DH Instruments PPCK PLUS, Operation And Maintenance Manual

Page: 139 / 150

PPCK+™ Operation and Maintenance Manual
Page 131
©2001 DH Instruments, Inc .
Table 18. Troubleshooting Guide (Continued)
SYMPTOM POSSIBLE CAUSE SOLUTION
Disagreement between
measurements made by different
ranges at the same pressure is
not zero but an autozero routine
was just executed. Readings by different ranges at
the same pressure in absolute
measurement mode can
disagree even after a valid
autozero due to ZNATERR. Check that ZOFFSET value is in
tolerance and verify value of
ZNATERR (3.4.1, 1.2.2.1, 5.2.6).
Will not accept command to set
pressure. Target exceeds UL and/or
current range. Check UL (3.2.4) and range
(3.2.1).
Poor pressure control. High pressure supply is not of the
correct value or excessively
unstable. Connect correct pressure supply,
regulate pressure supply, install
a pressure accumulator if the
action of a booster is causing the
pressure supply to fluctuate
excessively (2.3.4).
Poor pressure control in dynamic
control mode characterized by
"hunting" around target. Thermal Pressure Control (TPC)
has incorrectly calculated test
volume. Run Config routine (5.5, 3.1.2.3).
Poor pressure control
characterized by control not
“locking on” target pressure. Control mode is set to static
rather than dynamic. Behavior is
normal. Use [CONTROL] to set control
mode to dynamic (3.1.2.3, 3.2.3).
Poor pressure control
characterized by
Ready condition
occurring when the pressure is
not at the target value.
Control mode is set to static
rather than dynamic or control is
not active. Behavior is normal.
Use [CONTROL] to set control
mode to dynamic; use
[ENTER/SET P] to active
pressure control (3.1.2.3, 3.2.3,
3.2.10).
Poor pressure control when
setting zero absolute pressure
characterized by
Ready condition
occurring when vented at
atmospheric pressure.
Pressure setting commands for
zero absolute are interpreted as
a VENT command because
PPCK+ cannot set pressures
under atmosphere. Operation is normal (3.2.10.1).
Poor pressure control
characterized by excessive
overshooting and/or
undershooting, inability to lock-on
target. There is a restriction in the test
connection between the PPCK+
and the test. Remove the restriction to allow
free flow between the PPCK+
and the test.