Pressure Effects
- Elevated pressures (above atmosphere) allow for greater capacity for a given flowmeter
- To determine the actual flowrate (at the elevated pressure), the following formula is used:
- All pressures are in absolute, not gauge
Temperature Effects
- Elevated temperatures (above standard atmospheric temperature) decrease maximum flow rate for a given flow body
- To determine the actual flow rate, the following formula is used:
- All temperatures are in absolute
Pressure Correction Example
- Our flowmeters are calibrated at a standard pressure of 14.696 PSIA (which is equivalent to 0 PSIG)
- If a customer is operating the meter at 20 PSIG, what will the effect be on the flow reading?
- The actual flowrate will be higher thanthat indicated by the flowmeter
- How much higher will it be?
Actual flowrate = Indicated Flowrate x 1.5365
Temperature Correction Example
- Our flowmeters are calibrated at a standard temperature of 20 °C or 68 °F
- If a customer is using the meter at 30 °C, what will the effect be on the flow reading?
- The actual flowrate will be lower thanthat indicated by the flowmeter
- How much lower will it be?
Actual Flowrate = Indicated Flowrate x .9834