Filter
Top Products
Getting Started Model T265 Chemiluminescence Ozone Analyzer Addendum to Model T200 Manual
22
Step Action Comment
6. Press EXIT,
input Span gas
The Model T265 returns to the CAL menu. Now allow
span gas to flow passed the instrument.
7. Wait 30 min Wait for the O
3
reading to stabilize at the span value
(watch O
3
STB).
8. Press SPAN The SPAN button should be displayed once the
concentration approaches the span value. In certain
circumstances at low span concentrations both the
ZERO and SPAN buttons will appear. Do not press
ZERO again when running span gas!
9. Press ENTR Pressing ENTR to span the instrument actually changes
the equations so that the concentration displayed is the
same as the expected span concentration you entered
above, thus spanning the instrument.
10. Press EXIT Pressing EXIT returns the instrument to SAMPLE
mode.
IMPORTANT IMPACT ON READINGS OR DATA
Over time PMTs lose sensitivity, which is reflected by an increase in the O
3
slope test
function during ongoing calibrations. If the slope falls outside the range of 0.7 to 1.3,
a hardware adjustment to the PMT gain is required. The process involves the
adjustment of both a high and low gain potentiometer, located on the preamp printed
circuit board, while noting the “NORM PMT” test function value, for a particular
concentration of Ozone span gas. Typically, the high voltage to the PMT is adjusted,
such that, the “NORM PMT” is twice the measured O
3
concentration. See PMT Sensor
Hardware Calibration
in the Model T200 manual’s Troubleshooting &Service
section for detailed procedures.
Step 3 - Review Quality of calibration: Calibration Quality Check Procedure
Step Action Comment
1. Scroll the TEST
function menu until the
O
3
SLOPE is
displayed.
The SLOPE value for O
3
should be 1.0 ± 0.3. If
the SLOPE value is in the acceptable range the
instrument will perform optimally.
2. Scroll the TEST
function menu until the
O
3
OFFS is displayed.
The Model T265 will display the offset
parameter “O3 OFF” for the O
3
equation. This
number should be near zero. A value of ±10
indicates calibration in the optimal range.
The Model T265 is now ready to measure sample gas.
07337B DCN6324