Specifications

PCA
®
3
79
If the sensor’s output is too low to be usable, then the
message “Bad Calibration Sensor End of Life” will appear
followed by the CALIBRATION LIST screen being re-dis-
played. The sensor will now be marked as being BAD in the
DIAGNOSTICS screen.
10. Turn OFF the regulator and remove the gas cylinder.
NOTE: A CO-only calibration can be done by pressing F3 in
Step 5 (instead of ENT).
5.8 SO
2
Sensor Calibration
This procedure spans the optional sulfur dioxide sensor to a known
gas level.
Material Required:
• Calibration Kit, P/N 0024-7059
• Gas Cylinder: 100 ppm SO
2
in Nitrogen, P/N 0024-1158
Procedure:
1. If not already done, turn ON
the analyzer and display the
CALIBRATION LIST screen per
Section 5.2.
2. Use the ▲▼ buttons to highlight SO
2
,
and then press ENT to display the
CALIBRATE SO
2
screen.
“Measured” is the current SO
2
reading,
while “Applied” is a known SO
2
level
that will be applied for calibration
purposes.
3. Attach a 100 ppm SO
2
cylinder to the
regulator of the calibration fi xture
shown in Figure 5-2 on Page 85.
4. Use the ▲▼ and ◄► buttons to enter
an Applied value that exactly equals
the concentration stamped on the SO
2
cylinder.
The calibration range is from 9 to
1,800 ppm. An attempt to calibrate outside this range will
cause the message “Bad Calibration Wrong CAL Entry” to
appear in the following step.