Getting StartedModel T265 Chemiluminescence Ozone Analyzer Addendum to Model T200 Manual
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| 6. | Press EXIT, | The Model T265 returns to the CAL menu. Now allow |
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| input Span gas | span gas to flow passed the instrument. |
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| 7. | Wait 30 min | Wait for the O3 reading to stabilize at the span value |
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| (watch O3 STB). |
| 8. | Press SPAN | The SPAN button should be displayed once the |
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| concentration approaches the span value. In certain |
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| circumstances at low span concentrations both the |
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| ZERO and SPAN buttons will appear. Do not press |
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| ZERO again when running span gas! |
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| 9. | Press ENTR | Pressing ENTR to span the instrument actually changes |
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| the equations so that the concentration displayed is the |
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| same as the expected span concentration you entered |
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| above, thus spanning the instrument. |
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| 10. | Press EXIT | Pressing EXIT returns the instrument to SAMPLE |
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| mode. |
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IMPORTANT | IMPACT ON READINGS OR DATA | ||
Over time PMTs lose sensitivity, which is reflected by an increase in the O3 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 O3 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 |
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1.Scroll the TEST function menu until the O3 SLOPE is displayed.
2.Scroll the TEST function menu until the O3 OFFS is displayed.
Comment
The SLOPE value for O3 should be 1.0 ± 0.3. If the SLOPE value is in the acceptable range the instrument will perform optimally.
The Model T265 will display the offset parameter “O3 OFF” for the O3 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.
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07337B DCN6324
