The 270-WQ201 pH Sensor is a rugged reliable water pH measuring device. The pH transmitter is mounted on 25' of marine grade cable, with lengths up to 500' available on request. The pH sensor output is 4-20 mA with a three wire configuration. The pH transmitter's electronics are completely encapsulated in marine grade epoxy within a stainless steel housing. The pH transmitter also uses a removable shield and replaceable pH sensor element for easy maintenance.