HART

Calibration can simply be described as an activity where the instrument under test is compared with a reference. At the simplest level, calibration is the comparison of two measurements, one of a known standard and one of a similar standard with another device. The device with known level is called standard. The second device is the unit under test.

Calibration is often required on a new instrument or when a time interval has elapsed. Furthermore, calibration is usually performed when an instrument has been subjected to an unexpected shock which may have taken it out of specification. For this, calibrators that are simple to use and within everyone's reach are needed.