2101510MNA H | NGC820 0 AN D PGC 1000 US ER MA NUA L |
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10.12.3 Backward clock change crossing a log period boundary
This forces a log period entry for part of the log period that has accumulated since the last log period
entry. This is the same as for a forward clock change crossing an hourly boundary. The analyzer
advances to a new day’s data flow record and maintains the balance of the day’s data in a new record.
Example: If the present time is 5:05 p.m. and the clock is changed to 4:55 p.m. of the same day, the
log period record entry reflects only a 5 minute average accumulation (5:00 to 5:05). Then a new flow
record is written and this log period is based on a 5 minute accumulation (4:55 to 5:00).
IMPORTANT NOTE:
A backward clock change uses two (2) daily records to maintain data
integrity. This assures that previously recorded data is not overwritten.
If it is necessary to make small backward time changes, less than one (1) hour, the user should
wait until the current hour has progressed far enough to make a change that does not cross an
hour boundary.
10.13 Replace calibration or carrier gas cylinder(s)
When calibration or carrier gas cylinder(s) require replacement, use the following instructions.
To replace a cylinder:
1.
On the Analyzer Operation screen, click
Hold
under Next Mode. When the device completes the
current cycle and enters hold, continue to the next step.
2.
Turn off the calibration and/or carrier gas at the cylinder.
3.
Remove the regulator from the cylinder.
4.
Exchange the used cylinder with the full cylinder.
5.
Re-install the regulator into the cylinder. Verify that the pressure regulator is set correctly to
either 15 PSIG for calibration gas or 90 PSIG for carrier gas. Open the shut-off valve on the
regulator.
6.
At the feed-through assembly, loosen the nut and ferrule from the corresponding inlet, allowing
air to purge from the line.
DANGER – Serious damage to health / risk to life
. Be sure to follow the requirements
of the national and local codes when performing this purge.
7.
Re-insert the ferrule and nut into the correct inlet and tighten.
8.
Leak test connections at the cylinder regulator and feed-through assembly.
9.
In PCCU, with the device still in hold, run two single cycles. Inspect the chromatograms to
determine if the device is processing correctly. If the chromatograms are OK, return the device
to normal operation.
10.14 Replace the digital controller assembly
This section presents the procedures for removal and installation of the digital controller assembly and
mounting bracket.
To remove the digital controller assembly:
1.
On the Analyzer Operation screen, click
Hold
under Next Mode. When the device completes the
current cycle and enters hold, continue to the next step.
2.
Gain access to the digital controller assembly by loosening the countersunk hex socket locking
set screw in the front end cap using a 1/16” hex wrench then unscrewing the end cap.
3.
Using a flat blade screwdriver, loosen the screw in the mounting clamp.
4.
Unplug the ground cable from the digital controller assembly.
5.
Slide the assembly off of the thermal flask, being careful to not unplug the flat ribbon cable
connecting the digital controller assembly to the termination panel or the lithium battery.
NOTICE – Equipment damage or loss of data.
Do not remove the board-mounted
lithium battery or the termination panel cable. Removing the lithium battery will cause a
cold start which may not be desirable. When replacing the lithium battery, the termination
panel cable must remain connected to power the digital controller assembly; otherwise, the
device will cold start.
6.
To reassemble, perform steps 3–5 in reverse order, being careful to align the display screen
horizontally before tightening screw.
