Most processed products pass through a particulate phase, or involve the use of particulate materials at one or more stages of manufacture, processing, and finishing.   The same is true of the preceding "evolutionary" phases of research and development.

In consequence, there are many Industrial and Research situations in which obtaining a small sample from a given volume of powder is a pre–requisite.   Typically this may be research, analysis, product or process development, production control, quality control, etc.   The degree of success of 'the next step' depends on such a sample representing the material from which it was derived, as closely as possible.

Since correct assessment and optimum use of particulate materials for whatever purpose requires representative samples, and segregation is a natural consequence of storage, handling, and transportation, a simple reliable procedure is commonly needed.   Our Spinning Rifflers offer this facility at modest cost.   In fact, the cost consequences of using an unrepresentative sample tend to be excessive as compared to deriving a good sample at the outset.   For example, derailing a research project or performing a series of unreconcilable analyses, in place of one which is repeatable, are examples of excessive costs (perhaps not immediately obvious and thus probably unrecognised) which can result from poor or unregulated sampling.

To paraphrase, spoons are for stirring, serving, and supping from, but should be banned as implements for sampling, as should spatulas.   There is a danger of finding out a great deal about some small quantity of powder which is not representative of the bulk from which it came.   Our range of riffling instruments, on the other hand, offers a simple and dependable method by which samples may be obtained, which have compositions approaching closely those which are theoretically obtainable from an original, larger volume of material.   The Rifflers offer a cost effective solution to the representative sampling problem and should be applied as universally as possible to the derivation of representative samples of powders.   Our instrument selection is outlined below.

Model Name	Nominal Capacity	Nominal Divisions Ratio   Percentage		Discrete Portions	Representation of the relative volume in sample portions, after subdivision, in each model of Spinning Riffler.	Foot Notes
MSR	25 mL	20:1	5	20		1, 2
SR1A	1 L	16:1	6·25	16		1
SR1B	1 L	16:1	6·25	6		1, 2
SR1AB	1 L	16:1	6·25	up to 6, or all 16		1, 2
SR5B	5 L	16:1	6·25	2		1, 2
SR5B4	5 L	16:1	6·25	4		1, 2
SR10A	10 L	20:1	5	20
SR10A-B	10 L	20:1	5	4
		5:1	20	4
SR40B	40 L	8:1	12·5	8
SR40AB	40 L	40:1	2·5	See note 3		3

Note 1

These instruments have a common drive unit and frame.   Only the hopper and sample collection facilities differ, which are interchangeable from the MSR to the SR5B4 inclusive.

Note 2

By omitting a collection vessel one less discrete sample will be collected, with the proportion collected as the bulk sample increasing correspondingly.

Note 3

For the SR40AB, two of the nominal five litre samples may be collected as splits of one plus four, or of two plus three.   It follows that a sample, nominally of any number of fortieths of the original volume, may be derived with a suitable arrangement of collectors.