ECA 450
Calibration
Instruction 0024-9400
59
3.11 Calibrate NO
2
Sensor
This screen is used to span the optional Nitrogen Dioxide sensor to a known
gas level.
Material Required:
• Calibration Gas Fixture (Section 3.2)
• Gas Cylinder: 100 ppm NO
2
(refer to Section 6.2)
Procedure:
1.
Enter Calibration List screen; then choose NO2 per Section 3.3 to display
the CALIBRATE NO2 screen. A
t the conclusion of this step the pump
should be running.
2.
Using the Gas Fixture shown in Figure 3-1, attach an NO
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 NO
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 NO
2
Screen During Calibration:
«««CALIBRATE NO2««««
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.