Hach, 6028P020, Encapsulated Differential pH Sensor, LCP Body, 5-Wire with Internal Preamplifier, Glass Electrode, 20 ft Cable

LCP (Liquid Crystal Polymer), Convertible Mounting Style, 6m Analog Cable, 5-Wire with Built-In Preamplifier, General Purpose Glass pH Electrode
Exceptional Performance with the Differential Electrode Measurement Technique
This field-proven technique uses three electrodes instead of the two normally used in conventional pH sensors. Process and reference electrodes measure the pH differentially with respect to a third ground electrode. The end result is unsurpassed measurement accuracy, reduced reference junction potential, and elimination of sensor ground loops. These sensors provide greater reliability, resulting in less downtime and maintenance.
Lower Maintenance Needs with the Replaceable Salt Bridge
The salt bridge creates a barrier to contamination which minimizes the dilution of the internal standard cell solution. The result is lower maintenance needs and a longer time period between calibrations.
Built-in Preamp or Two-Wire Transmitter
The built-in preamp produces a strong signal, enabling you to locate the analyzer up to 3000 ft. (914 m) from the sensor. An optional built-in two-wire transmitter is available for applications requiring a 4-20 mA sensor signal. This option requires that the indicating instrument of the measuring system be capable of providing 24 VDC to power the sensor, and have adjustment means to calibrate for zero offset and span.
Versatile Mounting Styles
1.5 inch NPT threads are provided on both ends of the convertible mounting style sensor for either mounting into a pipe tee or attaching to the end of a pipe for immersion. The convertible style enables you to consolidate inventory, and thereby reduce associated costs. A union-mount style sensor and mounting tee are also available to conveniently install and remove the sensor for in-line service.