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Software
Options
To access the Options screen, choose “Options” from the “Edit” menu.
“Pressure Minimum Deadband” -
During testing, the pressure inside the
test cell is likely to increase due to thermal expansion. When the pressure
rises too high, the software bleeds off the excess. If the pressure drops
too low, the software increases the pressure. The software calculates the
threshold by adding 3% of the setpoint to the value in the “Minimum Pressure
Deadband” field.
For example, assume the pressure setpoint is 10,000 PSI and the “Pressure
Minimum Deadband” is set to 100. The threshold in this scenario is 400
(10,000 × .03 + 100). Therefore, if the pressure increases to 10,400 PSI, the
software will open the pressure release valve and bleed off the excess. And, if
the pressure drops below the setpoint (10,000 PSI), the software will engage
the pump to increase the pressure.
“Low Pressure Limit” -
This field determines when a test will be aborted
due to low pressure. If the pressure drops more than the value in this field,
the unit will automatically turn off the pump and the heater to avoid damaging
the equipment. The value in this field is relative to the operating pressure.
“One Heater / Two Heaters” -
The heater switch adjusts the heater PID
controller to change whether the unit is using one or two heaters to set the
test temperature. Switching from two heaters to one can be useful at lower
temperatures (generally less than 325°F / 163°C) because it provides more
control over the temperature range. This function should be used with the
“Heaters” switch on the front control panel of the unit.
“Precision Stop Mode” -
The HTHP Viscometer measures shear stress
by reading the position of the magnets that turn the rotor. When the rotor
stops, if the magnets are not centered at their origin position, the shear
stress reading in the ORCADA
®
software will not read 0. The precision stop
addresses this by stopping the rotor with the magnets centered in their origin
positions. Instead of an immediate stop, the rotor is first slowed so that it can
be more accurately stopped at the origin.
“None” -
Never perform a precision stop.
“Gel Only” -
Only perform a precision stop before a gel test.
“Always” -
Perform a precision stop every time the rotor is stopped. This
setting is recommended.
“Precision Stop RPM” -
This field sets the speed of the rotor during a
precision stop. A lower value here will produce more accurate results, but the
rotor will take more time to come to a complete stop. A higher number will
stop faster, but will provide less accurate results. 3 RPM is recommended.
