We have a “calgaz” bottle with 10,000 ppm of Methane in it, which is used as the control sample. We were hoping to image the methane coming out of the bottle. However, I was unable to image it at all.  Why?

GasFindIR will not "see" these type of concentrations within the cylinders because they are typically very low.  For example, a calibration cylinder that has 10,000 ppm of methane may be diluted with up to 99.75% nitrogen. 

The reason we can not see most of the leaks from TVA calibration cylinders (calgaz) is because the path length times concentration these cylinders are capable of providing is too small.  Most of these cylinders are designed to provide a small plume, literally only millimeters in diameter.  This is because the TVAs have intake sniffer snouts that are only millimeters in diameter so there’s no reason for the cylinders to provide a larger plume.  Anything larger then the intake snout is simply overkill.  In our case however we see mass.  There are 2 ways to provide contrast mass.  You can either boost the concentration in that millimeter diameter stream or you can keep the small concentration but make the stream much larger in size, like meters in diameter as opposed to mm.  Either way what you’ve done is to place more absorbing molecules along your line of sight, i.e. between your imager and the thermal background.  That’s why we don’t see most of these calibration cylinders, they just weren’t designed to deliver mass, they were designed to deliver small well maintained concentrations.