Galvanic Applied Sciences 943-TGS, Operation Manual

Page: 53 / 112

Revision 1 53 6/27/2017
5.2.1.2 Status and Control
• Online Status - A green indicator and the word Online is presented if the instrument is
online. A flashing red indicator and the word
Offline
is presented if the unit is offline.
The state of the Online/Offline button does not affect the operation of the analyzer. The
ability to remotely signal plant operations using the relay output of the Control indicator (in
conjunction with the
Online/Offline
button) has been incorporated as a convenience to the
user. The Online/Offline function essentially provides a method of signaling to the operator
that the analyzer data is invalid (i.e. the system is undergoing maintenance or servicing).
When returning the analyzer to Online status, the relay indicator for Control (see below) will
return to the Auto state only if no fault or calibration conditions exist.
• Sample/Backpurge - A green indicator and the word Sample is presented if sample is
being monitored. A flashing red indicator and the words Back Purge is presented if zero
gas is being monitored. The option of sample or back purge is effected by the buttons
directly below the Sample/Backpurge line. The default condition of the analyzer is to have
zero gas flowing through the cell.
•
Manual Zero - The
Manual Zero
button starts the zero calibration sequence of the analyzer
which incorporates the checking and adjusting of the instrument zero (baseline). No span
correction is required under normal circumstances on an installed analyzer. The calibration
sequence is identical whether trigger manually or automatically.
When triggered, the calibration sequence proceeds in the following order:
a) The Mode relay outputs changes to Calibrate and the Control relay changes to Manual .
b) The zero gas solenoid is de-energized and zero gas is introduced into the measurement
cell. The zero gas is allowed to purge the measurement cell for the number of seconds
specified by the Zero Purge Time parameter on the Parameters page (Section 5.3.1).
c) At the conclusion of the zero purge interval, the computer averages the last ten (10)
spectrometer scans and determines a new reference scan vector (captures the new zero
value). At this time the zero gas solenoid is de-energized to allow sample gas to flood
the cell.
d) The analyzer waits for the number of seconds specified by
the Zero Hold Interval
parameter on the Parameters page (Section 5.3.1).
e) During this period, process sample gas flows into the measurement cell and the
displayed concentration values will rise from zero to the measured values. The Zero Hold
Interval allows the analyzer concentration outputs to stabilize at on-line values before the
outputs are updated.
f) The Mode relay changes to Run and the Control relay output changes to Normal at the
expiration of the Zero Hold Interval (barring a pre-existing fault condition).
•
Sample - The
Sample
button is used to indicate that the sample gas should be allowed
to flow through the system. The Sample/Purge indicator will be green and the word
Sample will be indicated when sample is flowing through the system.