Zeroing

Zeroing is the act of placing a sensor into a state where the output condition is known to be zero and changing the measurement’s offset variable so that the sensor output reads as zero. By measuring the output of the sensor in this specialized condition (the zero condition), the offset variable will be changed to ensure that the known zero condition results in a measurement value of zero. Note that this process only changes the offset variable that is shared between the measurement instruction and the FieldCal() instruction. The multiplier is unaffected.

A simple example of zeroing would be taking off all items from a scale designed to measure the mass of objects. With nothing on the scale, this is the condition in which the scale should give a “zero” reading for its output. The calibration is triggered and the offset is adjusted to ensure the scale gives a zero reading for that condition.

To perform a zeroing calibration, use an argument of 0 (the number zero) for the calibration type in the FieldCal() instruction of your CRBasic program. The Calibration Wizard can be used to calculate and apply the proper offset while the program is running in the datalogger, or code can be configured within the CRBasic program to trigger the zeroing event based on flags or other user-defined conditions that occur while the program runs.