Pressure Transducers Explained
In industrial settings that deal in pressurized fluids and gasses, pressure matters. That’s why, from power plant steam piping to natural gas dispensing equipment, pressure transducers are used to track, measure and alter the pressure within certain fluid and gaseous systems.
What Is a Pressure Transducer?
A pressure transducer, like a pressure transmitter, is a key component in monitoring and controlling fluid pressure. With an appropriate power source, a pressure transducer can send out an electrical signal in a measured proportion to the pressure that’s applied to it, usually through a diaphragm that’s connected to a resistor. Although pressure transducers and pressure transmitters operate in nearly the same way and perform similar functions, transducers send out their signals in millivolts or volts, while transmitters send out their signals in milliamps.
Most transducers are manufactured to send an output signal that is linearly proportionate to the pressure being applied to them. However, variables — such as altitude and temperature — can affect their output.
How Does a Pressure Transducer Work?
The majority of transducers have a pressure-sensitive element that reacts to pressure entering through the transducer’s pressure port. As the sensing element or diaphragm is deflected due to the pressure’s force, it moves in relation to a resistor or capacitor plate. This, in turn, sends an output signal that is determined by the varying tension between the input signal, diaphragm position and core resistance.
While most transducers are designed to produce a linear output in relation to the pressures they encounter, certain external variables can have an impact on their output signals. Nothing affects transducers more than temperature. That’s why almost all transducers are manufactured to be functionally accurate within a given temperature range. This sensitivity is due to the fact that as temperatures increase or decrease, there’s a resulting expansion or contraction in fluids and materials, which can change both the transducer’s mechanical and electrical properties and alter its calibration.
Different Types of Pressure Transducers and Their Applications
The types of transducers and their applications are as varied as the many industries that employ them. Four factors help determine which type of pressure transducer or transmitter needs to be installed in any given system:
- The particular device (e.g. programmable controller, microprocessor, panel meter) to which the transducer will be sending its output signal.
- The amount of EMI (electromagnetic interference) that will be encountered, such as in welding, power line and motor applications.
- The overall distance from the original pressure measurement and output signal to the device that will eventually receive the signal. Note: Transducers are the optimum choice for shorter distances, while transmitters are typically used in applications requiring signal sending over longer distances.
- The cost of the overall system and its installation.
Transducers can be found in use in HVAC compressors and filtering, robotic and automation equipment, industrial transport and lifts, hydraulic feedback in weighing/scale systems and heavy-duty vehicles and power plants and fluid fuel systems.
When it comes to expert advice on transducers, a large inventory, prompt delivery and superior technical support, look no further than SEMCOR. We’re your leading supplier of pressure transducers and transmitters from top manufacturers you can trust. Contact our sales and service staff for more product information and answers to all of your questions.