Semiconductive Trimethylamine Gas Sensor for Detecting Fish Freshness

ABSTRACT Characteristics were studied on In 2 O 3 treated with 5 mol% MgO responses to 300 ppm trimethylamine (TMA), dimethylamine (DMA), ammonia and other gases evolved from several different fish muscles stored under different conditions. Sensitivities of the In 2 O 3 ‐MgO sensor element were higher in order of TMA, DMA and ammonia over the operating range 330–620°C. Sensor responses were directly proportional to concentrations of TMA in fish muscle in the presence of other evolved gases, irrespective of types of fish muscle or storage time.