Teledyne gfc 7000ta operation manual Before Calibration, Zero Air and Span Gas

Calibration Procedures Model GFC7000TA Carbon Dioxide Analyzer

7. CALIBRATION PROCEDURES

This contains a variety of information regarding the various methods for calibrating a Model GFC 7000TA CO2 Analyzer as well as other supporting information.

NOTE

The procedures in this assume that the calibration password feature is disabled (the instruments default state). If it is enabled a password prompt screen (See Section 6.9) will appear after the CAL, CALZ or CALS buttons are pushed but before the instrument enters the associated calibration mode.

7.1. Before Calibration

The calibration procedures in this assume that the Range Type, Range Span and units of measure have already been selected for the analyzer. If this has not been done, please do so before continuing (See Section 6.8 for instructions).

All Gas lines should be PTFE (Teflon), FEP, glass, stainless steel or brass.

NOTE

If any problems occur while performing the following calibration procedures, refer

to Section 11 of this manual for troubleshooting tips.

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 analyzer’s readings. Zero air should contain less than 25 ppb of CO2 and other major interfering gases such as CO and Water 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 CO2 mixed with Zero Air or N2 at the required ratio.

Zero air generators that condition ambient air by drying and removal of pollutants are available on the commercial market such as the Teledyne Instruments Model 701 Zero Air Generator. We recommend this type of device, in conjunction with bottled N2 for generating zero air.

Teledyne Analytical Instruments 161