DH Instruments PG7000, Руководство по эксплуатации и обслуживанию

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3. GENERAL OPERATION
Page 91 © 1998-2008 DH Instruments, a Fluke Company
The display is a modified version of the 1
st
system run screen to indicate the piston rotation is
being decelerated while showing rotation rate and position:
1. Current piston rotation rate.
2. Current rate of piston vertical displacement.
3. Current piston position.
48 rpm DECELERATING
+ 2.05 mm 0.1/min
To interrupt the piston rotation braking routine, press [ESCAPE] .
Most PG7000 platforms produced before 2006 use a solenoid based rotation actuation
system. The system is protected against overloading. If the duty cycle becomes excessive,
motorized rotation cuts OFF and remains off for a 25 second delay. During the cutoff time, [
]
has no effect.
The motorized rotation system can be set to operate automatically based on current
piston position and rotation rate. See Section 3.9.8 for information.
In PG7000 high line differential mode (see Section 3.9.4.2), pressing [ ] on the reference
PG7102 engages motorized rotation (if present) on both the reference and tare PG7000s.
3.10 [SETUP] MENU
PURPOSE
To select, view and edit the SETUP files that determine the source of the values that PG7000 uses in its
calculation of defined pressure and as criteria for
Ready/Not Ready condition determination.
PRINCIPLE
PG7000 piston gauges perform continuous, real time calculations of the pressure defined by the floating
piston under current conditions (see Section 7.2 for the details on the calculations applied). The
calculations are used to determine the defined pressure displayed in the MAIN run screen, and to arrive
at the mass to load value when a target pressure is entered in
pressure to mass mode.
The equations that PG7000 uses to calculate pressure include many instrument and ambient variables.
PG7000 allows the source of the value used for each variable to be defined. For example, the value
of barometric pressure used to calculate current air density and to add to gauge pressure to define
absolute pressure in
absolute by atmosphere mode could come either from PG7000’s internal sensor,
an external barometer connected to PG7000’s COM2, a user entered value or be set to standard
atmospheric pressure. The PG7000 SETUP function allows the source (and in some cases the value) of
the variables used in the pressure equations to be specified. In order to allow various combinations of
sources and/or values to be setup and recalled, SETUP files can be created, stored, edited and recalled.
The SETUP files also include certain variables used to determine PG7000
Ready/Not Ready status.
Table 19 identifies the variables included in the SETUP file, the factory source setting for each variable
and the default value for each variable.