How it works
The Alpha 116 Gas Chromatograph (GC) is designed for continuous stack monitoring of methane and other hydrocarbons with high-range detection limits, up to 1000 ppm.
The Alpha 116 GC uses 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.This analytical approach ensures precise measurement of total air pollution.
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 116 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
Datasheet
Specifications
Detector
FID
Cycle time
3 minutes
Gas consumption
FID: Zero air, quality 5.0, dry and clean, Methane free, 2.5 bar, 250 ml/min, Hydrogen, quality 5.0, 3.5 bar 25 ml/min No nitrogen required, but if zero air may contain Methane, use of nitrogen as carrier gas is advised
LDL-Range Methane (PPM)
1-1000
LDL-Range TNMHC (PPM-C)
(1-1000)
Repeatability
<1% of FS
Spandrift
<0.25% of FS /week
Zerodrift
<0.01 ppmc/week
Linearity
<1% of FS
Included hardware
Industrial x86 based computer, hard disk, full colour touch screen
Included software
Windows Embedded Standard, GC Software
Communication
Direct control by touchscreen, keyboard or mouse. External data communication via RS232, analog and digital outputs, via TCP-IP.
GC specifications
Column cage with special application column, 10 port valve. Loop depending on required concentration range, flame ionization detector (FID)
Calibration
Internal calibration switch for calibration zero and span gas, gas stream required 25 mL at 1 atm pressure. The Delta 116 CEMS has an option to have this functionality.
Power demand
230 V AC, 200 VA (115 V AC available) 50/60 Hz
Conditions
5 OC TO 40 OC, 20 TO 95% RH
Approvals
CE approval for EMC conformity: EN 55022, EN 61000-4-2, EN 61000-4-3, EN 61000-6-2, EN 61000-6-3, EN 61010, EN 61326
Extra functions
Combination with Multi Channel Selector:
- type VICI dead end or flow through, 6 to 16 streams, pump 5 L/min (internal) or on demand external.
- Combination with RS232 alarm out puts 4-20 mA up to 15 streams.
