Pressure transducers come with a range of voltage output options. Thanks to advancements in controllers that receive transducer signals, there is greater flexibility available in the market. There are slight differences among many of the output options on the market. While some were developed to maintain competitive edges through customized products, others have sound reasoning behind them. All the outputs discussed here require a minimum power supply of 10VDC (with 0-10V and 1-10V outputs needing 12VDC). A 0.5-4.5V ratiometric output signal is traditionally powered by a 5VDC regulated supply, though other variations are feasible. Similarly, millivolt output signals possess their own distinct features and advantages. The following is a concise introduction to amplified voltage pressure transducers.
Traditional pressure transducer outputs include 0-5V and 0-10V signals. Popularized in Europe, zero-based output signals characterize standard gauge pressure transducers, which generate no output at zero pressure. Transducers with such zero-based outputs are available in both three-wire and four-wire configurations. A key advantage of the 0-10V signal lies in its doubled measurement span compared to the 0-5V signal. However, a major drawback of any zero-based output is the absence of a signal at zero pressure. In cases where the transducer experiences issues—such as a cut wire, a damaged sensing element, or electronic components exposed to over-voltage—the sensor will fail to produce any output, making it impossible to detect such faults.
For instance, consider a pressure transducer measuring water pressure: it will output 0V when there is no pressure in the pipeline. When pressure is detected, it sends a signal to activate the pump. Since a 0V output indicates both the normal "no pressure" state and fault conditions (e.g., wiring damage or component failure), there is no means to distinguish between the two scenarios. Consequently, the pump may not receive the signal to operate, potentially leading to a flooding incident.
VOLTAGE AT ZERO PRESSURE
There are numerous variations and customizable options available for pressure transducers that provide an output signal at 0 PSI. For example, TE Connectivity offers several non-zero based output ranges, including 1-5V, 1-6V, 0.25-5V, and 1-10V. Among these, the 1-5V output is the most widely used in the industry. This configuration includes the safety benefit of producing a 1-volt output at zero pressure, along with a 4-volt span for measuring pressure.
The 1-6V and 1-10V output ranges are favored by engineers who desire a voltage range similar in magnitude to traditional zero-based outputs (such as 0-5V or 0-10V), but with the added advantage of having a measurable signal even at zero pressure.
A somewhat unique option is the 0.5-2.5V output range. This configuration is particularly useful in remote telemetry applications, where power consumption is a critical consideration. In environments such as remote oil fields or construction sites, where power is often supplied by lithium-ion batteries or solar panels, minimizing power usage is essential to extend equipment life. The 0.5V signal at 0 PSI provides sufficient indication that the transducer is functioning, while the 2.5V span offers adequate resolution for accurate pressure or level measurement.
