A pressure transducer can directly measure the force of gas or liquid, and convert the value into an electrical signal. Pressure transducers typically include a sensing diaphragm capable of responding to changes in pressure. Pressure pushes on this diaphragm, changing its position, and this changes the inductance of sensing coils mounted opposite the sensing diaphragm. The coils are excited with an AC waveform and the resulting change in electrical impedance represents the applied pressure. The electrical output of the coils is converted to a DC signal.
Pressure Transducers – Classifications
Pressure transducers come in a variety of shapes, sizes, and output signal types. In addition to a DC voltage output, current signals are often used for electrically noisy environments commonly present in industrial applications. A 4 to 20 mA signal has been adopted as the industry standard and the current signals can be sent accurately beyond 1,000 feet. All pressure transducers are generally characterized by their pressure measurement range. They are also classified by accuracy, errors due to temperature change, and the amount of static pressure the sensor can tolerate. Temperature always affects transducer accuracy and most transducers have a scheme to correct for ambient temperature changes Resolution is another characteristic used to evaluate a pressure transducer, and this is defined as the smallest amount of pressure change that can be detected – typically a function of the signal-to-noise ratio of the output.
Electromagnetic interference (EMI), can also affect transducers. Some units are protected against EMI effects, but only up to certain intensities. Materials used to make the sensors vary, and include plastic, silicon, stainless steel, or epoxies. Epoxies can be adversely affected by certain fluids under pressure.
Some pressure sensors are mounted to a circuit board with contacts to secure a solid connection. Others are designed for industrial environments and sturdily constructed with weatherproof enclosures. If the device is for general use, it is likely to have a standard design that allows it to easily connect to commonly used receiving devices such as computers, programmable controllers and panel meters. The costlier transducers are known for their high-accuracy readings and low rates of error as a percentage of full scale range. At Validyne, we offer many different configurations to meet your exact requirements.
Types of Transducers
At Validyne, we serve several major markets and carry a variety of transducers, which include differential pressure sensors, gage pressure transducers, USB pressure transducers, electronic pressure manometers, low pressure transducers, OEM pressure sensors, and more.
Transducers perform a critical job in every industry, especially in automation and control. Transducers used in aircraft or healthcare applications have lives depending on reliable and accurate performance.