SEMTECH® DUAL FID
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Emissions Measurement Solutions SEMTECH® DUAL FID Real-Time THC Measurement Innovation. Built on Experience. The SEMTECH® Dual FID (Flame Ionization Detector) simultaneously measures the Total HydroCarbon (THC) and Methane (CH4) fractions of a gaseous sample using two vacuum flame ionization detectors combined in a single assembly. Only one sample line, one FID fuel line and one combustion air source are required to provide both measurements. CH4 measurement is provided by flowing the gaseous sample through a Non-Methane HydroCarbon (NMHC) cutter assembly which removes all hydrocarbons but methane from the original sample. The system is designed to minimize the loss of hydrocarbons prior to analysis by maintaining the required temperature through the use of a heated filter, heated sample line and stainless steel fittings, all of which have low hydrocarbon adsorption characteristics. User-selectable measurement ranges ensure accuracy for a wide variety of test applications. Principle of Operation: The SEMTECH® Dual FID uses two flame ionization detectors combined in a single assembly for the simultaneous measurement of the THC and CH4 fractions of a gaseous sample. The FID chambers must first be heated to 191°C. The Warm-up time is approximately half an hour. Once the dual FID chamber reaches set point temperature, FID fuel and combustion air are allowed in to the FID chambers and both flames ignite automatically. The exhaust sample is injected in a single input manifold and is then split into two equal fractions. The first fraction is directed towards the THC channel FID chamber. The second fraction is initially directed towards a NMHC oxidation catalytic chamber for removal of the NMHC fraction from the sample, leaving only methane in the sample, which is then injected in the CH4 channel FID chamber. The sample fractions are then injected in the respective FID chambers, where they are mixed with FID fuel and combustion air at the bottom of the detectors’ flame jets and burned on the flames’ tips. As the hydrocarbons burn, they form positively charged ions. These ions are repelled by the jet’s nozzle head to which a positive bias voltage has been applied. The positive ions are then attracted to the negatively charged collector plate, creating a current measured in real-time. Actual THC and/or CH4 concentrations are calculated from this measurement.

Automatic Flame Ignition: the FID flame will light automatically after approximately 30 minutes of warm-up time. Dual Flame Ionization Detector Assembly: the single assembly dual detector system, coupled with an NMHC cutter assembly upstream of the CH4 FID, provides both THC and CH4 measurements in real-time using only 1 sample line, 1 FID fuel line and 1 combustion air input. Measuring Range: the Dual FID has 4 user-selectable measurement ranges for each channel, ranging from 0-100 ppmC1 to 0-30000 ppmC1. Sample Handling: the water trap and Nafion™ dryer are integrated into the SEMTECH®...