Pressure Ready/Not Ready; Parallel Measurement Mode - Fluke RPM4-AD Operation And Maintenance Manual

RPM4-AD™ OPERATION AND MAINTENANCE MANUAL
To measure airspeed and altitude using this mode, use [RANGE] (see Section
3.3.1.2) to select the <Hi> Q-RPT or the <airspeed & altitude> shortcut. If the
shortcut is not used, once the Q-RPT has been selected, use [MODE] (see
Section 3.3.3) to set absolute and differential measurement mode and [UNIT]
(see Section 3.3.2) to set the desired airspeed unit. Use [DISPLAY], <4RPT> to
change the altitude unit if desired (see Section 3.3.6.4).
3.2.4

PRESSURE READY/NOT READY

There is a Ready/Not Ready indication LED on the RPM4-AD front panel. This indication is
intended to provide the user with an objective indication of when a stable pressure has been
achieved. Ready is indicated when the current stability (rate of change) of pressure is less
than the stability limit. The user can set the stability limit (see Section 3.4.3). The ready
indication is often used when comparing the RPM4-AD and a test device to indicate when a
valid reading can be made.
The Ready/Not Ready indication always applies to the active Q-RPT, whose pressure
measurement is displayed on the top line of the RPM4-AD display.
The Ready/Not Ready LED indications are:
<Green > Pressure Ready
<Red> Pressure Not Ready
In differential measurement mode (see Section 3.2.6), the LED Ready/Not Ready
indication applies to the differential pressures.
In parallel measurement mode (see Section 3.2.5), the LED Ready/Not Ready indication
applies to the average pressure read by the <HL> Q-RPT.
The Ready/Not Ready LED indications are:
<Green > Pressure Ready
<Red> Pressure Not Ready
The default stability limit criteria for the Ready/Not Ready determination is:
Absolute measurement mode: ± 0.001875% of absolute mode span
Gauge measurement mode: ± 0.005% of gauge mode span
3.2.5 PARALLEL MEASUREMENT MODE (//M
A160K/A160K ONLY)
RPM4-AD A160K/A160K can be set to operate in parallel measurement mode. Parallel
measurement mode is used to measure altitude with the lowest uncertainty (see Section 3.2.3.1).
Parallel measurement mode is intended to improve measurement reliability and reduce measurement
uncertainty by using the measurements of two Q-RPTs together. In parallel measurement
mode, the measured pressure is the average of the readings of the two Q-RPTs.
Parallel measurement mode is considered a Q-RPT designated <HL> (combination of Hi and
Lo). The HL Q-RPT can be selected using the [RANGE] (see Section 3.3.1.1) key and
operated with all the features of a Hi or Lo Q-RPT.
In parallel measurement mode the active TEST port depends upon the measurement mode. In
absolute measurement mode the TEST(Ps) port is active and the TEST(Pt) port is shutoff. In
gauge measurement mode the TEST(Pt) port is active and the TEST(Ps) port is shutoff.
© 2005-2007 DH Instruments, a Fluke Company
The pressure stability is within the stability limit.
The pressure stability is NOT within the stability limit.
The pressure stability is within the stability limit.
The pressure stability is NOT within the stability limit.
Page 20
) (RPM4-AD
T M