Detcon 1000_H2S - Manual (Page 22)

Model 1000 H2S Echem
Model 1000 H2S Echem Instruction Manual Rev. 2.8 Page 18 of 30
1) Verify that the current calibration gas level is equal to the calibration span gas concentration. (Refer to
Section 5.2.3 Program Mode, “View Sensor Status”. The item appears as “CAL LEVEL @ ### PPM”.)
2) If the calibration gas level setting is equal to the calibration span gas concentration, proceed to item “3)”.
If the calibration gas level setting is not equal to the calibration span gas concentration, adjust the
calibration gas level setting so that it is equal to the calibration span gas concentration.
a) Enter the programming menu by holding the programming magnet stationary over “PGM 2” for 30
seconds. When the display reads “VIEW PROG STATUS”, withdraw the magnet. Scroll through
the programming menu by momentarily waving the programming magnet over “PGM 1” or “PGM 2”.
The menu options are: View Program Status, Set Alarm 1 Level, Set Alarm 2 Level, Set Heater Level,
and Linearize Sensor.
b) From the programming menu scroll to the calibration level listing. The menu item appears as: “SET
CAL LEVEL”. Enter the menu by holding the programming magnet stationary over “PGM 1” for 3
seconds until the display reads “CAL LEVEL @ ### PPM”, and withdraw the magnet. Use the
programming magnet to increase (PGM 1) or decrease (PGM 2) the display reading until the reading is
equal to the desired calibration span gas concentration.
c) Exit to the programming menu by holding the programming magnet over “PGM1” for 3 seconds.
d) Exit back to normal operation by holding the programming magnet over “PGM 2” for 3 seconds, or,
the sensor will automatically return to normal operation in 30 seconds.
3) Enter the calibration span menu by holding the programming magnet stationary over “PGM 1” for 3
seconds. The display will read “1-SPAN 2-EXIT”. Hold programming magnet stationary over “PGM 1”
for 3 seconds to proceed with span. “APPLY ## PPM” will appear in the display for 10 seconds.
4) Turn the H
2
S 3-way valve so that the arrow is pointing toward the cal gas source. The sample is now
being drawn from the H
2
S Calibration Port.
5) Turn the fixed flow regulator on the Cal Gas Bottle to the “ON” position, and set the sample rotameter
mass flow valve so the flow is set to “C” on the rotameter. The airflow should be set per the Air Flow
table. (See Table 3 for these values).
6) As the sensor signal changes, the display will change to “AUTOSPAN ###”. Where “###” indicates the
actual gas reading. The reading will increase/decrease until the sensor stabilizes. When the sensor signal
is stable, the sensor will auto span to the requested concentration and the display will change to “SPAN
COMPLETE” for two seconds and then “REMOVE GAS” for 3 seconds. The analyzer will then return
to normal operation. The Auto Span sequence takes approximately 5 minutes.
7) Turn the fixed flow regulator on the Cal Gas Bottle to the “OFF” position and remove the gas.
NOTE: If the circuitry is unable to adjust the span to the proper setting the sensor will enter
into the calibration fault mode which will cause the display to alternate between the sensor’s
current status reading and the calibration fault display: “CAL FAULT”.
8) Turn the 3-way valve so that the arrow is pointing toward the sample source. Establish the target sample
gas flow through the sample rotameter adjusting the flow rate to the “S” reading. Set the air rotameter per
Table 3 (Air Flow column) and the appropriate H
2
S gas range for the analyzer.
Span calibration is complete. The total time for span calibration is approximately 10 minutes.
Additional Notes
a) Upon entering the calibration menu, the 4-20mA signal drops to 2mA and is held at this level until the
sensor returns to normal operation.
b) If during calibration the sensor circuitry is unable to attain the proper adjustment for span, the sensor will
enter into the calibration fault mode which will activate fault alarm functions and cause the display to
alternate between the sensor’s current status reading and the calibration fault screen which appears as:
“CAL FAULT”. If this occurs, attempt to recalibrate by re-entering the calibration menu. If the sensor
fails again, refer to Section 13, Troubleshooting.