Hanna Instruments HI 83203 Instruction Manual

24 25• Press TIMER and the display will show the countdown prior to the measurement or, alternatively, waitfor 2 minutes and 30 seconds and press READ. When the timer ends the meter will perform the reading.• The instrument displays the results in mg/L of total chlorine.Note: free and total chlorine have to be measured separately with fresh unreacted samples following therelated procedure if both values are requested.INTERFERENCESInterference may be caused by: Bromine, Iodine, Ozone, Oxidized forms of Chromium and Manganese.In case of water with hardness greater than 500 mg/L CaCO3, shake the sample for approximately 2minutes after adding the powder reagent.In case of water with alkalinity greater than 250 mg/L CaCO3 or acidity greater than 150 mg/L CaCO3,the color of the sample may develop only partially, or may rapidly fade. To resolve this, neutralize thesample with diluted HCl or NaOH.Total ChlorineTotal Chlorine• Press ZERO key. The meter will show “-0.0-” when the meter is zeroed and ready for measurement.• Remove the cuvette.Powder reagents procedure• Add 1 packet of HI 93711-0 DPD reagent. Replace the cap andshake gently for 20 seconds (or 2 minutes for seawater analysis).• Reinsert the cuvette into the instrument.• Press TIMER and the display will show the countdown prior to themeasurement or, alternatively, wait for 2 minutes and 30 seconds andpress READ. When the timer ends the meter will perform the reading.The instrument displays the results in mg/L of total chlorine.Liquid reagents procedure• To an empty cuvette add 3 drops of HI 93701A-TDPD1 indicator, 3 drops of HI 93701B-T DPD1 buffer and1 drop of HI 93701C DPD3 solution. Swirl gently to mixand immediately add 10 mL of unreacted sample.Replace the cap and shake gently again.• Reinsert the cuvette into the instrument.x 3x 3 x 1