How it works

The GC955 118 Methane analyser is designed to provide fast mid-range measurements in cities and industrial environments. It is a gas chromatograph equipped with a compact oven with a column that effectively separates methane (CH4) from other hydrocarbons. 

The methane analyser uses a method that not only measures the concentrations of the greenhouse gas methane but simultaneously presents the sum of all other hydrocarbons, including ones that are usually difficult to detect such as oxygenated hydrocarbons.

The analyser uses a FID detector which generates two distinct peaks: one for methane and one for total non-methane hydrocarbons (TNMHC). The gas sample passes through the special layered column. Methane passes through and is first injected into the detector and then 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. Producing measurements using a 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 GC955 118 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