USF Wallace & Tiernan DEPOLOX 4, Manual

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10. REDOX ANALYSER
The Redox analyser consists of a Redox probe, an impedance transformer, a special
probe cable and a plug-in amplifier. For combined chlorine and Redox measurement,
the transparent cell block of the DEPOLOX 4 chlorine measuring cell serves as flow-
through assembly. If only the Redox value has to be measured, a special flow-through
assembly is available.
10.1 REDOX PROBE WITH SPECIAL CABLE
The Redox probe is equipped with a ceramic membrane and a silver/silver chloride
reference potential. The 3.0 mol KCL gel electrolyte does not require replenishment.
NOTE!
Do not remove the hose from the filling hole.
The Redox probe is equipped with a special connector. Check that the o-ring is still
on the unit prior to connection. Also with the Redox probe, an impedance transformer
is used to convert the very high ohmic signal into a low ohmic signal. The supplied
screened coaxial cable of 1.5 m length is equipped with a special plug on one end.
Fasten this plug to the impedance transformer connector unit. The other end of the
screened cable has to be connected directly to the corresponding terminal in the basic
unit. The max. distance is 50 m.
10.2 START-UP
The start-up procedure for the Redox analyser is the same as that for the pH-value
analyser.
A solution that generates 468mV (Pt Ag/AgCl, 3 mol KCL, E-100 278) serves as buffer
solution.
Immerse the probe in this solution and wait for 10 minutes. Activate manual operation
mode, press key "F" until "Cal. mV" is displayed and select the buffer solution value
by pressing the direction keys. Press key "E" to enter this value (max. ± 50 mV).
The Redox probe is now calibrated. The factory settings are similar to those in the pH
amplifier, the factory-set measuring range is 400...900 mV.
NOTE:
The running-in of a Redox probe takes several hours. This factor has to be taken
into consideration to achieve a correct Redox measurement.
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