Uncertainty calculation for electromagnetic flowmeter for drinking water?
An electromagnetic flowmeter is made up of 2 elements:
- The sensor installed on the pipe
- The electronics (remote or integrated into the sensor)
More than one electronic cards can be assigned to a sensor which provides more or less precision.
For example, with Krohne’s OPTIFLUX 2000 sensor, the following electronics has an uncertainty factor in the order of:
- 0.5% for IFC50
- 0.3% for IFC100
- 0.2% for IFC300
Obviously this degree of uncertainty does not extend to the entire measurement capacity, but it is generally respected in the case of smaller flows.
The price of the electronics is also inversely proportional to the uncertainty. The choice of hardware therefore depends on the intended use..
For process control, without metered sales, a margin of uncertainty of 0.5% is perfectly acceptable, as is the case for small volumes. But when the volumes become significant, either for sale or tariff, it is in everyone’s interest to ensure the lowest level of uncertainty.