Detcon 1000 - Manual (Page 19)

Mdl 1000 H2S E-Chem / Inst. Air
Model 1000 H2S E-Chem w Instrument Air Rev. 1.1 Page 15 of 28
6. Calibration and Maintenance
The Model 1000 Series H
2
S Process Analyzer is calibrated prior to shipment. Only minimal adjustment
should be required at time of commissioning. However, it is highly recommended that a zero and span
calibration be performed twice in the first week of operation to assure optimum system performance. After
that, a recalibration interval of every month is recommended.
Maintenance
When the Acetic Acid Bubbler option is used, the 5% acetic acid solution (or white vinegar) should be kept
near the Max fill mark on the bottle. The level should be checked monthly and the entire solution contents
should be changed every 6 months.
Material Requirements
9 Detcon Part Number 327-000000-000 MicroSafe™ Programming Magnet.
9 Detcon Part Number 942-001123-000 Zero Air cal gas. (Ambient air can be used, if it can be verified that
no target gas is present).
9 Span gas cylinder containing H
2
S gas in background N2 (nitrogen) as per the following range table. If
available, span gas cylinders in background Methane (natural gas) or air can also be used.
6.1.1 Zero Calibration
Zero Calibration should be performed quarterly in the field. The AutoZero function is used to zero the sensor.
The dilution airflow (with sample turned off) can be used to zero calibrate the sensor. Alternately, a zero air or
N
2
cylinder connected to the calibration port can be used.
1) Turn the sample flow mass control off, leaving only the airflow to provide the zero gas. Allow the unit 5
minutes to stabilize.
2) Enter the calibration menu by holding the programming magnet stationary over “PGM 1” (see above) for 3
seconds until the display reads “1-ZERO 2-SPAN”, and remove the magnet. Note that the “CAL” LED
comes on.
3) Enter the zero menu by holding the magnet stationary over “PGM 1” for 3 seconds until the display reads:
“AUTOZERO”, and remove the magnet. The sensor will enter the auto zero mode. When complete the
sensor will display “ZERO COMPLETE” for 5 seconds and then return to the normal operation menu,
“0.00PPM H2S”.
4) Re-open the sample flow mass control and re-establish the target sample flow rate per the arrow indicator
on the H
2
S sample Rotameter.
6.1.2 Span Calibration
Table 3 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 →” 1000 or 2500
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