Above: ORPScan Waterproof Tester
Oxidising biocides are widely used for the elimination of water borne bacteria. Automatic dosing units are often employed to maintain biocide levels at suitable concentration. Redox units are common throughout industry for controlling dosing units, to ensure sufficient active biocide is present. Pump and controller together enables automatic “reactive” dosing to cope with spikes in biocide requirements. Maintenance on such units is minimal, but to ensure correct control, periodic checking of Redox controller accuracy is important.
Info Centre >> Water Treatment Technical Manual >> 3. ORP/Redox >> 3.3 Redox Standards & Checking
To confirm meter accuracy 475mV, 263mV and 83mV standards are available. Redox standard 475mV is a ready prepared solution. Redox standards at 263 and 86mV can be prepared as follows:
Redox Standard - 263mV @ 25oC
1. Take a 20ml sample of Kittiwake pH 4 Buffer Solution.
2. Add a small quantity (approx 0.05-0.1g) of Quinhydrone Powder.
3. Shake vigerously to mix.
(Very little quinhydrone will dissolve, so the solution will end up grey/black).
4. The Redox Standard is now ready for use.
5. Discard after use.
Redox Standard 86mV @ 25oC
1. Take a 20ml sample of Kittiwake pH 7 Buffer solution.
2. Add a small quantity (approx 0.05-0.1g) of Quinhydrone Powder.
3. Shake vigerously to mix.
(Very little quinhydrone will dissolve, so the solution will end up grey/black).
4. The Redox Standard is now ready for use.
5. Discard after use.
Order Information
AS-K24893-KW 475mV Redox Standard 500ml
AS-K20011-KW pH 4 Buffer Solution 500ml
AS-K20008-KW pH 7 Buffer Solution 500ml
AS-K24891-KW Quinhydrone Powder 10g