Fluoride Probe Assembly

The pH600/762 fluoride probe assembly is a loop-powered, isolated fluoride sensor with all power being supplied from the two-wire current loop connection. Isolation enables the probe to be at a potential relative to ground without affecting the integrity of the measurement. The two-wire connection eliminates the requirement of a separate supply in addition to the loop supply voltage.


  • Temperature-compensated measurement.

  • Two-wire field mounted transmitter – suitable for multiple-loop installations with a central controller.

  • Isolated 4-20mA signal.

  • Simple pushbutton operation.

  • Tough IP65 die-cast Aluminium enclosure.

  • Plug and socket connectors for easy installation and maintenance.

  • Tool-free operation – no dip-switches or potentiometers.

With a Model 762 probe assembly and electrodes, the pH600 transmitter becomes a complete fluoride/RmV sensing unit. The pH600 transmitters include all the circuitry necessary for the measurement and transmission of an isolated 4-20mA signal, which is then linearised in. All the transmitter’s functions are accessible through the pushbutton interface – there are no potentiometers or dip-switches. Calibration of the signal is accomplished using a one-point offset to grab. The pH600 can also temperature compensate readings using a 100Ω TC element.

The Model 762 assembly is manufactured from chemically resistant polypropylene and has spaces for two PG13.5 electrodes – an industrial fluoride ISE electrode and glass temperature compensator. The reference is a double-junction arrangement with a large gel reservoir giving excellent stability in tough applications.

Tecnical Specifications

Fluoride (ppm)

Range 0.1ppm to 100.0ppm

Resolution 0.1ppm

Accuracy ±0.1ppm


Range 50mV to -186mV

Resolution 1mV

Accuracy ±1mV


Temperature Range -10°C to 110°C

Resolution 0.1°C

Accuracy ±0.5°C

Resolution 1mV

Accuracy ±2mV

Temperature Compensation Auto (Pt100) / Manual (0° to 100°)

Number of Calibration Points 1 (offset to grab sample)

Inputs Asymmetrical/Symmetrical

Outputs 4.0mA to 20.0mA

Under-range Current Output 3.8mA/4mA (selectable)

Over-range Current Output 3.8mA/20mA (selectable)

Hold Current Output 22mA/Last Value (selectable)

Display Custom LCD

Power Requirements 12V to 24V dc

Load Resistance 600 ohm Max

Ordering Information

500/0060 Complete Fluoride probe assembly: pH600, 762 holder, electrodes and 40cm wand

Part of the SDI group

Astles Control Systems Ltd

B3 Regent Park, Summerlys Road,

Princes Risborough, Bucks, HP27 9LE

t: 01844 273301


Copyright © 2019 - 2020 Astles Control Systems Ltd