Portable handheld colorimeter LH-C01 can test residual chlorine ion concentration in the water.It can detect and analyse the sample very fast by only three steps:start,zeroing and reading with small capacity(only 220 with battery).
Method：DPD method，residual chlorine react with the DPD reagent，the color of the sample change to be red.
Operating conditions:0 to 40℃,0 to 90% relative humidity (noncondensing)
Life of battery：1×9V,more than 40h
shutdown：Press the “ON/OFF” button to shutdown the colorimeter after the test.
DPD method. The most common method for free chlorine is the DPD method. At near neutral pH chlorine oxidises the DPD to form a magenta coloured compound. However this method only works for low chlorine levels up to approx 10 ppm. At higher chlorine levels the reaction proceeds beyond the magenta coloured compounds with a 'bleaching out' of the deeper colour.
Normally chloramines only react slowly with DPD. To include chloramines in tests using DPD some iodide is added before the DPD. The iodide reacts with the chloramines to form a compound that will react with DPD to form a magenta colour. So after iodide is added to the test solution and then after DPD is added, the final colour will represent free and combined chlorine. This is called Total chlorine. So to find combined chorine alone, two tests are carried out, one with iodide and the other without iodide added.
In a variation of the DPD test, rather than rely on visual or instrument measurement of intensity of the magenta colour, some kits use a titration. This works for both the free and combined components. The titrant is a reducing agent that converts the magenta coloured compound to form a colourless solution. Chlorine is calculated from the amount of titrant used.
1.How about your quality warranty ?
Normally all Lohand products are supplied with a warranty of 12 Months from the date of shipment.
2.How do you deliver the goods ?
We send by sea or by air including DHL,FedEx,TNT,UPS etc.
3.What if there are problems for the produts?
Usually we check again before shipment, if there are broken items, we will replace for you soon.