Calibration in France
At the KROHNE site in Romans, France, level transmitters are manufactured and calibrated.
TDR level transmitters (Time Domain Reflectory /guided microwaves) in the OPTIFLEX series are calibrated on 30m tracks. In the process, the reflector plate can be automatically positioned on the required calibration point. High demands are placed on the measurement process, both in terms of measurement uncertainty as well as the repeatability of the results. With the help of a tensioning device, the cable is stretched to its optimal length. Due to the parallel setup of two tracks, installation times for the OPTIFLEX devices are minimised. Another, manually-operated calibration rig makes calibration possible at distances up to 40m.
The calibration of FMCW level transmitters (Frequency Modulated Continous Wave/non-contact radar waves) in the OPTIWAVE series takes place in a calibration tunnel lined with high-quality absorbent material. As many measuring points as necessary for the calibration can be set using automatic traversing. For calibrations of up to 5m, a multi-position calibration rig is available. Device calibration takes place vertically with the help of two moving targets.
Influences in practical use
When you consider the calibration values of a flowmeter, ideally they should not deviate from the measuring values in the application.
References and measurement standards
Calibration usually takes place with the help of a “more accurate” measuring device. This device is referred to as the reference, the measurement standard or superior measurement standard.
Definitions
Any error of measurement detected during calibration as a result of repeat measurements is the so-called systematic measurement error.