The photometric probe is sensitive to the color change of acid chrome K and naphthol green B mixed indicator when Ca 2+ and Mg 2+ are titrated with EDTA.
Field experiment was carried out in Guanzhong area, Shaaxi province using Capsicum as indicator, to study Capsicum to fertilizer effect reaction of n, p, K fertilizer.
在陕西省关中土娄土区布置线辣椒缺素大田试验，研究线辣椒对氮、磷、钾肥的肥效反应。
3
In the estimation of ore body's grade, it is important for founding correctly power indicator of the reverse K square distance method.