
GDS-68XP Operation & Maintenance Manual, Revision 3.5
Page 11
Type
Target
Gas
Range
Part
Number
Temp
Range
Warm
‐
Up
15
Hydrogen
Sulfide
0
‐
10
ppm
to
0
‐
5000
ppm
10
‐
9815
‐
Rxxxx
0°C
to
+
50°C
2
to
4
hours
30
Mercaptan
(TBM)
0
‐
15
ppm
0
‐
50
mg/m3
0
‐
3.00
lbs/mmcf
10
‐
9830
‐
R0015
10
‐
9830
‐
R0050
10
‐
9830
‐
R0003
0°C
to
+
40°C
4
to
8
hours
31
THT
0
‐
15
ppm
0
‐
3.00
lbs/mmcf
10
‐
9831
‐
R0015
10
‐
9831
‐
R0003
0°C
to
+
40°C
12
to
24
hours
40
Odorants
0
‐
15
ppm
0
‐
3.00
lbs/mmcf
10
‐
9840
‐
R0015
10
‐
9840
‐
R0003
0°C
to
+
50°C
2
to
4
hours
41
Spotleak
0
‐
15
ppm
0
‐
3.00
lbs/mmcf
10
‐
9841
‐
R0015
10
‐
9841
‐
R0003
0°C
to
+
50°C
2
to
4
hours
Figure 3-1: Toxic Sensor Characteristics
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 3-2: Sequence Timing
RECOMMENDED
MINIMUM
SAMPLE
SEQUENCE
TIMES
GAS
TYPE
MINIMUM
COMMENTS
15
HYDROGEN
SULFIDE,
LOW
RANGE
(<
50
PPM)
1
HOUR
FOR
MAXIMUM
SENSOR
LIFE,
USE
LONGEST
POSSIBLE
SEQUENCE
15
HYDROGEN
SULFIDE
(>
500
PPM)
2
HOURS
FOR
MAXIMUM
SENSOR
LIFE,
USE
LONGEST
POSSIBLE
SEQUENCE
31
TETRAHYDROTHIOPHENE,
0
‐
50
MG/M3
2
HOURS
TWO
HOURS
IS
REQUIRED
FOR
COMPLETE
SENSOR
RECOVERY
FROM
METHANE
30
MERCAPTAN,
0
‐
50
MG/M3
OR
0
‐
3
LB/MCF
4
HOURS
FOUR
HOURS
IS
REQUIRED
FOR
COMPLETE
SENSOR
RECOVERY
FROM
METHANE
40,
41
GENERAL
ODORANTS,
INCLUDING
SPOTLEAK
2
HOURS
TWO
HOURS
IS
REQUIRED
FOR
COMPLETE
SENSOR
RECOVERY
FROM
METHANE
Figure 3-3: Recommended Minimum Sequence Times