Fluke RUSKA 7252, User Manual

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RUSKA 7252
Users Manual
2-4
Pneumatics Module
The Calibrator's Pneumatics Module varies depending on whether the Calibrator is a
Gauge mode, Absolute mode, or a Simulated Absolute mode instrument. Gauge mode
Calibrator's reference their measurements to atmospheric pressure, whereas Absolute
mode Calibrator measurements are made with respect to sealed vacuum. A Simulated
Absolute mode Calibrator has a barometric sensor in addition to a gauge Bourdon tube
sensor. The Calibrator adds the barometric reading to the Bourdon tube reading to obtain
a Simulated Absolute value. It can operate as a Gauge mode instrument if the user selects
to not add the reference pressure.
The valves, filters, and transducers that make up the pneumatics module of a Gauge mode
(or Simulated Absolute) Calibrator are shown in Figure 2-2. The Schematics for the
Absolute mode Calibrator is shown in Figure 2-3.
In the sections that follow, the Zero, Isolation, Apply and Release valves are all 24-volt,
DC solenoid valves that are either open or closed depending on the Calibrator’s
operational mode. Their behavior is summarized in Table 2-2.
PRIMARY SENSOR
INNER LOOP CONTROL SENSOR
SUPPLY
PRESSURE PORT
EXHAUST
PORT
RELEASE APPLY
BAROMETRIC
REFERENCE
SENSOR
(SIMULATED
ABSOLUTE
OPTION)
ISOLATION
(< 1000 PSI FS)
ZERO
TEST
PORT
REFERENCE
PORT
Control Section
V
VACUUM
SENSOR
Option
glb03.eps
Figure 2-2. RUSKA 7252 Calibrator Gauge Pneumatics Diagram 0.36 to 2500 psig (2.5 kPa to 17.2
MPa) Full Scale Ranges
Note
This diagram depicts only one of the two RUSKA 7252 channels.