What are the Benefits of Zero and Span Adjustability
Your pressure sensors are an important part of your application, ensuring accurate and reliable measurements and the safety of your process and its operators. To keep your processes working properly, recalibration of your sensors may be necessary over time.
Sensors can degrade over time as components are exposed to wear, temperature and cycling. This can lead to a loss of stability and drift in the output signal of the sensor away from its published specification.
Using sensors that cannot be recalibrated would require the replacement of the sensor once it drifted outside of its specifications and its output signal was no longer reliable. This could cause your critical application to shut down temporarily until the sensor can be replaced.
A sensor that can be recalibrated will not only prolong the sensor’s life but will have your process back up and running in no time at all. This article will discuss zero and span adjustability and the benefits it can provide to your process.
What is Zero and Span Adjustability?
Zero and span adjustability is used to recalibrate the output of the sensor at the extremes of its calibrated range. Typically, these adjustments are made through potentiometers or other adjustment tools (i.e., a reed switch with a magnet) to finetune the output signal at both the zero and full span measurement points.
Adjusting the output signal at both zero and span corrects the errors in the output signal due to the drift of the sensor, which can be caused by its duration of service or the number of pressure cycles. How often the output of the unit should be recalibrated depends on the application or your calibration requirements.
What are the Benefits?
Zero and span adjustability allows the end-user to adjust the pressure sensor’s output at their facility or in the field for minimal downtime of crucial applications. Another benefit of recalibrating a sensor's zero and span is that it can prolong the life of the pressure sensor.
All of this saves time and money by eliminating the inconvenience of having to send the sensor back to the manufacturer or a calibration lab for recalibration. In addition, it ensures the end user’s process remains as accurate as when the sensor was originally installed.
What are the Drawbacks?
The main drawback is that zero and span adjustment only addresses the output signal at the zero point and full span of the device. However, if there is any signal offset between these points, it cannot be adjusted. This may or may not be important to an end-user depending on the accuracy requirements of the application.
So, if the accuracy across the entire range of the pressure sensor is more important to a user, the pressure sensor must either be replaced or returned to the manufacturer for repair and recalibration.