Fluke Calibration RUSKA 7615, User Manual

Page: 33 / 64

Local Operation
Controlling Pressure
4
4-5
Using Head Pressure Correction
The term head height refers to the vertical distance between the sensing element in the
device under test and the Calibrator’s sensor. Once the user inputs the head height and
specific gravity of fluid used the Calibrator automatically corrects for head pressure.
1.
Determine the PRESSURE REFERENCE line on the Calibrator’s front panel. This
line indicates the vertical location of the Calibrator’s sensor.
2. Determine the vertical distance between the PRESSURE REFERENCE line and the
sensing element in the device under test.
3. The head height is set from the Setup User menu. From the Main Menu (press PREV
until the Main Menu appears) press Menu [F6] | Setup [F2] | User [F2].
4. Press Length [F1] to select either inches (in) or millimeters (mm) for the head height
entry. The select units will appear on the Head line to the right of the number.
5. Highlight specific gravity and enter the specific gravity of the fluid used in the
system.
6. Press the up or down arrow keys to highlight the label Head Height.
7. Use the numeric keypad to enter the height. Use a negative value if the DUT is below
the Calibrator.
8. Press ENTER to accept the entry.
9. Press PREV to exit the menu. Press CANCEL to return all edited fields to their
original values.
Set Tare Mode
The tare mode provides instant zeroing at the push of a button. The tare mode also allows
switching from absolute to gage pressure for a short term tests.
1.
The tare mode is set from the Tare menu. From the Main Menu (press PREV until the
Main Menu appears) press MENU | MODE | TARE.
2. In this menu press TARE [F4] to toggle between Tare mode and Absolute mode.
Tare value is displayed in the highlighted area.
Controlling Pressure
The 7615 is designed to control pressure to a commanded set-point. From the main menu,
it is first recommended to enter a desired set-point (See Chapter 4, Setting the Pressure
Set Point). Then select the CONTROL key, and you will be prompted to hit ENTER to
continue. The system will then control the pressure to the commanded pressure value.
Control Modes
The standard control modes of operation are Normal and Cycle. To select the control
mode, select the MENU/MODE key. To enter the cycle Mode, hit the [F4] key
labeled cycle.
Normal Mode
This control mode suits high performance sensor calibration where overshoot is to be
minimized. The control parameters and slew rates are optimized to give the fastest rate of
change that is commensurate with minimal overshoot. At the end of the calibration cycle,
the oil can be fast dumped to the reservoir or stepped down under control.