A digital pressure sensor is calibrated to display readings correctly over a range of 0 to 100 psi. If the display shows 2 psi when the actual pressure is 0 psi, what type of error is this?

The scenario presented describes a situation where the digital pressure sensor is expected to read 0 psi at an actual pressure of 0 psi, but it instead displays 2 psi. This indicates that there is a consistent deviation from the true reading at the zero point of the sensor's calibration.

This type of error is referred to as a zero shift error, which occurs when a sensor displays a value that is offset from the actual zero reference point when it should ideally read zero. In this case, the sensor is not calibrated properly at the baseline (0 psi), leading to an incorrect reading even when there is no pressure applied.

Understanding zero shift error is crucial because it can significantly affect the accuracy of measurements. If a sensor is not properly zeroed, all subsequent readings may also be inaccurately shifted by the same amount, leading to larger inaccuracies in the overall measurement range. Recognizing and correcting for zero shift errors is an essential step in maintaining the integrity and reliability of measurement instruments.