To all who are knowledgeable of ORP meters
In Malaysia a craze has been started regarding ORP and TDS meters. Several ponds have been measured via the use of a hanna meter and standardised solutions. The name of the solution is H17020 - a REDOX solution for platinum & gold electrodes - which will give a standard reading of 200 to 275mV. The lable listed the contents as: Potassium Hydrogen Phthalate (877-24-7) & Quinhydrone (106-34-3). It is a pre-mixed solution. The ORP meter was soaked into this solution and the reading is over 220mV, so is the reading at Hanna Industries's lab which shows a reading of 245mV.
the ORP reading for the chlorinated tap water is 300mV whereas the filtered tap water reading is 100mV. test with potassium permanganate were also done an indicated the sharp rise in mv readings.
Several ponds were measured and their readings were rather low across the board the highest being in a bakki showered pond with 500kg of bacteria house (I do not know the pond size) the reading was only 125mV. The pond is not overstocked at all.
All the kois look great and some are jumbo size the water clarity is clear and no foam layer as an indication of DOCs. Water parameters are great and TDS value is about 75. Water is filtered by charcoal filters before entering the pond to remove chlorine
Could anyone please suggest a reason as to why they may have such low readings. Would ORP readings be affected by temperature like TdS and the meter have to be calibrated to a certain reading at a certain temperature.
Could more DOCs be dissolved in the water at higher temperature.
The meter was calibrated by qualified science graduate who do products presentation. Your help would be much appreciated
06-07-2004
Linear Mode
Similar Threads 
