Testing and measurement

The radiation and temperature dependent mechanical properties of viscoelastic materials (modulus and loss) are of great interest throughout the plastics, polymer, and rubber from initial design to routine production. There are a number of laboratory research instruments are available to determine these properties. All these hardness tests conducted on polymeric materials involve the penetration of the sample under consideration by loaded spheres or other geometric shapes [1]. Most of these tests are to some extent arbitrary because the penetration of an indenter into viscoelastic material increases with time. For example, standard durometer test (the "Shore A") is widely used to measure the static "hardness" or resistance to indentation. However, it does not measure basic material properties, and its results depend on the specimen geometry (it is difficult to make available the identity of the initial position of the devices on cylinder or spherical surfaces while measuring) and test conditions, and some arbitrary time must be selected to compare different materials. 

Many of the most relevant projects under Brite-EuRam, plus some from "Standards, Measurements and Testing" (SMT), Esprit IlM, and the "Nuclear Fission Programme", have now been grouped in the network, with the participating projects clustered under the following main topics, under which a number of specific cluster activities have been defined ... 

Scientific Apparatus Makers Association 1140 Coimecticut Avenue, NW Washington, D.C. 20036 Standards for analytical instmments, laboratory apparatus, measurement and test instmments, nuclear instmments, optical instmments, process measurement and control, and scientific laboratory furniture and equipment (see Analytical methods). 

Calibrating inspection, measuring, and test equipment (clause 4.11.2)... 

The standard requires the results of process studies to be documented with specifications for means of production, measurement and test, and maintenance instructions. 

Procedures are required for the control and maintenance of inspection, measuring, and test equipment and to cover test software, not only for calibration. This section of the standard is often referred to as the calibration requirement but it goes far beyond mere calibration. In assessing compliance with section 4.11, there are at least 30 requirements to check (see the questionnaire at the end of this chapter) and calibration is only one of them. Figure 11.2 shows the processes needed to control, calibrate, and maintain inspection, measuring, and test equipment. The shaded boxes indicate interfaces with other processes. 

The standard requires appropriate statistical studies to be conducted to anal /ze the variation present in the results of each type of measuring and test equipment system. 

The standard requires the supplier to calibrate and adjust all inspection, measuring, and test equipment including measurement devices at prescribed intervals, or prior to use, against certified equipment having a known valid relationship to nationally recognized standards. 

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