-
45
-
Sampling Fault
When sampling does not end normally, "FAULT"
is displayed on the 2nd line, and the cause of the
fault stop is displayed on the 3rd line. In the
example on the right, "Pressure Drop" (pressure
loss fault) is displayed.
When a fault stop has occurred, data up to the
point when the fault stop occurred is recorded.
Note, however, that when a power voltage fault
has caused the stop, all data may be lost
depending on the timer setting.
(
For details, see P46.)
List of Fault Stop Items
Displayed
Message
Fault Stop Cause
Pressure Drop
Pressure loss fault:
A pressure loss of 40 kPa or more continued
for 30 seconds.
Ambient Temp.
Ambient temperature fault: An ambient temperature of 45
°
C or higher
continued for 30 seconds.
Flow Rate
Suction flow rate fault:
An error of
±
20 % or more of the set value
continued for one minute.
Power Low Vol.
Power voltage fault:
A power failure occurred or a BU-24B/BU-24L
(sold separately) voltage of 21 V or less
continued for 30 seconds.
7.6 Flow Rate
Instantaneous Flow Rate
For the suction flow rate, the suction pump is controlled and constant flow rate is maintained so
that the instantaneous flow rate display matches the preset flow rate. The instantaneous flow rate
is calculated by the following flow rate formula, and is indicated according to the selected flow
rate unit. The volume flow rate unit (Standard VF) after conversion to 25
°
C and 1 atmosphere is
indicated as the default instantaneous flow rate.
Qa = Qc
×
1013.25/Pa
×
(273.15 + ta)/(273.15 + tc)
Qs = Qc
×
(273.15 + ts)/(273.15 + tc)
where,
Qc: Volume flow rate after conversion to a standard state at flow rate calibration (L/min)
Qa: Actual volume flow rate (Actual VF) (L/min)
Qs: Volume flow rate after conversion to a standard state (Standard VF) (L/min)
Pa: Ambient pressure (hPa),
ta: Ambient temperature (
°
C)
ts: Standard temperature (
°
C), tc: Standard temperature (
°
C) that was set at flow rate
calibration
Total Flow Rate
The total flow rate is calculated by adding the instantaneous flow rate at 1-second intervals in
units matched to the selected total flow rate unit. The default total flow rate is indicated by adding
the instantaneous flow rate of the volume flow rate unit (Standard VF) after conversion of the
total flow rate to 25
°
C and 1 atmosphere.
F i n i s h e d
F A U L T
P r e s s u r e
D
r o p
P r e s s
[ D O W N ]
t o
d i s p l a y
" T o
t a l
V o l u m e " .
M e m o r y
T i m e
R e m a i n i n g : 1 2 9 h r s
