How do you calibrate a length measuring device?

Although it is not mandatory, you might want to have your length measuring device calibrated. What is ‘calibration’ exactly and why should you do it? Calibration means that the measured value displayed by a measuring device is compared to a reference value. It can be used to determine the accuracy of measurements produced by a length measuring device. Calibrated devices are issued with a calibration certificate. Venrooy’s length measuring devices are calibrated at an external calibration centre.