Discussion on the method for determining moisture content in compound fertilizers
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How fast can the results be obtained for measuring the moisture content in compound fertilizers? What methods are used to measure moisture? Our company uses the drying method. Let’s discuss it together. This post was last edited by Canghai Yili Sha on 2009-3-2 02:57.]
To measure moisture in an analysis laboratory, the direct drying method is generally used. However, this method is suitable for measuring only a constant amount of moisture. Aside from this approach, it is also possible to use a moisture meter – that is, to calibrate the moisture meter using KF reagent, with 10 µL of distilled water being used to determine the concentration of the KF reagent, after which the measurement can be taken. The formula is T=10÷1000V (T is the concentration of Karl Fischer) ； V is the volume of Karl Fischer reagent consumed during calibration). After the concentration is determined, a sample is taken to measure the moisture content; the calculation formula is (% = T × V1 ÷ M), where T is the concentration of the Karl Fischer reagent ； V1 is the amount of Karl Fischer reagent consumed during titration ； M is the amount of sample weighed)
How long does it take for the direct drying method and the Karl Fischer titration respectively? For the direct drying method, it usually takes about 3 hours in our factory – is that a bit long?
“Problems with Using KF to Determine Moisture” http://bbs.hcbbs.com/thread-392012-1-2.html
If you use the direct drying method to measure moisture, you can set the oven temperature to 105 degrees; one and a half to two hours will be sufficient； If you use the Karl Fischer method, it will take less time. You first need to calibrate the concentration of the Karl Fischer reagent using distilled water before you can determine the moisture content; in terms of time, this might take about half an hour.