FPG8601™/VLPC™ OPERATION AND MAINTENANCE MANUAL
© 2007 DH Instruments, a Fluke Company
Page 58
LABEL
DESCRIPTION
Status
The status of the current point. The field can be considered an exploded view of the
ready/not ready indication of the FPG. Do not confuse this label with the status bar
found at the bottom of the main program window. This text field may contain a
combination status information codes that indicate one or more internal limits have
been exceeded. In most cases, zeroing the FPG will remedy the problem. With the
exception of “R”, any status code forces a “Not Ready” condition in the FPG.
Any value present in the status field with the exception of “R”, forces
a “Not Ready” condition in the FPG ready indicator. In most cases,
re-zeroing the FPG is all that is required to remedy the problem.
A
– The ATM pressure exceeds the stability limit or the value is invalid. When an
A
appears, the FPG pressure is not updated regardless of the output of the load cell
and other FPG sensors. Use the
<ATM>
toolbar function to force the reading of
atmosphere.
L
– The lubrication pressure exceeds the stability limit. This should only be a
momentary indication. If it persists, there may be a leak the system or the supply
pressure to the regulator could be running low.
B
– The load cell has an unstable output or has an invalid reading. This is also
indicated by a red dot next to the
<N>
value on the
<Diagnostics Display>
. Since
this value represents noise levels beyond the resolution of the FPG, this indicator
does not cause a “Not Ready” condition when present.
T
– The mounting post or lubricating volume temperatures have changed beyond
the tare limit (see Section 6.6.4.3), the relative difference between the mounting
post and lubricating volume temperatures differ beyond the acceptable limit, or the
rate of change of any temperature indicator exceeds the re-zero limit. The system
should always be re-zeroed if this occurs.
t
– At least one active DUT is out of tolerance relative to the FPG (see Section 6.8.2.4).
R
– Indicates the FPG pressure is not ready based on the current stability and hold
criterion or other status indicators (see Section 3.6).
H
- The humidity value has changed beyond the humidity tare limit or the rate of
change of humidity exceeds the specified humidity rate (see Section 6.6.4.4).
E
- An error exists in the FPG calculation or output of one of its internal sensors.
Calculation errors occur when some of the variables used in calculating the FPG
pressure contain values that generate a math error. When this occurs, no final FPG
pressure value is calculated.
I
– One or more of the FPG calculation components is invalid. When this occurs,
the FPG pressure is not calculated.
P
– The lubrication pressure has changed from it’s zero value more than the re-tare
limit. The system should be re-zeroed when this occurs.
Status
(continued)
V
- The FPG is in absolute mode and the vacuum reference pressure is unstable.
This indication should be momentary. If it persists, there may be a leak on the
reference port, or the vacuum reference stability criterion is too restrictive (see
Section 6.6.4.2).
%RH
Instantaneous lubricating volume humidity.
P Head
The effective head correction in the active FPG pressure unit. Use
[Config]
,
[Settings]
to change the head height value (see Section 6.6.1).
Hi Trans
P(DUT)/P(FPG)
Thermal transpiration correction ratio based on the absolute pressure in the upper
chamber of the FPG. The ratio is the effective DUT pressure divided by the
absolute FPG pressure in the upper mounting post.
Lo Trans
P(DUT)/P(FPG)
Thermal transpiration correction ratio based on the absolute pressure in the lower
chamber of the FPG. The ratio is the effective low side DUT pressure divided by the
absolute FPG pressure in the lower mounting post.
