Many of us working in the fluid power industry consider ourselves mechanically inclined. Concepts of pressure, force, flow, and torque are second nature. But the continuing influx of electronic components—especially transducers—into hydraulic and pneumatic systems makes knowledge of electrical terminology and concepts essential to job performance.
Pressure transducers serve the same function as a pressure gauge—the difference being that the gauge offers a visual indication of pressure whereas a transducer provides an electrical signal indicative of pressure. (Some pressure transducers have a digital readout to also provide visual indication.) To help explain some of the most common concerns surrounding pressure sensors, direct answers are given to the following frequently asked questions:
Is there a difference between a pressure transducer and a pressure transmitter?
When these terms originated, a distinct difference existed between the two. A transmitter was referred to as an instrument with a current signal, such as 4 to 20 mA, whereas a transducer had a voltage signal ranging from 0 to 10 V dc. Over time, these terms have become interchangeable. So in general, no, there is no difference, but the answer may depend on whom you talk to.
One problem with pressure transducers is that they normally don’t show you pressure. Is there a way to see what the pressure is without having to install a new indicating transducer?
Of course, Noshok and other manufacturers offer transducers with an LED indicator to display pressure right on the transducer. But for existing applications, Noshok’s 1800 series digital indicator can easily be installed between a transducer’s DIN 43650A output connector and cable. In fact, it can work with any brand transducer with a DIN 43650A connector and sufficient power-supply voltage to drive all instruments in the loop.
Another advantage is that it can be transferred from one transducer to another. Therefore, if a transducer becomes damaged, the indicator can be reused on a new transducer, provided it also has the DIN 43650A connector.