DH Instruments PPC2 AF - Turning-Off Custom Control Parameters; Head

PPC2 AF OPERATION AND MAINTENANCE MANUAL
© 1998 DH Instruments, Inc. Page 34
 OPERATION
To make custom control parameter settings, press the CUSTOM CONTROL key from the
main run screen. The display is:
1. Entry field for setting the desired hold limit. Recalls the
default hold limit or the last custom hold limit set for the
currently active range.
2. Current control mode (S for static, D for dynamic).
3. Current reference transducer (H for high, L for Lo) and range
(1, 2 or 3).
Set hold limit
± 0.05 psi D H3
Enter the desired hold limit. The next display is:
1. Entry field for setting the desired stability limit. Recalls the
default stability limit or the last custom stability limit for the
currently active range.
2. Current control mode (S for static, D for dynamic).
3. Current reference transducer (H for high, L for Lo) and range
(1, 2 or 3).
14.104 psi a H3
ZSTD: 14.102
Enter the desired stability limit. The display returns to the main run screen with the custom
control parameters active.
Custom control parameters are range and control mode specific. Changes made in one
range and control mode are stored for that range and control mode and will be recalled
when that range and control mode is returned to. Changes made in one range and control
mode do not affect any other range and control mode.
When custom control parameters are active, a C is appended to the control mode
indicating character (S for static, D for dynamic) in the middle of the bottom line of the
main run screen.
3.2.6.1 TURNING-OFF CUSTOM CONTROL PARAMETERS
To return to default pressure control parameters for the active range and control
mode, select the control mode using the CONTROL function (see Section 3.2.3).
3.2.7 HEAD
 PURPOSE
To cause a pressure value representing a difference in height to be added to the pressure
measured by the PPC2 AF reference pressure transducer and to specify the applicable height
and test gas.
 PRINCIPLE
PPC2 AF's reference pressure transducers measure gauge or absolute pressure at the height
of the rear panel TEST port. Frequently, when performing a calibration or test, the device or
system under test is at a different height than the PPC2 AF’s TEST port. This difference in
height, frequently called "head", can cause a significant difference between the pressure
measured by the PPC2 AF at its TEST port height and the pressure actually applied to the
device under test at a different height. In this case, it is useful to make a head correction to