9. GLOSSARY
Page 149
© 2007 DH Instruments, a Fluke Company
9
9
.
.
G
G
L
L
O
O
S
S
S
S
A
A
R
R
Y
Y
Axxx
A type of Q-RPT with a built-in vacuum reference that is intrinsically absolute (e.g. A10M). In
PPCH-G, Axxx Q-RPTs support absolute and gauge measurement modes.
Absolute Mode
Measurement mode in which the Q-RPT indicates absolute pressure (difference from vacuum).
AutoRange
A function that optimizes PPCH-G measurement and control for a specific, user defined
range of operation.
AutoRanged Range
A PPCH-G range created using the AutoRange function.
AutoTest or ATest
PPCH-G on-board automated testing sequences and their results.
AutoZero or AutoZ
A process by which a Q-RPT and measurement mode is rezeroed (offset) relative to a standard.
Barometer
PPCH-G’s on-board atmospheric pressure measuring sensor. Also referred to as
on-board barometer.
Control Mode
Type of automated pressure control (static, dynamic, monotonic or ramp).
Control Parameters
Parameters affecting pressure control and the
Ready/Not Ready
determination (target,
target limit, hold limit, stability limit, rate limit).
Custom Control
Automated pressure control in which the control parameters are not the default control
parameters.
Default Range (DF)
A Q-RPT or utility sensor’s maximum range that is always available on
[RANGE]
and
cannot be deleted.
Deviation
The deviation of the current pressure from the target pressure control value. Indicated in
MAIN RUN screen when in dynamic control mode.
DUT
Device Under Test. The device or devices pneumatically connected to the PPCH-G
TEST
port that the PPCH-G is being used to test or calibrate.
Dynamic Control
Control mode in which the pressure is constantly adjusted to remain as close as
possible to the target value.
External device or
External Q-RPT
A Q-RPT in an RPM4 external to PPCH-G used by PPCH-G for precise pressure
measurement.
FS
Abbreviation of “full scale”. The full scale value is the maximum pressure or the span of
a measurement range. Limits and specifications are often expressed as % FS.
Gauge Mode
Measurement mode in which the Q-RPT indicates gauge pressure (difference from
atmospheric pressure), but only in the positive direction (above atmosphere).
Head
A difference in height between the PPCH-G reference level and the DUT.
Hold Limit
An automated pressure control parameter. Maximum acceptable difference between the
current pressure and the target pressure value.
IH or IuH
Internal, Hi. The Q-RPT (IH) or utility sensor (IuH) internal to PPCH-G if there is only
one or, if there are two, the one that has the highest full scale default range.
IL
Internal, Lo. Refers to a Q-RPT internal to the PPCH-G that is the lower of the two if
there is a second Q-RPT or utility sensor in the PPCH-G.
Measurement Mode
Whether pressure is being measured relative to absolute zero or vacuum (absolute mode)
or relative to atmospheric pressure (gauge mode).
Monotonic Control Mode
Automated pressure control mode in which pressure is set to a target value and then
controlled at a low rate of change in the same direction as the as the pressure set.
P
offset
The difference between a Q-RPT reading and the AutoZero reference at the time AutoZ
is run. Used by the AutoZ function when Auto Z is ON to compensate Q-RPT readings
for changes in zero over time.
P
std,0
AutoZero reference value. Value indicated by the device against which the Q-RPT is
zeroed by AutoZ.
PA
Pressure adder, used to offset a Q-RPT, utility sensor or barometer to calibrate it.
