David R. Battiste

Improved changeover time between regular and GC–IR on the Digilab FTS‐15B

The time needed to change from regular to GC–IR (gas chromatography–infrared spectroscopy) operation on the Digilab FTS‐15B Fourier transform infrared spectrometer has been reduced by 40–45 min. First, a single‐pole double throw switch connected to the detector selection circuitry on the signal board was mounted in the sample compartment. Second, a 1‐in.‐diam hole was cut into the top of the purge cover above the position of an operational amplifier that is used to adjust the peak height of the interferogram center burst. These modifications increase the ease and convenience of setting up and removing the GC–IR hardware, allow better utilization of an ’’older’’ model optical bench which requires placement of the GC–IR light pipe in the sample chamber, and provide a time savings.