Galvanic Applied Sciences 943-TGX, Operation Manual

Page: 52 / 110

Revision 4 52 August 02, 2019
•
Back Purge - The
Back Purge
button is used to indicate that zero gas (purge gas)
should be allowed to flow through the system. The Sample/Purge indicator will be
flashing red and the words Back Purge Sample will be indicated when zero gas is
flowing through the system. When
Back Purge
is selected, the analyzer sampling
system is continuously back purged with zero gas. This is useful as a precursor to
maintenance activities or when long term purging is required.
• Manual Zero - The Manual Zero button is used to initiate a zero sequence.
5.2.1.3 R elay Indicator Fields
The Relay Indicators show the state of the analyzer outputs:
a) Status
Normal
(Green) status indicates that the system is working properly.
Fault
(Red) status indicates that the computer has detected an error in one of the critical
analyzer functions. The Status indicator and alarm relay are placed in a fault state. The
analyzer will go into backpurge mode when a fault is detected. An occurrence of a fault
status automatically forces the
Control
to
Manual
.
b) Service
Normal
(Green) status indicates that service is not required
Warning (Red Flashing) indicates that the computer has detected that one of the
parameters for a warning condition is out of range. This indicates that service is
requested but not required immediately. The analyzer continues to function normally,
producing usable outputs.
c) Mode
Run
(Green) status indicates that the system is in
Run
mode
Calibrate
(Red Flashing) indicates that a zero calibrate sequence is in progress. At the
end of the calibration sequence the
Mode indicator
returns to
Run
. A manually initiated
Zero operation also causes a
Calibrate
mode. The mode alarm relay contacts are
changed in conjunction with the indicator. An occurrence of the Calibrate mode
automatically forces the ‘Control’ to Manual.
d) Control
Auto
(Green) indicates that the analyzer output signals are deemed to be a valid
measurement of the process gas stream and may be used for control purposes if desired.
Manual (Red Flashing) indicates that the analyzer output signals should be assumed to
be invalid (with respect to process stream measurement) and should not be used for
control purposes. The analyzer automatically forces the
Control
indicator to
Manual
in
case of any analyzer fault, a calibration sequence in progress (either manual or auto), or
a user initiated ‘Off Line’ request.