Zero Air And Span Gas; Table 7-1: Nist - Standard Reference Materials (Srm) For Carbon Monoxide - Teledyne 300E Instruction Manual

CALIBRATION PROCEDURES

7.1.1. Zero Air and Span Gas

To perform the following calibration you must have sources for Zero Air and Span
Gas available.
Zero Air is similar in chemical composition to the Earth's atmosphere but scrubbed
of all components that might affect the analyzers readings. Zero air should contain
less than 25 ppb of CO and other major interfering gases such as CO
Vapor. It should have a dew point of -5°C or less
Span Gas is 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. It is
recommended that the span gas used have a concentration equal to 80% of the full
measurement range.
If Span Gas is sourced directly from a calibrated, pressurized tank, the gas mixture
should be CO mixed with Zero Air or N
ALL calibration gasses should be EPA Protocol gasses or NIST traceable standards.
Table 7-1: NIST – Standard Reference Materials (SRM) for Carbon Monoxide
SRM #
1680b
1681b
2613
2614
Zero air generators that condition ambient air by drying and removal of pollutants
are available on the commercial market such as the T-API Model 701 Zero Air
Generator. We recommend this type of device for generating zero air.
124
Type
(Liters @ STP)
CO in N2
CO in N2
CO in Zero Air
CO in Zero Air
Model 300E Carbon Monoxide Analyzer
at the required ratio.
2
NOTE
Volume Nominal Concentration
870
870
870
870
Instruction Manual
and Water
2
(PPM)
500
1000
18.1
43.0
P/N 04288 REV: A