GE PACE5000, User Manual

Page: 63 / 98

6 Reference and Specification
K0443 Revision A 6 - 10 [EN] English
6.5 Control Set-up
Vent
Select Vent to reduce the system pressure to near atmospheric pressure. Use this feature to
reduce system pressure to a safe value before disconnecting the UUT. Use vent set-up to
adjust the slew rate of venting.
Note: The vent key can be selected in the control set-up menu or programmed as an on-
screen selection in the status area from the global set-up/ display/status area menu.
Nudge
Sets the incremental resolution of the nudge control for trimming the set-point digits.
Set-point Limits
Defines the limits of pressure that can be entered as a set-point (used for protecting sensitive
UUT).
Slew rate
Sets how the controller achieves a set-point.
Control mode
Selects one of the three modes that follow:
Active Control
In this mode, the controller continuously maintains the set-point, compensating for small
pressure leaks and thermal affects.
Passive Control
In this mode, the user can define a band either side of the set-point, the default band equals
to the instrument’s precision. When the controlled pressure enters this band, the controller
automatically shuts-off. If the measured pressure exits the band, the controller automatically
re-establishes the pressure, without instability, the controlled pressure re-enters the band.
Note: If passive mode is in use with a leak free and thermally stable system then the control
stability contribution can be discounted from the uncertainty calculation.
Zero Gauge Control
The controller switches off once stable at zero gauge and the zero valve opened. Entering a
new set-point causes the zero valve to close and the controller starts to control to the new
set-point.
Max Rate Setpoint step changes to new setpoint
Linear: Controller changing pressure linearly to set-point at a rate set by user.
Rate: Either maximum rate or at a rate (value) set by user.
Overshoot: Fast changing pressure may go beyond set-point.
No overshoot: Changing pressure at an exponential rate but remaining within limits.
Note: This function should be used for UUT that have hysteresis errors.