Technical note | Static Check-Calibration of a Dynamic Pressure Measurement System: Serial Numbers DPM1201 and DPM1203

Abstract

A static check-calibration of a Turbulent Flow Instrumentation (TFI) Dynamic Pressure Measurement System (DPMS), consisting of two modules (serial numbers DPM1201 and DPM1203) with 32 pressure transducers each, is performed and documented in this report. It is estimated that the best-case uncertainty in pressure measurements using the DPMS is ±10.42 Pa at 95% confidence with a coverage factor of 2, occurring on channel 38. The worst-case uncertainty is estimated to be ±13.26 Pa at 95% confidence with a coverage factor of 2, occurring on channel 29. The mean uncertainty over all 64 DPMS transducers is calculated to be ±10.73 Pa at 95% confidence with a coverage factor of 2, with a standard deviation in the mean uncertainty of ±0.414 Pa.

Executive Summary

A static check-calibration of a Turbulent Flow Instrumentation (TFI) Dynamic Pressure Measurement System (DPMS), consisting of two modules (serial numbers DPM1201 and DPM1203) with 32 pressure transducers each, is performed and documented in this report. A previous static calibration was supplied by TFI in 2012 for a Full Scale (FS) calibration range of 4.5 kPa, but the precise uncertainty associated with this calibration is still unknown.

Here, the check-calibration results show that the best-case expanded uncertainty in pressure measurements using the DPMS is ±10.42 Pa at 95% confidence with a coverage factor of 2, occurring on channel 38. The worst-case expanded uncertainty is estimated to be ±13.26 Pa at 95% confidence with a coverage factor of 2, occurring on channel 29. The mean uncertainty over all 64 DPMS transducers is calculated to be ±10.73 Pa at 95% confidence with a coverage factor of 2, with a standard deviation in the mean uncertainty of ±0.414 Pa.

The worst-case expanded uncertainty estimation in this report is found to be less than the stated accuracy of the DPMS transducers of ±0.3% FS, or ±13.5 Pa at a FS calibration range of 4.5 kPa. Therefore, no adjustments were made to the current DPMS calibration. Also, the standard deviation of the mean uncertainty over all 64 DPMS transducers is sufficiently low, such that the mean uncertainty of ±10.73 Pa could be used to represent the uncertainty in DPMS pressure measurements.