Calibration in China
At the KROHNE location in Chengde, China, variable area and vortex flowmeters are manufactured.
Like calibration in Germany, flowmeters here are also calibrated using reference flowmeters. Depending on the required measuring accuracy, more precise glasses or even electromagnetic flowmeters can be used. The elevated tank shown in Figure 8.1 enables the calibration of H250 variable area flowmeters at any installation site.
Small flows can be measured using a gravimetric measuring system. In this case, the flowing volume is traced back to a mass and density of the product.
Electromagnetic flowmeters and mass flowmeters are both manufactured at the KROHNE site in Shanghai. Here too, devices with nominal sizes up to DN 3000 and flow rates up to 18,000m/h can be calibrated. The close technical dependence on the calibration rig technology of KROHNE Altometer makes the high standard of calibration of KROHNE flowmeters possible.
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.