General Conversion Factors ASTM

Basic Standards for Chemical Technology. There are many numerical values that are standards ia chemical technology. A brief review of a few basic and general ones is given hereia. Numerical data and definitions quoted are taken from References 16—19 (see Units and conversion factors) and are expressed ia the International System of Units (SI). A comprehensive guide for the appHcation of SI has been pubUshed by ASTM (20). 

Besides the ASTM standard tests, a number of general reference books have been published on testing and on the mechanical properties of polymers and viscoelastic materials (2-7). Unfortunately, a great variety of units are used in reporting values of mechanical tests. Stresses, moduli of elasticity, and other properties are given in such units as MK.S (SI), cgs, and English units. A table of conversion factors is given in Appendix II. 

The ISA Standards and Practices Department is aware of the growing need for attention to the metric system of units in general, and the International System of Units (SI) in particular, in the preparation of instrumentation standards. The Department is further aware of the benefits to USA users of ISA standards of incorporating suitable references to the SI (and the metric system) in their business and professional dealings with other countries. Toward this end, this Department will endeavor to introduce Si-acceptable metric units in all new and revised standards, recommended practices, and technical reports to the greatest extent possible. Standard for Use of the International System of Units (SI) The Modern Metric System, published by the American Society for Testing Materials as lEEE/ASTM SI IQ-97, and future revisions, will be the reference guide for definitions, symbols, abbreviations, and conversion factors. 

Detailed directions for computing the viscosity index are published by the American Society for Testing and Materials [26]. For oils of viscosity not greater than 70 cs at 100 C and viscosity index not over 100 there is a table of values for L and H. For oils of viscosity greater than 70 cs at 100 C and for oils of viscosity index above 100, special computational formulas have been developed. These tables and formulas were adopted by ASTM in 1977. Prior to that the two fixed temperatures for the viscosity index were 100 and 210 F. Examination of Eqn 4-36 reveals that the value of the viscosity index does not depend on the units in which the viscosities are reported, since the factor for conversion to centistokes occurs in both the numerator and the denominator of the formula. The temperature interval and the viscosity-temperature characteristics of the series of reference oils are the two principal basic influences on the general nature of the viscosity index. 

Plastics - differential scanning calorimetry - general principles Determination of characteristic reaction cure temperatures and times, enthalpy of reaction and degree of conversion Glass-transition temperature and cure factor for laminates and printed circuit hoards Replaced hy ASTM D3418... 

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