The two principles of soil sampling
The first step in soil analysis is sampling. Common sampling instruments and tools include aluminum boxes and ring knives. When collecting soil samples, the soil should be divided into thousands of plots, ie sampling units, depending on the difference in soil (eg, parent material, topography, hydrological conditions, water management, etc.). The soil of each sampling unit should be as uniform as possible. As for the size of each sampling unit should be, it should be based on the differences in soil and the purpose of the study. First, take more mixed samples It is generally believed that there are two purposes of sampling: one is to measure the average fertility of soil in one location, and the other is to identify the variability of soil fertility. Theoretically speaking, in a lot, samples are taken at multiple points to determine their effective nutrient content, and the mean value is then calculated by means of mathematical statistics. This value should be consistent with the measured value of the multi-sample mixed sample. Sex. This method of multiple sampling and separate determination can provide people with an opportunity to understand the changes in nutrient availability in the area. However, because it brings more workload at the same time, the method of multi-point mixed sample measurement is still generally used in practical work. In addition to taking account of the heterogeneity of the soil itself, the methods for multi-site mixed sample collection should also take into account the distances from different parts of the root group to the fertilization furrows, the soil levels, and artificial or natural differences, and then take more Point the "homogeneous" sample and mix it to make it a mixed sample. Second, according to different research purposes to determine the sampling position For different research purposes, the locations of collected soil samples are also different. Such as: To study the changes in fertilization in soil, should be sampling in the fertilization ditch, to study the absorption of roots for nutrients, it should be sampling near the rhizosphere, to study the movement of nutrients in the soil, it should be in the rhizosphere soil And sampling at different distances from the root, to study the laws of nutrient movement at different levels, it is necessary to sample different soil levels. To study the basic fertility characteristics of the soil, reference can be made to soil survey methods, ie taking the main section and the auxiliary section, and sampling according to different genetic levels. In general production and scientific research, in order to compare nutrient differences at different soil levels, press 0 more. Samples are taken at different levels such as 20 cm, 20-40 cm, 40-60 cm. Related Instruments: Soil Analyzer http://
Conveyor Idler seals are used to keep substances such as grease and lubricant in, while keeping dirt, fluids, and other contaminants out. One advantage to this type of seal is that when small amounts of leakage occur across the seal, as is inevitable, contaminants from the outside still can't get all the way inside, and the materials being sealed may not make their way all the way to the other end. This minimizes fouling caused by mixing of contaminants and sealed fluids.
The labyrinth seal has a number of grooves which interlock with other grooves or teeth. This differs from most traditional seals, which use a single lip in an attempt to seal an opening. With the labyrinth seal, each groove acts as its own lip, distributing pressure across the seal rather than concentrating it in one area. While a labyrinth seal cannot deal with high pressure differentials, it can be used in many other types of environments.
Two of the most important things that must be accomplished in order to extend bearing life is to keep lubrication in, and contamination out. That`s the important function of a seal. There are many types of seals that can serve various functions.
Labyrinth Seal,Idler Roller Labyrinth Seal,Conveyor Roller Labyrinth Seal Shandong Xinkaite Bearing Co., Ltd. , https://www.idlerbearing.nl
