Hach-Lange POLYMETRON 8398 - Manual (Page 8)

Inductive Probe 8398
5
2.2 Principle of inductive technology
1 : Receiver
2 : Oscillator
3 : Cables
4 : Thermoplastic insulator
5 : Receiver
6 : Transmitter
7 : Induced current
The 8398 probes are made up of two coils that are completely insulated from the
process:
x The primary (or transmitter) coil, supplied with alternating voltage, produces an
alternating electromagnetic field that generates an electrical current in the solution.
x The secondary (or receiver) coil detects the size of the weak current induced by
the movement of ions in the solution.
The absence of contact between the electrical part and the solution (magnetic
coupling) provides a large number of advantages compared to the traditional
technique using metallic electrodes:
x No polarisation and hence a broad measurement range.
x High chemical and mechanical resistance.
x Possibility of performing measurements in soiling products.
x Perfectly hygienic design.