7. 10BAPPENDIX
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© 1998-2008 DH Instruments, a Fluke Company
7.3
GLOSSARY
Absolute
As in absolute pressure. Pressure expressed relative to vacuum.
Absolute by vacuum,
avac
Absolute pressure determined by defining pressure relative to vacuum in an evacuated bell jar
(PG7601 only).
Absolute by
atmosphere, aatm
Absolute pressure determined by adding atmospheric pressure to gauge pressure.
Adder
A value added to internal sensor readings to offset the readings (pressure adder, temperature
adder, humidity adder, vacuum adder) for calibration adjustment.
Ae
Piston-cylinder effective area.
AMH
Optional automated mass handling system.
ATM Head
Pressure head correction to the barometer measurement to take into consideration the
difference between the actual barometer level and the PG7000 reference level.
Crossfloat
Process of comparison of two piston cylinders in which they are connected together under
pressure and the mass of one is adjusted so that both pistons float together at a common
pressure. Used to set the line pressure in high line differential measurement mode.
Differential
As in differential pressure. Pressure expressed relative to atmospheric or another static
pressure determined by subtracting the static pressure from absolute by vacuum (differential
measurement mode).
DUT (Device Under
Test)
The device being tested or calibrated.
DUT Head
Fluid head correction to the pressure defined by PG7000 to predict the pressure at the level of
the DUT, which may be different from the PG7000 reference level.
FS (Full Scale)
The full scale value is the maximum value or the span of a measurement range. Limits and
specifications are often expressed as % FS.
g, gl
Acceleration due to gravity (g). Acceleration due to gravity at location of use (gl).
Gauge
As in gauge pressure. Pressure expressed relative to atmospheric pressure.
He
Helium gas.
Head
Fluid head, a pressure difference due to a difference in height. See also ATM head, DUT head
and PISTON head.
High Line Differential
As in high line differential pressure measurement mode. Pressure expressed relative to a line
pressure greater than atmospheric pressure. Defined by using two piston gauges.
HSTOP, LSTOP
High stop and low stop, piston maximum end of stroke positions.
InHg
Pressure unit of measure, inches of mercury.
InWa
Pressure unit of measure, inches of water.
kcm
2
Pressure unit of measure, kilogram per centimeter square.
Line Pressure
Pressure on the low side in high line differential pressure measurement mode. Pressure relative to
which the differential pressure is defined.
Measurement Mode
Mode in which PG7000 is defining pressures. These include gauge (pressure relative to
atmospheric pressure), absolute by atmosphere (pressure relative to vacuum determined by
adding atmospheric pressure to gauge pressure), absolute by vacuum (PG7601 only) (pressure
relative to absolute vacuum determined by establishing a vacuum around the mass load),
differential (PG7601 only) (pressure relative to atmospheric or another static pressure
determined by subtracting the static pressure from absolute by vacuum).
MS (Mass Set)
A group of masses composed for use with a PG7000 piston gauge.
Mass Bell
The sleeve loaded onto the piston to carry other masses.
Mass Entry Mode
(mass to pressure)
Operating mode in which the user enters the mass loaded on the piston and the PG7000
calculates the defined pressure. See also Pressure Entry Mode.
Medium, pressurized
The pressurized fluid.
Multiplier
A value by which internal sensor readings are multiplied to change their slope (pressure multiplier,
temperature multiplier, humidity multiplier, vacuum multiplier) for calibration adjustment.
N2
Nitrogen gas.
Nominal Mass
The mass loaded on the piston in terms of the nominal values written on the individual masses.
See also True Mass.
Normal
A conventional or standard value.
