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Getting Started
Model 400E Ozone Analyzer
Instruction Manual
38
P/N 04316 Rev: B
3.3.1.
Zero Air and Span Gas
To perform the following calibration you must have sources for Zero Air and Span
Gas available for input into the sample port on the back of the analyzer. For this
type of analyzer, Zero Air and Span Gas are defined as follows:
SPAN GAS
A gas specifically mixed to match the chemical composition of the type of gas being
measured at near full scale of the desired measurement range. In the case of O
3
measurements made with the T-API Model 400E Ozone Analyzer it is recommended
that you use a Span Gas with a O
3
concentration equal to 80% of the measurement
range for your application.
EXAMPLE: If the application is to measure between 0 ppm and 500 ppb, an
appropriate Span Gas would be 400 ppb. If the application is to measure
between 0 ppb and 1000 ppb, an appropriate Span Gas would be 800 ppb.
Span Gas can be created using a Dynamic Dilution Calibrator such as the T-TAPI
Model 700 or an Ozone Calibrator such as the T-API Model 401.
ZERO AIR
A gas that is similar in chemical composition to the earth’s atmosphere but
scrubbed of the gas being measured by the analyzer in this case O
3
. A zero air
generator such as the T-API Model 701 can be used to as a source of Zero air.