Three specific types of errors have a negative impact on pressure sensor accuracy. This easy-to-understand video from WIKA explains the difference between zero-point errors, span errors, and non-linearity.
Inaccuracies in pressure instrumentation occur when the output signal deviates from the desired measuring result. When pressure readings are higher or lower than actual, you risk the performance and safety of your application. Therefore, it is important to recognize the errors – and to understand how they come about.
Using a simple analogy and easy-to-follow animation, this short video from WIKA describes the three main errors that affect pressure sensor accuracy:
- Zero-point error – The start of the measuring range is too high or too low (this is the zero offset), thus shifting the entire scale up or down by that zero offset value.
- Span error – The distances between the individual divisions (the span) from the zero point to the full-scale value are even but wrong, which has the effect of magnifying errors at the upper end of the scale.
- Non-linearity – The distances between the individual divisions from the zero point to the full-scale value are not even (non-linear), thus making the ideal straight line into a curve.
Some users use the terms pressure sensor accuracy and pressure sensor non-linearity interchangeably. But as the video demonstrates, non-linearity is just one of the errors that cause inaccuracies. And in real life, more than one error can occur at the same time – canceling each other out or resulting in larger inaccuracies.
Watch this video for a straightforward and accessible explanation of the main types of errors that affect pressure sensor accuracy. For more information about WIKA USA’s complete line of pressure measurement products, see our website or contact our experts.