The Turtle Tough VRS Valve Retractable Conductivity sensors have been designed for a wide measurement range in difficult process conditions. They can be installed in submersion, insertion, or hot-tap configurations, and are good for most applications from high purity water to high chemical concentrations. Wetted materials of construction are 316 stainless steel and PEEK, with alternate materials available on request. All possible leak paths through the sensor are double sealed with EPDM O-rings for maximum on-stream reliability. The front O-rings isolate the back ones from chemical attack, giving more than double the service life that can be expected from single sealed units. Process connections are made via a bored through swage fitting with 3/4″ NPT threads. This fitting can be screwed into a line, a tank, or the optional wet-tap valve assembly. It can also be turned around and connected to a standpipe for use in a submersion configuration. Available cell constants range from 0.01 to 20.0 giving it a very broad scope of applications.