
Conductivity & Resistivity Sensors
When It Has To Be Accurate
- Our Sensors monitor a number of important measurements:
- The effectiveness of the filtration process for potable water
- The mineral parts-per-million in desalination systems
- The total dissolved solids for waste water treatment applications
- The purity of water in applications where electroconductivity must be avoided
- The purity of water to be used in pharmaceutical, hydrogen fuel cell, and semiconductor processes
- When it has to be accurate, think Pathfinder Instruments!
Pathfinder RC-20 Resistivity Probe
Pathfinder RC-20 Resistivity Probe (K=.007) provides accurate measurement of ultra pure water for Pharmaceutical, Hydrogen Fuel Cell, and Semiconductor applications.
The RC-20 is a Resistivity/Conductivity Probe that has an Integral Temperature Sensor for automatic temperature compensation. It comes in a variety of cable lengths. Standard cable length is 10 ft, and custom lengths are available up to 60 ft.
The RC-20-SS (shown) has two advantages over the standard unit with the 3/4” NPT male plastic fitting. It will operate at a higher pressure and the SS fitting has ½” NPT male threads allowing it to be used in smaller pipelines.

Pathfinder HPT-12 Resistivity Transmitter
The Model HPT-12 Transmitter converts the resistivity cell signal to a usable 1-1.2 VDC output proportional to the Megohm/cm level using an RC-20 probe.
Reliable Conductivity Measurement for Water
Conductivity transmitters are analytical transmitters designed for monitoring electrical conductivity levels within a given solution for industrial process, pharmaceutical production and water quality monitoring. Conversely, resistivity transmitters monitor how strongly a solution opposes the flow of electric current.
Conductivity measurements are used routinely in many industrial and environmental applications as a fast, inexpensive and reliable way of measuring the ionic content in a solution. For example, the measurement of product conductivity is a typical way to monitor and continuously trend the performance of water purification systems.