Mechanical standards vibration measurements

ISO 5349-1, Mechanical Vibration—Measurement arul Evaluation cf Human Exposure to Hand-Transmitted Vibration—Part I General Guidelines, International Organization for Standardization, Geneva, 2001. 

ISO 5349, Mechanical Vibration Measurement and Assessment of Human Exposure to Hand-Transmitted Vibration, International Standards Organization, Geneva. ISO 2631, Guide for the Evaluation of Human Exposure to Whole-Body Vibration, ISO, Geneva. 

Dynamic techniques are used to determine storage and loss moduli, G and G respectively, and the loss tangent, tan 5. Some instmments are sensitive enough for the study of Hquids and can be used to measure the dynamic viscosity T 7 Measurements are made as a function of temperature, time, or frequency, and results can be used to determine transitions and chemical reactions as well as the properties noted above. Dynamic mechanical techniques for sohds can be grouped into three main areas free vibration, resonance-forced vibrations, and nonresonance-forced vibrations. Dynamic techniques have been described in detail (242,251,255,266,269—279). A number of instmments are Hsted in Table 8. Related ASTM standards are Hsted in Table 9. 

A new commercially available cation membrane, Nepton CR-61 on 4-ounce dynel backing, is 23 mils thick and has an electrical through resistance in 0.01A NaCl of 14 ohms per sq. cm., about two thirds that of a similar membrane 30 mils thick on 9-ounce dynel backing. It has the same electrical resistance as a 9-ounce glass-backed CR-61 membrane, also 30 mils thick, but much better chemical stability to acids and alkalies and better mechanical stability to vibrations. The Mullen burst strength of the 4-ounce membranes is 140 p.s.i., about half that for the 9-ounce dynel, but still sufficient to be useful for field operation. Its stiffness and resistance to bowing, for which no standard measurements are yet available, are sufficient to allow its use in membrane stacks with tortuous path spacers operating at pressures of 60 p.s.i. and flow velocities of 60 cm. per second. 

System automation is made easier by the availability of many subsystems that are easily controlled by computer. Process instrumentation of all types and radiometric measurement equipment is available with standard computer interface options. Computer hardware and software is available both for simple and complex control systems. Mechanical equipment for automating the handling of multiple samples includes pumps, valves, heaters, shakers, vibrating plates, and stirring systems for mixing samples. 

ISO 10819, Mechanical Vibration and Shock—Hand-Arm Vibration—Method for the Measurement and Evaluation of the Vibration Transmissibility of Gloves at the Palm of the Hand, International Organization for Standardization, Geneva, 1997. 

ISO/FDIS 13091-2, Mechanical Vibration—Vibrotactlle Perception Thresholds for the Assessment of Nerve Dysfunction—Part 2 Analysis and Interpretation of Measurements at the Fingertips, International Organization for Standardization, Geneva, 2002. 

Accelerometers measure vibration and acceleration. ISO standards on mechanical vibration and shock offer measurement recommendations. A reference on instrumentation for acceleration and vibration will help in establishing measurements. 

ISO 5349 (1986) Mechanical vibration - guidelines for the measurement and the assessment of human exposure to hand-transmitted vibration. International Organization for Standardization... 

International Standard ISO 2373 Mechanical Vibration of Certain Rotating Electrical Machinery with Shaft Heights between 80 and 400 mm—Measurement and Evaluation of Vibration Severity, ... 

Dynamic viscoelastic measurements are useful in studying the structure of polymers, because these mechanical properties are sensitive to glass transition, crystallinity, cross-linking, filling systems (filler or plasticizer), molecular aggregation, and phase separation. To determine dynamic viscoelastic properties, such as storage modulus, loss modulus, and tan, various methods have been proposed, and recently many types of instruments are commercially available. Typical methods to measure the dynamic viscoelasticity are classified into three categories damped free vibration, resonance free vibration, and nonresonance forced vibration. These methods are standardized by the international standard ISO 6721 [3]. 

The International Organization for Standardization (ISO) standard 2631-1, Mechanical Vibration and Shock Evaluation of Human Exposure to Whole-Body Vibration Part I General Requirements , specify how to measure and analyze WBV. Action limits and exposure limits values are presented in Table 1 (Lewis Johnson, 2012). To further evaluate transient shock vibration exposures in relation to human health, the International Organization for Standardization (ISO) published a new WBV standard, ISO 2631-5, in 2004. Long-term... 

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