Incremental sampling

Calculation of Sample Extraction Increments Sample quantities taken in an extraction increment are calculated in accord with the mechanical sampler employed. The following three examples illustrate calculations for three commonly used sampling methods. 

If the material being sampled consists of discrete particles such that an average particle mass can be calculated, then still another method is useful. In this procedure the constants and B of Equation 5 are obtained from the intraclass correlation coefficient between pairs of small, single-increment samples of equal mass, the increments of each pair being collected near each other and the pairs distributed over the population under study. The value of r can be estimated from the relation ... 

Whenever increment/sample masses are not identical, estimation of the total lot mass, Al must be done as a weighted mean from the analytical results, lest an additional IWE be introdnced. 

This chapter introduced application of simple variographic experiments as a basis for problem-dependent deliberations as to an optimal deployment of increment/sample sampling rate, r, and/or compositing using Q increments/sample. The variographic experiment constitutes the most powerful process sampling data analysis tool available. 

Preliminary test method increment (sample) collection, processing, and analysis... 

Segregation errors, which are due to segregation within the bulk and can be minimized by suitable mixing and the use of a large number of incremental samples to form a larger test sample. 

Changing the sample plan to reduce variability between field replicates - for example by stratified sampling or by increasing the number of increment samples that make the composite sample. 

There are two procedures for solid waste sampling load sampling from the truck and incremental sampling. ... 

Tables 2 and 3 present the chemical analyses data. Table 4 shows the free water, and Table 5 shows the pH for increment samples. Table 6 gives size distribution data. Tables 7 through 10 address radium, uranium, and thorium results, and Table II lists emission spectrographic analyses.

Reduction of bulk sample size is performed either manually by successive quartering the bulk sample, by increment sampling or by using rotation sampling devices. 

It is important to understand the principles of sampling and be aware of the precautions that are necessary to obtain a representative laboratory sample. Definitions of the terms increment, sample, spot sample, composite sample and laboratory sample are given in the Glossary. Figure 6.1 illustrates how they are related. 

References Society of Mining Engineers, Minerals Processing Handbook, Norman L, Weiss, ed, chap, 30, Sampling and Testing , part 2. Theory and Practice of Incremental Sampling , Littleton, Colorado, 1985. Gy, Pierre M.,... 

To collect a high number of samples which will form the overall sample. These aliquots, called incremental samples, are taken from a single place in the lot. 

Quantitation by the standard addition technique Matrix interferences result from the bulk physical properties of the sample, e.g viscosity, surface tension, and density. As these factors commonly affect nebulisation efficiency, they will lead to a different response of standards and the sample, particularly with flame atomisation. The most common way to overcome such matrix interferences is to employ the method of standard additions. This method in fact creates a calibration curve in the matrix by adding incremental sample amounts of a concentrated standard solution to the sample. As only small volumes of standard solutions are to be added, the additions do not alter the bulk properties of the sample significantly, and the matrix remains essentially the same. Since the technique is based on linear extrapolation, particular care has to be taken to ensure that one operates in the linear range of the calibration curve, otherwise significant errors may result. Also, proper background correction is essential. It should be emphasised that the standard addition method is only able to compensate for proportional systematic errors. Constant systematic errors can neither be uncovered nor corrected with this technique. 

The samples of raw material were taken directly at the farms. Several incremental samples were taken randomly from the whole lot and combined to the aggregate sample. After homogenisation and grinding of the aggregate sample in the lab, a laboratory sample of 1.5 kg was taken for the examination and stored at 8°C for mycotoxicological analyses. 

In the framework of all the sampling procedures, an increment sample is taken the complex composite and gross samples are created from these increments, and from this, the test sample is taken for a certain type of testing or analysis. 

To test the hydrodynamic robustness of the surface, the samples were exposed to a 3.2 mm in diameter high-speed water jet with varying dynamic pressures. Contact angle measurements were taken at 10 second increments. Samples were exposed imtil saturation (pores start soaking up... 

Size Analysis Procedures Based on Incremental Sampling of an linitially Homogeneous Suspension... 

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