GDS-68XP Operation & Maintenance Manual, Revision 3.4
Page 25
SEQUENCE
Switch
Sequence
Time
Purge / Hold
Time
Total Cycle Time
(Approximate)
0
On-Demand Sequence
1 hour
1
12-15 min
40 min
1 hour
2
12-15 min
105 min
2 hours
3
12-15 min
165 min
3 hours
4
12-15 min
225 min
4 hours
5
12-15 min
285 min
5 hours
6
12-15 min
345 min
6 hours
7
12-15 min
465 min
8 hours
Figure 6-2: Sequence Timing
BYPASS
disables the sequencer and allows sample gas to flow directly into the sensor for testing
purposes. To enter BYPASS mode, press and hold the BYPASS button. To exit Bypass, press and hold the
RUN button. Bypass mode will automatically exit after 15 minutes of operation.
Bypass is only available
during Purge/Hold sequence.
RUN
Pressing RUN for five seconds during the Purge/Hold sequence will initiate a new cycle.
L1 AND L2
indicate the status of the sequencer processor.
MODE
L1 (RED)
L2 (GRN)
PUMP
VALVE
DESCRIPTION
START-UP
SIMULTANEOUS FLASH
OFF
OFF
FIRST 8 SECONDS ONLY
WARM-UP
ALTERNATE FLASH
ON
OFF
INITIAL WARM-UP ONLY
3
ON-DEMAND
SLOW FLASH
OFF
ON
2
OFF
WAITING FOR REMOTE “START”
ACTIVE SAMPLE SEQUENCE
CONDITION
1 FLASH
OFF
OFF/ON
1
ON
GAS APPLIED TO SENSOR FOR 10 SEC
DELAY
1 FLASH
OFF
ON
OFF
PURGE AIR FOR FIVE MINUTES
CHARGE
2 FLASHES
OFF
OFF/ON
1
ON
GAS APPLIED TO SENSOR
READING
3 FLASHES
OFF
OFF/ON
1
ON
IDENTIFY PEAK, STORE READING
RECOVERY
4 FLASHES
OFF
ON
OFF
PURGE AIR TO < 10% OF FULL SCALE
Purge / Hold Mode
PURGE/HOLD
OFF
2 FLASHES
ON
2
OFF
SENSOR AIR PURGE
2
BYPASS MODE
ALTERNATE FLASH
OFF/ON
1
ON
RAW SENSOR INPUT TO CHANNEL 1
CAL MODE
SLOW FLASH
OFF
ON
OFF
PURGE AIR FLOWING TO SENSOR
1)
Pump is ON if sample draw, OFF if positive pressure.
2)
Pump runs intermittently
3)
15 minute warm-up starts once sensor output reaches stable value (+/- 10% of scale)
Figure 6-3: L1 / L2 Indicator Operation