HANNA Instruments Water Analysis Division has released the HI93711 Free and Total Chlorine meter. It is a microprocessor-based colorimeter for measuring free or total chlorine in the range of 0mg/L to 2.5mg/L (free) and 0mg/L-3.5mg/L (total).
Measurements are made by colorimetric analysis, adding a reagent to the sample. The method is an adaptation of the USEPA-recommended DPD method 330.5. The reaction between chlorine and the DPD reagent causes a pink tint in the sample, proportional to the level of chlorine present.
The LCD displays the results. Measurements are simple, quick, inexpensive and effective with 0.01mg/L increments and an accuracy of ±0.3mg/L (±3% of the reading). Reagents and accessories are purchased separately.