Metir plc manufactures and sells equipment used monitoring water for toxins and pathogens in the United Kingdom, the United States, Europe, China, and internationally. The company provides compact mass spectrometers and the Modern Water MicroTox CTM, FX, and LX toxicity monitors; consumables and spare parts; toxicity monitoring in water; and point-of-need contaminant detection, as well as support and consultancy services. It sells its products through OEMs and distribution sales channels. The company was formerly known as Microsaic Systems plc and changed its name to Metir plc in February 2025. Metir plc was incorporated in 1998 and is based in York, the United Kingdom.