2 pressure measurement specifications, 1 quartz reference pressure transducers (q-rpt), 2 on-board barometer – Fluke HPMS User Manual
Page 13: Pressure measurement specifications, Quartz reference pressure transducers (q-rpt), On-board barometer
1. INTRODUCTION
Page 3
© 2007 DH Instruments, a Fluke Company
1.2.2
PRESSURE MEASUREMENT SPECIFICATIONS
1.2.2.1
QUARTZ REFERENCE PRESSURE TRANSDUCERS (Q-RPT)
RPM4 A70M/A20M is configured with two quartz reference pressure transducers
(Q-RPT) modules to measure pressure.
The Q-RPTs can measure absolute and gauge pressure. Gauge pressure is
defined by offsetting atmospheric pressure and applying dynamic compensation
for atmospheric changes using the on-board barometer (see Section 3.2.2).
Warm Up Time
30 minute temperature stabilization recommended from
cold power up.
Compensated Temperature Range
5 to 35 °C
Operating Temperature Range
8 to 28 °C
A20M Q-RPT
A70M-QRPT
Maximum Range
3 000 psi (20 MPa)
10 000 psi (70 MPa)
Resolution
user adjustable to 1 ppm of Q-RPT maximum or 10 ppm
of active AutoRange, whichever is larger,
Precision
1
± 0.0175 % of reading, or
0.13 psi, whichever
is larger
± 0.0175 % of reading, or
0.44 psi, whichever
is larger
Predicted Stability
2
± 0.004 of reading
Measurement Uncertainty
3
± 0.02 % of reading, or
0.15 psi, whichever
is larger
± 0.02 % of reading, or
0.5 psi whichever
is larger
1. Combined linearity, hysteresis, repeatability.
2. Predicted Q-RPT measurement stability limit (k=2) over one year assuming regular use of AutoZero function.
As stability
can only be predicted and varies from Q-RPT to Q-RPT, stability for a specific Q-RPT should be established from
experience.
3. Maximum deviation of the Q-RPT indication from the true value of applied pressure including precision, predicted one
year stability, temperature effect and calibration uncertainty (assumes calibration reference uncertainty of ±0.005% of
reading), combined and expanded (k=2) following the ISO “Guide to the Expression of Uncertainty in Measurement.”.
1.2.2.2
ON-BOARD BAROMETER
The measurement uncertainty of the on-board barometer is not significant to
RPM4 Q-RPT measurement uncertainty. It is used only to measure small, short
term changes in atmospheric pressure to provide dynamic compensation of the
Q-RPT’s atmospheric pressure offset when in gauge pressure measurement
mode (see Section 3.2.2)
Sensor Technology:
Micro-machined silicon
Warm Up Time:
None required
Resolution:
0.1 Pa (0.000015 psi)