Our Portable Odorant Detector is designed to increase accuracy over traditional stain tubes and reduce operation costs. It is ideal for both distribution operators and pipeline pickling service companies. Detection Range: Tetrahydrothiophene (THT): 0-10 or 0-100 ppm tert-Butyl Mercaptan (TBM): 0-10, 0-100, or 0-500 ppm.