Pump Test Lab Metering and Measurement
Let’s discuss commonly measured values for a pump performance test, the associated metering equipment, and the application of those measured values on a pump performance report.
Input Power
Input power is most commonly derived from an electric motor (although other sources such as internal combustion engines may also be utilized, we will not be discussing these today). ETL labs may utilize a variety of calibrated electrical measurement devices for capturing input power from submersible motors, but may use a calibrated torque meter for other motor types.
Speed
Motor speed is ideally measured with a torque meter, however motor speed can be approximated from power/frequency measurements and motor nameplate data.
Head
Head is derived from measurements taken during test operation and static measurements of the pump lab configuration. Calibrated pressure transducers are utilized for capturing pressure head. ETL pump labs will take into consideration (where applicable) velocity head, pressure head, friction head and elevation head, when calculating TDH “Total Dynamic Head”.
Flow
Flow rate is measured with inductive flow meters in the discharge piping. Careful consideration is given for spacing both before and after the meter to allow sufficient stabilization distance.
OPTIONAL MEASUREMENTS
- Vibration (multiple sensors may be integrated)
- Fluid temperature, density, viscosity
- Ambient temperature