Measurement problems

The second example concerns a thickness measurement problem. Normally this is an easy task for ultrasonic testing However,... 

The required resolution for the powder coating thickness measurement problem is about 5 microns. Therefore a processing time unit of 0.08 ps (12.5 MHz) seemed to be ok (compare line 2 in table 1). First results based on real measurement are documented in Fig. 7. and are very promising result. Today corresponding patent is pending [7]. 

Sources of Error. pH electrodes are subject to fewer iaterfereaces and other types of error than most potentiometric ionic-activity sensors, ie, ion-selective electrodes (see Electro analytical techniques). However, pH electrodes must be used with an awareness of their particular response characteristics, as weU as the potential sources of error that may affect other components of the measurement system, especially the reference electrode. Several common causes of measurement problems are electrode iaterferences and/or fouling of the pH sensor, sample matrix effects, reference electrode iastabiHty, and improper caHbration of the measurement system (12). 

Not all elements of the industrial thermocouple need to be wine. For example, if a copper pipe contains a flowing fluid whose temperature is to be measured, a constantan wine attached to the pipe will form a T, or copper—constantan, thermocouple. Such arrangements ate difficult to caUbrate and requite full understanding of the possible inherent problems. For example, is the copper pipe fully annealed Homogeneous Pure, or an alloy Many ingenious solutions to specific measurement problems ate given in Reference 6. 

Here is a problems checklist for troubleshooting measurement Table 1 Common Measurement Problems ... 

To solve the measurement problem and obtain quantitative results (retardation, magnitude of the residual strain, etc.), various techniques are used. An example is using a very simple device known as a wedge compensator (ASTM D 4093). It is placed between the... 

The use of Equation (15.40) is limited to closed systems like that illustrated in Figure 15.10(a). Measurement problems arise whenever /), > 0 or Dgut > 0. See Figure 15.10(b) and suppose that an impulse is injected into the system at z = 0. If Din > 0, some of the tracer may enter the reactor, then diffuse backward up the inlet stream, and ultimately reenter. If Dgut > 0, some material leaving the reactor will diffuse back into the reactor to exit a second time. These molecules will be counted more than once by the tracer detection probes. The measured response function is not f t) but another function, g i), which has a larger mean ... 

BRM3 identified the need for producing different levels of an analyte in a given matrix (spiked standards) to address matrix related measurement problems in foods. 

Our current study of drug use and crime in arrestees in Manhattan overcame some of these measurement problems and enabled us to address some of these basic questions regarding POP use and crime. The recent use of PCP (as well as other drugs) in male arrestees was measured by a urinalysis of a specimen obtained within hours after arrest. We therefore did not have to rely on each person s accurate report that he had taken PCP. We shall use the urinalysis test results, with information from interviews with the arrestees, and from their criminal records, to describe the prevalence of PCP use in arrestees, the demographic characteristics of users and the types of offenses for which they are arrested. The next section describes our study of drug use and crime in arrestees in Manhattan. 

The analysis of the contribution made by increased pharmaceutical spending to the growth in the per capita intensity of health resources suffers from major measurement problems that deprive available indicators of any value. Traditional pharmaceutical price indexes (such as the Laspeyres index, used to calculate the pharmaceutical component of the consumer price index) provide little relevant information in a market in which the introduction of therapeutic innovations is of prime importance the indexes show an apparent freeze, and sometimes even a steep drop (as in the Spanish case). However, the steady rise in the average price per prescription paints a very different picture. 

Recognizing that any state Vi can show up in a measurement with the magnitude A allows the total measurement problem to be represented by the equation Av = Xv, where A is the same Hermitian matrix, i.e. 

The authors did not attempt to address this issue. Although construct validity is important, it does not guarantee taxometric validity, so both issues must be examined, especially in the case of null finding. For example, Franklin et al. could have performed a principal component analysis and examined loadings of the three indicators on the first unrotated component. As mentioned previously, these loadings can give a sense of indicator validity, and if the INTR failed to load sufficiently, this would indicate a measurement problem. 

Based on the observed problems in the measurement of safety in the chemical process industry, as outlined in the previous Chapter, additional research into this area is needed to provide companies with better indicators of possible accidents. In this Chapter the research methodology used to gain a more complete understanding of this measurement problem , is presented. This Chapter starts by discussing the focus, type and methodology of the research process. Then the research strategy and methods will be discussed to present the design structure of the complete research. 

With the exception of calibration, the measurement problems that were apparent in 1970, at the time of publication of the fost air quality criteria document on photochemical oxidants, have essentially been solved for ozone. This remarkable achievement is the result of unstinting efforts by people working at epa s National Environmental Research Center, North Carolina the National Bureau of Standards private research contractors sponsored primarily by epa private instrument manufacturers the Jet Propulsion Laboratory of the California Institute of Technology the Air and Industrial Hygiene Laboratory, California Department of Health the Air Pollution Research Center of the University of California at Riverside and the California Air Resources Board (carb). 

In practice, the application of x-ray measurement techniques to thin films involves some special problems. Typical films are much thinner than the penetration depth of commonly used x-rays, so the diffracted intensity is much lower than that from bulk materials. Thin films are often strongly textured this, on the other hand, results in improved intensity for suitable experimental conditions but complicates the measurement problem. Measurements at other than ambient temperature, not usually attempted with bulk materials, constitutes additional complexity. Since typical strains are on the order of 1 X 10 , measurements of interplanar spacing with a precision of the order of 1 X 10 are needed for reasonably accurate results hence, potential sources of error must be kept to a low level. In particular, the sample displacement error can be a major source of difficulty with a heated sample. The sample surface must remain accurately on the axis of the instrument during heating. 

There is a large number of certified reference materials available in the market. It is of highest importance to select an appropriate certified reference material for the intended use. There are a number of criteria, which can be used in order to select the appropriate certified reference material. Depending on the measurement problem the importance of each criterion can vary. Experience and continuous use of certified reference material help to make... 

Assistance in the identification of measurement problems Feedback and technical advice from organisers (reports, nevirsletters, open meetings)... 

Hanratty et al. s Solution to Recipe Item 1. Recipe item 1 will have a set of substeps that must be undertaken to find a solution to this measurement problem. They are ... 

Electromagnetic Compatibility (EMC). In-house and site testing services are available for EMC. The Spectrum Control, Inc is equipped for testing to MIL-STD-461, MIL-I-6iSI and similar RFI (Radio Frequency Interference) specs and also performs testing in accordance with.FCC (Federal Communications Commission) and HEW (Health, Education Welfare) requirements. The personnel are familiar with RADHAZ (Radiation Hazard) filter design and measurement problems... 

---