Sampling

“ This person or group should periodically inspect and repair all equipment and keep track of the use and location of sampling equipment when it is signed out. Sampling pumps should be calibrated with each use. ”

“ Check the pump during sampling to determine that the flow rate has not changed. If sampling problems preclude the accurate measurement of air volume, discard the sample. Take two to four replicate samples for quality control for each set of field samples.
(6) Record pertinent sampling data including location of sample, times of beginning and end of sampling, initial and final air temperatures, relative humidity and atmospheric pressure or elevation above sea level. ”

“ For lots of less than ten drums, unless there is reason to suspect want of uniformity, it should usually suffice to draw the sample from one drum selected at random by the sampler. The analyst, or person who undertakes the sampling, must, however, exercise discretion as to the scheme of sampling to be followed, especially if want of uniformity of the several lots constituting the consignment in suspected. The size of the lumps constituting a sample will be referred to later.
The British Association's regulations lead to a sample weighing about 3 lb. being obtained from each drum. ”

“ The sampling pump used to collect the sample must also be compatible with the sampling needs and the media used. Specifically, the pump must be capable of maintaining the desired flow rate over the time period needed using the sampling media specified. Some pumps may not be able to handle the large pressure drop of the media. This will be true for fine mesh (smaller than 40 mesh) solid sorbent tubes, small pore size filters or when attempting to take a short-term sample on a sorbent tube of a higher than normal pressure drop at a flow rate of 1 L/min or greater. ”

“ Whether through consultation with the laboratory or through reading the specific measurement method, the sampling media will be specifically identified, e.g., pore size and type of filter, concentration and amount of liquid media required, and specific type and amount of solid sorbent (see Tables 1, 2 and 3 for common types, characteristics and behavior of sampling media) . If specific brand name products are called for, no substitutions should be made. Most sampling media are well defined through research and testing ”

“ Remove the filter holder plugs and attach the filter holder to the personal sampling pump with a piece of flexible tubing. Clip the filter holder to the worker's lapel. Air being sampled should not be passed through any hose or tubing before entering the filter holder.
(4) Prepare the field blanks at about the same time as sampling is begun. These field blanks should consist of unused filters and filter holders from the same lot used for sample collection. Handle and ship the field blanks exactly as the samples, but do not draw air through the field blanks. ”

“ This formulation consists of limiting the questions to a small enough number to be handled in a short space of time and to a wide enough range to represent every possible degree of trade skill. The questions are tabulated and are then ready to be used in the final sampling process.
Final sampling is made by testing twenty men who are known to be typical representatives of each group (novice, apprentice, journeyman, expert) . Among the novices tested are some highly intelligent and mature men of good general knowledge but no trade ability. ”

“ Since simple random sampling often does not ensure a representative sample, a sampling method called stratified random sampling is sometimes used to make the sample more representative of the population. ”

“ It is also important that the sampling system allow the operator to perform all the necessary calibration and sampling procedures without compromising the speed and flexibility of the analytical system. Figure C2 illustrates a sampling system con figuration that meets these requirements, though other configurations are possible. A computer controls the actions of the interferometer and records the voltage output of the IR detector throughout the motion of the interferometer's optical element. ”

“ Precision, Bias, and Accuracy
Results from four sets of samplers used in the analyte recovery experiment, the sampling and analysis experiments (e.g., the environmental parameters experiments) , and the sample stability experiment can be used for the estimation of precision, bias, and accuracy of the method. A more exacting treatment of this is described elsewhere [1] . Sampler results from the multi-level factorial design at the 0.1, 1.0, and 2.0 times the exposure limit value; the sampler stability experiment (at 0.5 times the exposure limit) ”

“ Prepare filter by adding 0.5 mL 0.26 N sulfuric acid to glass fiber filter on a glass tray. Heat for 1 hour at 100 °C. Load the filter, backed by a paper O-ring, into a cassette and seal with shrink band to enable open-face sampling. 2. Personal sampling pump, 1 to 2 L/min, with flexible tubing. ”

“ Personal sampling pump, 0.02 to 5 L/min or other rate suitable for filling sample bag, with flexible connecting tubing. NOTE: Pumps lubricated with petroleum products should not be used. 3. Sample bags, Tedlar, 1- to 20-L or other appropriate sizes. ”

“ These also aid in establishment of analyte purity. Potential sources of this information include chemical reference books, health hazard evaluation reports, bulk sample analyses, material safety data sheets, chemical process information, etc. Since innovation is a key element in the sampling and analytical method development process, detailed experiments for the initial development of the sampling approach and optimization of the analytical procedure are better left to the discretion of the researcher. ”

“ Darning-samplers are usually square, or nearly square, in shape, and are simply finished with a single line of hem-stitching at the edge, but some of the older ones are ornamented with a broader band of drawn-work as border; while a few have examples of drawn-work, alternating with squares and crosses of darning, in the body of the sampler. A small section of such a sampler, dated 1785, is illustrated on an enlarged scale in Fig. 77. It has a series of small conventional leaf patterns worked in single drawn-work, and edged with a scalloping worked in chain-stitch with green silk. ”

“ The stitches exemplifying the mode of darning damask, cambric, or linen had usually a sampler entirely devoted to them, and at one period—the end of the eighteenth century—it seems to have been a fairly general custom that a girl should work one as a companion to the ordinary sampler of lettering and patterns. The specimen darns on such a sampler are, as a rule, arranged in squares or crosses round some centre device, a bouquet or basket of flowers for instance, or it may be merely the initials of the worker in a shield. ”

“ Sampson, "it's such a comfort to hear you say them beautiful facts after getting such a jar from that minx of a Ruby's poetry!"
"Let us sit on this log at the roadside," says I, "and forget the inhumanity and ribaldry of the poets. It is in the glorious columns of ascertained facts and legalised measures that beauty is to be found. In this very log we sit upon, Mrs. Sampson," says I, "is statistics more wonderful than any poem. The rings show it was sixty years old. At the depth of two thousand feet it would become coal in three thousand years. ”

“ Mr Joseph Pennell’s Sampler, which finds a place here as a specimen of American work, has little to distinguish it from its fellows that were produced in England in the reign of George IV. The border, it is true, only preserves its uniformity on two of the four sides, but where it does it is designed on an old English pattern, that of the wild strawberry. So, too, we find the ubiquitous stag and coach dogs, Noahs, ash trees, birds, and flower baskets.
The sampler itself is a beautiful specimen of drawn work, and the lettering is the same colour as the linen. ”

“ The sampler should be drawn much larger than it is here represented—say about 10 × 71⁄2 inches—and might be placed on the linen in the frame as sketched, leaving a good space below and at the side for practice. If the frame is 20 inches long, or larger still, it will hold this sampler and the next one. It is a good thing to have a nice set of samplers to keep, as one often finds it necessary to be reminded of suitable stitches, which will not always come to mind when wanted. ”

“ Four other rows complete the sampler, which only measures 181⁄2 × 63⁄4. In order to give it a larger size the lowest row is not reproduced. I have seen another drawn-work sampler which antedates that just described by a year. It is of somewhat coarse texture but is good in design, and bears in a panel at the side initials and the date. The Victoria and Albert Museum has also two somewhat similar drawn-work samplers—one by Elizabeth Wood, dated 1666, which contains the Stuart S’s; the other (undated) has the arms of James I.
[Pg 59]
Larger Image Fig. ”

“ Larger Image Plate XXIV.—Darning Sampler. 1788.
Darning Samplers of unpretentious form date back a long way, but those where they were conjoined to decoration, as in the specimens reproduced here, appeared to cluster round the end of the eighteenth century. Not only are a variety of stitches of a most intricate kind set out on them, but they are done in gay colours, and any monotony is averted by delicately conceived borderings. Whilst “Darning Samplers” cannot be considered as rare, they certainly are not often met with in fine condition. ”

“ As to these there is an interesting extract extant, from the inventory of St James’s House, nigh Westminster, in 1549, wherein among the items is one of “a table [or picture] whereon is a man holding a sword in one hand and a sceptre in the other, of needlework, prettily garnished with seed pearls.”
[14] A very good example of a sampler in drawn-work, in which the floral form of decoration is entirely absent, save in the sixth row (the pinks) , which is in green silk, the rest being in white. That the sampler was intended as a pattern is evident from some of the rows being unfinished. ”

“ YOUR SAMPLES.—Every Local Representative should start with at least four sample corsets to show, and should wear a Spirella Corset of the proper size and model for herself when taking orders. As fast as possible enlarge your line until you have a sample of every corset we are making. While we do not advise your carrying more than seven samples at a time, it is often valuable to have a sample of each style in your home so that you can study it and have it on hand when the occasion re­quires. ”

“ Spanish samplers are generally large; they are sometimes square, sometimes long in shape. They are as a rule entirely covered with border patterns, which in the square shape are worked along the four sides parallel to the edge; and which in the long shape runs in lines across the sampler, with a break in the middle, where the border changes to another pattern, thus giving the impression that the sampler is joined up the centre. The patterns of the borders vary a great deal; I have counted thirty different ones on one sampler. ”

“ It is rare to find later samplers without them, those of the eighteenth century containing assortments of every variety of lettering, Scottish ones especially laying themselves out for elaborately designed and florid alphabets. With the advent of the nineteenth century, however, the sampler began to lose its raison d’être, and quite one-half of those then made omit either the alphabet, or numerals, or both. ”

“ Of course I thought someone must have put down some nonsense or other, and Sampson had gone off to report him. All the same, I noticed that he hadn’t taken any of the papers with him when he ran out. Well, the top paper on the desk was written in red ink—which no one used—and it wasn’t in anyone’s hand who was in the class. They all looked at it—McLeod and all—and took their dying oaths that it wasn’t theirs. Then I thought of counting the bits of paper. And of this I made quite certain: that there were seventeen bits of paper on the desk, and sixteen boys in the form. ”