The J.U.M. Engineering Model 109A, or JUM 109A, uses two individual detectors and two individual signal amplifiers. The sample is introduced into one FID for THC reading. The same sample is also run through a non-methane cutter which eliminates all hydrocarbons except methane. The analyzer subtracts the two numbers to compute a THC less methane reading. This item is also available for rent from CleanAir Europe.