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5.0 CALIBRATION AND CAL CHECKS
Unlike most NOx analyzers, the T200U-NOy does not have a sample inlet port
on its rear panel. The sample inlet is located on the external Converter.
Follow the steps in the T200U manual to:
Enter the expected NO and NOy span gas concentrations in the
analyzer.
Do the zero calibration procedure
Do the span calibration procedure
The analyzer always routes the zero/span gas through the external Converter. In
standard configuration, the calibration gas needs to be input at the CAL IN (3)
port of the 501Y bypass pump. In all cases, the calibration gas delivered must be
under a small amount of pressure (2-5 psig) to overcome the resistance of the
tubing.
NOTE
There must be no venting of the Zero or Span gas to atmosphere prior to the analyzer. The
gases actually vent at the external Converter.
Calibration gas must be provided for both the 501Y bypass system and the
analyzer. Flow requirements are 0.80 LPM for NO bypass, 0.80 LPM for NOy
bypass and 1 LPM for the analyzer. Calibration gas flow must be in sufficient
excess (~4 LPM) to prevent any ambient air from entering the sample inlet of the
external Converter.
The maximum 50 ft length of tubing between the 501Y and the remote Converter
has been proven to generate too much backpressure for some brands of
calibrators. Teledyne calibrators are designed to overcome this potential issue.
We strongly recommend that span calibration be done with NO span gas. Span
checks can be done with one of: NO only, NO2 only, or a mixture of NO and NO2
(GPT).
Zero air used for all calibration procedures, including GPT, should have <1 ppt
NO and NO2, less than 1 ppt of major interferents such as SO2, NH3,
hydrocarbons and a dew point of -5oC or less. The calibration gasses should be
from a reliable supplier, since the quality of the tank concentration values
ultimately determines the accuracy of the analyzer.
NOTE
The T200U-NOy does NOT have equivalency approval.