
ECA 450 Calibration
Instruction 0024-9400
11. Press ENTER to calibrate the analyzer’s Measured value to that of the
Applied value; after which the message “Good Calibration” should appear
along with the Calibration List screen being redisplayed.
If the message “Sensor Output Low” or “Sensor Not Calibrated” appears,
refer Section “5.4 Troubleshooting Guide.”
12. Turn off regulator; then remove gas cylinder from calibration fixture.
3.9 Calibrate SO
2
Sensor
This procedure spans the optional Sulfur Dioxide sensor to a known gas level.
Note: The SO
2
sensor cannot be installed without the NO
2
sensor also being
installed.
Material Required:
• Calibration Gas Fixture (Section 3.2)
• Gas Cylinder: 100 ppm SO
2
(refer to Section 6.2)
Procedure:
1. Enter Calibration List screen; then choose SO2 per Section 3.3 to display
the CALIBRATE SO2 screen. At the conclusion of this step the pump
should be running.
2. Using the Gas Fixture shown in Figure 3-1, attach an SO
2
calibration gas
cylinder to the analyzer’s GAS inlet port.
3. Adjust regulator of calibration fixture for a flow meter indication of
approximately 2 SCFH.
4. Wait until Measured reading on screen stabilizes (approximately
3 minutes). Then use the
∧∨ and < > keys to enter an Applied value that
equals the concentration stamped on the SO
2
gas cylinder.
The calibration range is from 10 to 150 ppm. An applied value that is
outside this range will cause the message “Bad Calibration Entry” to
appear.
Typical Calibrate SO
2
Screen During Calibration:
«««CALIBRATE SO2««««
Measured 98 ppm
Applied 00100 ppm
5. Press ENTER to calibrate the analyzer’s Measured value to that of the
Applied value; after which the message “Good Calibration” should appear
along with the Calibration List screen being redisplayed.
If the message “Sensor Output Low” or “Sensor Not Calibrated” appears,
refer Section “5.4 Troubleshooting Guide.”
6. Turn off regulator; then remove gas cylinder from calibration fixture.
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