Sampling costs

If the standard deviation of the lot caimot be estimated, a sampling program of greater sample size is required to generate an estimate of the standard deviation for future sampling operations. In some cases, sample size can be increased and sampling costs reduced by the use of automatic samplers. These offer a substantial reduction in labor costs but an increase in capital costs. 

Capital and operations and maintenance (O M) costs are different for leachate or groundwater treatment and depend on design flow of the system and level of treatment. Table 1 gives sample costs for leachate treatment, and Table 2 gives sample costs for groundwater. 

Detection by PCR can therefore be seen as having the advantages of high sensitivity and specificity, speed, and ability to assay many samples at the same time. Furthermore, the method does not require growth, nor an overly expensive apparatus. The requirement for competent technical assistance, the losses incurred from extraction and purification of samples, and per sample costs are among its disadvantages. 

The obsidian excavated from Trinidad de Nosotros demonstrates that obsidian trade during the Postclassic period was as complex as other periods. And, inland trade, as seen, through evidence of a trans-shipment port, was different than coastal trade. In addition to the cultural aspect of this study, we have demonstrated that it is possible to successfully use a field-portable XRF to correlate obsidian artifacts to their sources. Not only were sources identified, but the process was rapid (4-6 minutes per sample), cost-effective, and as accurate and precise as more traditional methods of analysis. Above all, and perhaps most importantly, when working with artifacts from museum collections and foreign countries, the process was non-destructive to the artifacts. 

Although the HPLC-MS method was demonstrated to be accurate and precise, as well as specific for I in plasma, the method was not amenable to low sample cost or rapidity of processing. For example, approximately two hours were required to process one sample at a cost of 80.00 per sample. These facts prompted a search for a more expedient and less expensive assay method. 

Limitations of the GMF are an additional aseptic subculture step, which increases the probability of adventitious contamination, and a proprietary membrane filter, which results in a per-sample cost currently exceeding 12 times that of the one-stage sieve, SAS, STA, SMA, and glass impinger systems, and four times that of the centrifugal sampler. 

Elemental analysis, determination of the chemical composition of material, is the most common type of analysis in archaeological chemistry. A variety of instruments can be used for such analyses including SEM microprobes, ICP spectrometers, mass spectrometers, CN analyzers, NAA analysis, and many others. The instruments chosen for elemental analysis depend on several factors including availability, elements of interest, the nature and size of sample, cost, turn-around time, and others. A variety of materials have been investigated with elemental analysis, almost any kind of archaeological material that exists. 

A set of default parameters must be estimated at the outset of operation to provide the client with cost of analytical procedures. A sample cost list for radioanalytical chemistry services is illustrated in Table 13.5. The earlier cost data are from a 1990 business plan developed by the authors and the 2004 cost data were extracted from cost proposals by a commercial laboratory. The magnitude of the cost for other analyses can be inferred from their similarity in processing to the cited methods. 

Figures 3.32 and 3.33 show the results of these approaches for the total test area These figures show that the pereentage of positives is hardly improved by taking three samples at one property, but that the percentage of false positives rises somewhat. Taking three samples in one property increases the sampling costs drastically.

A sample cost distribution shown in Table 4.21 for a typical heavy-duty maintenance job on a steel bridge structure shows that only a small portion of the total job cost is attributed to paint and its application (34). 

FIGURE 1. Distribution of total annual sample costs per instrument in West Germany (a), France (b), Belgium (c) and in The Netherlands (d). 

Moss, 1964). A two-pase system is used a solid phase consisting of the finely divided fluor and the liquid phase containing the radioactivity. This method is very useful in those cases where it is desired to recover the radioactive compound. In RIA, however, it is normally not necessary to recover the sample. Cost and voliame are the principal considerations. To date this method has not gained widespread use in RIA. 

Figure 1-1 Sample cost calculation worksheet. Adapted from OSHA web site, Cost Calculation Worksheet, Using the OSHA Safety Pays Advisor, http //www.osha-slc.gov/SLTC/safetyhealth ecat/mod1 estimating costs.htm, public domain [9],...

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