Fluke RUSKA 7252, Руководство пользователя

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RUSKA 7252
Users Manual
4-20
On permanent absolute instruments, a vacuum pump and vacuum gauge is required to
zero the instrument. The optional vacuum gauge sensor is installed in a port that is
located internally to the Calibrator very near to the RUSKA quartz sensor. When
initiating the zeroing command in the Calibrator, it will cycle the internal valves allowing
the external vacuum pump to pull a hard vacuum on the RUSKA sensor. It is
recommended that the sensor be pulled down to a vacuum of less than 200 mTorr
(preferably less than 100 mTorr) in order to obtain a proper zero. The Calibrator can be
zeroed at higher vacuum levels, however, the uncertainty of vacuum sensors tend to
increase at higher vacuum levels, therefore, the uncertainty in the Calibrator would also
increase if zeroed at higher vacuum levels. Once the vacuum level is stable, the user
enters the vacuum level as indicated by the vacuum gauge and then the zeroing procedure
completes. Refer to Chapter 6, Maintenance, of the manual for more detailed information
regarding the zeroing procedure of the Calibrator.
Menu | Program — Storing A Sequence in Memory
A program can be run on only the one selected channel at a time. Consider an exercise
that requires the Calibrator to start at 30 psi, increase to 50 psi, then decrease to 20 psi.
Test sequences like this may be stored in the Calibrator’s memory as a program.
One benefit of storing a sequence in memory is that the user does not have to command
each pressure separately every time a multipoint test or calibration routine is performed.
Another benefit is that the user can specify a tolerance for each set-point pressure. Once a
tolerance is set, the dwell timer will start counting down instead of waiting until the
pressure is at the exact set-point to start the dwell timer. This gives the user a time
advantage compared to manual mode operation and provides a degree of automation
without the use of an external computer.
Note
The Calibrator can store up to 1,000 program steps that may be divided among a
maximum of 20 named programs.
The Program menu operates only on the current channel. The other channel will be in
measure mode while the program is running.
Preparing to Program
Before entering a test sequence, consider the items discussed below.
Program Name
Valid program names range from one to eight characters in length and can include
numbers, upper case letters, and the / , % , and # symbols. For example, Exer#14 and
%FStest are both valid names.
Configuration
Since a program will depend on the current setup of the Calibrator (the current
configuration is stored with the program) the user should set the units, limits, control
parameters, etc., to the desired values before creating a program.
Number of Set-points
Before entering the sequence, the user should determine the number of upscale and
downscale set-points required to complete the exercise.