EN 12619 - Total VOCs by FID Flashcards
What is the principle of Flame Ionisation Detection?
EN 12619
- Sample gas and fuel gas pulled into combustion chamber
- Mixture mixed with combustion air and ignited
- HC’s cracked and electrical charge measured by electrometer amplifier.
- Amount of charge is proportional to amount of carbon in sample.
EN 12619
Should the filter upstream of the sample line be heated?
EN 12619
Yes
EN 12619
Where should the calibration inlet position be?
EN 12619
Upstream of the filter
EN 12619
What temperature should the sample line be heated to?
EN 12619
Heated to between 180°C and 200°C
EN 12619
What is allowable for the zero check following zero and span gas calibration?
EN 12619
No significant change on the zero reading
EN 12619
What is the allowable deviation on the pre-test zero and span gas line checks?
EN 12619
< 2% of the span gas value
EN 12619
What specification of zero gas is required?
EN 12619
Synthetic air (Purity of 99.998%)
EN 12619
What specification of span gas is required - type and MU
EN 12619
Propane
(Expanded uncertainty ≤ 2%)
EN 12619
What must the concentration of the span gas be for regulatory work?
EN 12619
Approximately at the half hourly ELV or 50 to 90% of the analyser range
EN 12619
What is maximum allowable analyser response time?
EN 12619
200 seconds to reach 90% of the range
EN 12619
What is the maximum allowable sample residence time?
EN 12619
< 60 seconds
EN 12619
What is the allowable uncertainty at a 95% confidence interval?
EN 12619
± 15%
EN 12619
What is the stated range of the method?
EN 12619
0 to 1000 mg/m³
(can be extended if Annual Systems Check lack-of-fit tests performed at higher ranges)
EN 12619
What are the 2 fuel gas options for the method?
EN 12619
- 100% Hydrogen
- Hydrogen / Helium mix
EN 12619
What is the allowable post-test drift?
EN 12619
0 to 2% - no drift correction is applied
2 to 5% - drift correction is applied
> 5% - drift test fails and test must be reperformed
EN 12619
