Final answer:
Calibrating an orifice meter establishes its accuracy in flow rate measurement by determining its flow coefficient and ensuring the calculation of pressure drop across the orifice is correct.
Step-by-step explanation:
The purpose of calibrating an orifice meter is to ensure accurate measurement of flow rate. Calibration involves comparing the readings from the meter with a known standard or another instrument that has been previously calibrated to ensure accuracy. During this process, it is common to determine the flow coefficient of the orifice, which is a dimensionless number indicating the flow capacity of the orifice. The flow coefficient accounts for the size, shape, and other physical characteristics of the orifice plate. Calibration also allows for the calculation of the pressure drop across the orifice, which can be used with the flow coefficient in the Bernoulli equation to measure fluid flow rate. This ensures the instrumentation is operating correctly, as inaccuracies can lead to errors in process control, accounting, and economic decisions in industrial applications.