment, and where electrical noise from motors and other equipment can interfere with the signal.
FAQs
What are pressure transducers?
Pressure transducers, also known as pressure sensors or pressure transmitters, are devices used to convert pressure into an analog or digital signal that can be measured. This conversion happens when a physical force, typically pressure, is applied on the transducer, resulting in a change in its physical properties. This change is then converted into an electrical signal.
What are pressure switches?
Pressure switches are used in various systems and applications to control the pressure of gases or liquids. They work by activating or deactivating a switch output when a set pressure point or range is reached. They can be designed to make contact either on pressure rise or on pressure fall.
Instrumentation: Elements & Transmitters
2 pieces of hardware used in modern day instrumentation: measuring elements and transmitters.
Measuring Elements
Measuring elements are the part of the device that performs the measurement. For example, the measuring element of a pressure transducer is the part that is actually lowered into a tank that will take a pressure measurement. The measuring element of a flow meter is the part that actually measures the flow and an RTD or thermocouple takes the temperature measurement.
Transmitters
Transmitters collect information from measuring elements and sends the information to where it is needed. The transmitter interfaces with the measuring element and interprets the information. It then sends that information to a PLC, RTU or some other type of control unit. In many cases, the transmitter has the ability to communicate the information via multiple communication protocols. This may be necessary when the measuring element does not send the same type of signal that is needed by the controller. For example, it may be necessary to convert a temperature reading from a thermocouple to a 420 milliamp signal that can be received by a local PLC.