Halitosis Measuring Device uses a highly sensitive semiconductor as a detector along with a small built in column enabling quick separation of the sample gas. OralChroma is a portable gas-chromatograph device that was developed to measure VSCs levels (hydrogen sulfide, methyl mercaptan, and dimethyl sulfide) inside the mouth providing high sensitivity and practicality, then displays each gas concentration on a PC in nanogram/10ml and ppb (parts per billion).