How it works

The Alpha 115 Gas Chromatograph (GC) is designed to measure concentrations of greenhouse gas methane in the ambient air. The Alpha 116 GC ensures precise measurement of total air pollution through using a method that not only measures the concentrations of the greenhouse gas methane but simultaneously determines the sum of all other hydrocarbons, including ones that are typically difficult to detect such as oxygenated hydrocarbons.

Integral to this approach is a FID detector, which generates two distinct peaks: methane and total non-methane hydrocarbons (TNMHC). The gas sample goes through a specialised process within a layered column, where methane is passed through and injected into the detector before the column is ‘back flushed’ and all of the other hydrocarbons pass to the detector. This results in the two peaks generated by the FID. Using true gas chromatographic separation prevents potential problems with catalytic conversion used in other indirect measurements.

Each gas analyser is equipped with all of the essential components: FID detector, computer, colour touchscreen, and GC software. The Alpha 115 model holds a CE approval for EMC conformity.

For optimal running of the analyser, it it is important to have a good source of Methane-free zero air. A zero air generator must run with a catalytic methane scrubber, working at a temperature of at least 400 oC. Alternatively, nitrogen can be used as carrier gas using zero air only for the detector air supply.

Synspec produces 5 different versions of Methane/TNMHC analysers:

• Synspec Alpha 115: Mid range for ambient air measurements in cities or near industries
• Synspec Alpha 116: High range for stack measurements up to 1000 ppm
• Synspec Delta 116 CEMS: High range for stack measurements according to US EPA 25A
• Synspec GC955 114: Low range for background measurement
• Synspec GC955 118: Fast mid range ambient air measurements in cities or near industries

Servicing

Servicing information