How are various types of flowmeters calibrated? The calibration medium is different from the operating medium
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The last edit to this post was made by small Q Timekeeping on 2016-3-10 at 10:29. I would like to ask everyone: How are common flow meters such as electromagnetic flow meters, vortex flow meters, and mass flow meters calibrated to determine their accuracy? Water is used during calibration, while flowmeters are designed to operate with the medium under specific temperature and pressure conditions. With a different medium, can the flow meter readings still be accurate?
**There are metrological verification standards, and all verifications are carried out in accordance with these standards, so there are no issues.
Assuming the calibration value is 5000 kg/H (water), can my electromagnetic flowmeter display 5000 kg/h as well? But my electromagnetic flowmeter wasn’t designed for use with water – do I need to change its parameters?»
Electromagnetic flowmeters and vortex flowmeters are volume flowmeters; during calibration, water is used to measure the volume flow, and the same applies in practical applications as well. If a mass flow rate is displayed, it is obtained after performing a density conversion. Water is also used for calibrating mass flow meters, and the density is corrected automatically in practical applications.
So with the original electromagnetic flowmeter, even if the medium changes, is the measured volume flow rate still accurate?
Yes, an electromagnetic flowmeter measures the flow velocity, and the flow rate is obtained through internal calculations
Electromagnetic and vortex flow meters are generally not calibrated; they can be found everywhere in the plant, making it impossible to calibrate them. The quality will be calibrated at a qualified testing center; all you need to do is provide the specification sheet, and they will take care of the rest for you.
Mm. Actually, I just want to learn a bit about which flow meters on-site can still provide accurate measurements after having their working medium changed (without taking pressure and temperature effects into account). In this way, sometimes my flow meters can be interchanged. If the water used during calibration allows the flow meter to accurately measure the flow rate, then it means my flow meters can be interchanged
In the metrology department, water is used for calibrating flowmeters; I’ve never seen any other medium being used, though it’s possible that such cases do exist. In some situations, conversion is necessary, while in others, like with mass flow, calibration can be carried out directly……
If possible, it is still recommended to use an oil gauge; many flow meters pass the test with a water gauge but fail when using an oil gauge.
In addition to mass flow, there is also a water calibration coefficient; generally, for calibrating flow meters, water is used for this purpose