Detcon 1000 - Manual (Page 15)

Mdl 1000 H2S E-Chem / Inst. Air
Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 11 of 28
4. Start Up
Upon completion of all tubing connections and field wiring the Model 1000 Series Process Analyzer is ready
for startup. Note that after power is applied, varying readings may occur during sensor warm-up. Allow at
least 1 hour for stabilization (24 hours is best). With sample gas and air flowing, apply system power and
observe the following normal conditions:
a) DM-624 “Fault” LED’s are off.
b) A reading close to the anticipated H
2
S level should be indicated upon conclusion of a 1-minute “warming
up” cycle.
NOTE: All alarms will be disabled for 1 minute after power up. In the event of power failure,
the alarm disable period will begin again once power has been restored.
1. Set the sample pressure to 10psig and verify the proper set point at the pressure gauge.
2. Assure that the Instrument Air is set to 10psig at the input to the Air Inlet Port.
3. Set the airflow through the Air Flow Rotameter. Adjust the Rotameter Airflow valve to the value noted in
Table 2 (Air Flow Column) and in alignment with the “ →” mark on the Rotameter.
NOTE: Sample flow rates must be actual Rotameter set-point flow rates, after properly
accounting for Rotameter gas density effects, see Table 2.
Table 2 Sample Flow Rate
DM-624 Range
(ppm)
Sample Flow
(cc/min)
Air Flow
(cc/min)
Span Gas Flow
(cc/min)
H
2
S Cal Gas
(ppm)
0-10 200 Labeled “S →” 500 250 Labeled “C →” 10
0-20 200 Labeled “S →” 500 250 Labeled “C →” 10
0-25 200 Labeled “S →” 500 250 Labeled “C →” 10
0-50 200 Labeled “S →” 500 250 Labeled “C →” 10 or 25
0-100 200 Labeled “S →” 500 250 Labeled “C →” 25 or 50
0-150 200 Labeled “S →” 500 250 Labeled “C →” 25 or 50
0-500 80 Labeled “S →” 1000 100 Labeled “C →” 100
0-5000 200 Labeled “S →” 800 250 Labeled “C →” 1,000 or 2,500
0-10,000 80 Labeled “S →” 800 100 Labeled “C →” 2,500 or 5,000
0-2% 200 Labeled “S →” 750 250 Labeled “C →” 5,000
4. Adjust the sample mass flow controller valve per Table 2 to meet the designated sample flow target mark
labeled as “S →”. The “C→” indicator on the Rotameter shows what Flow rate to calibrate at if the cal gas
is N
2
. If the cal gas is in methane, then span gas flow should be set to “S →”.
NOTE: A displayed methane (typical natural gas) sample flow of 200cc/min. is actually equal
to 250cc/min. of nitrogen when accounting for the 20% gas density affect on the Rotameter. A
displayed methane flow of 80cc/min. is actually 100cc/min. when accounting for the density
effect.
5. Set the Airflow Rotameter per the Air Flow value in Table 2 that corresponds to the DM-624 Sensor
Range.
6. Proceed with calibration per Section 6 Calibration and Maintenance.