Conversion Factors for Non-SI Units

Many non-Sl units are now defined exactly in terms of SI some can only be related to SI units via fundamental constants, and the relationship is therefore restricted by the precision to which the constants are known. Factors for converting some non-Sl units into their SI equivalents are listed in  

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This edition of the Regulations for the Safe Transport of Radioactive Material uses the International System of Units (SI). The conversion factors for non-SI units are ... 

A number of non-SI units are commonly used in the literature of quantum chemistry. We therefore provide appropriate conversion factors for certain specialized units used in this chapter ... 

Conversion Factors for UK Imperial Units and Other Non-SI Units OF Measurement... 

Table 1.1 Energy Conversion Factors between Non-SI (Traditional) and SI Units for the BDEs...

The use of non-SI units is strongly discouraged. For these units there often do not exist standards, and for historical reasons the same denomination may mean sundry units. For example, it is common practice in theoretical chemistry to state energy values in kilocalories. However, to convert a calorie to the SI unit Joule, there exist different conversion factors ... 

Table 1.3 gives some commonly used non-SI units for certain quantities, together with conversion factors relating them to SI units. We use these in some examples and problems, except for the calorie unit of energy. This last, however, is frequently encountered. 

Table A1.3 Non-SI units and their factors for conversion to the SI system...

Although SI is the internationally accepted system of measurement in science, other units are encountered. Useful conversion factors are found in Table 1-4. For example, common non-SI units for energy are the calorie (cal) and the Calorie (with a capital C, which stands for 1 000 calories, or 1 kcal). Table 1-4 states that 1 cal is exactly 4.184 J (joules). 

Environmental Protection Agency policy is to express all measurements in SI units. When implementing this practice will result in undue costs or lack of clarity, conversion factors are provided for the non-SI units. This report uses British Engineering units of measure for some cases. For conversion to the SI system, use the following conversions ... 

Section 7.1 gives examples illustrating the use of quantity calculus for converting the values of physical quantities between different units. The table in section 7.2 lists a variety of non-SI units used in chemistry, with the conversion factors to the corresponding SI units. Conversion factors for energy and energy-related units (wavenumber, frequency, temperature and molar energy), and for pressure units, are also presented in tables inside the back cover. 

Thermodynamic data are given according to the Systeme International d unites (SI units). The unit of energy is the joule. Some basic conversion factors, also for non-thermodynamic units, are given in Table II-4. 

The following table gives conversion factors from various units of measure to SI units. It is reproduced from NIST Special Publication 811, Guide for the Use of the International System of Units (SI). The table gives the factor by which a quantity expressed in a non-SI unit should be multiplied in order to calculate its value in the SI. The SI values are expressed in terms of the base, supplementary, and derived units of SI in order to provide a coherent presentation of the conversion factors and facilitate computations (see the table International System of Units in this section). If desired, powers of ten can be avoided by using SI prefixes and shifting the decimal point if necessary. 

These relations are listed in Table 4.1 together with the conversion factors for some non-SI units still commonly in use. 

Eq. (2) for the gas phase, but with its chemical potential p,° defined at atmospheric pressure p = 1.0 atm. Equation (3) expresses then the chemical potential of the (pure) solvent vapor over the solution. Note, that in these expressions one always uses atm as unit of pressure, a non-SI unit of pressure (see Fig. 2.3, for conversion factors see Sect 4.5.1). At equilibrium, the two logarithmic terms in Eqs. (1) and (3) must be equal, Pi = pP, and produce Raoult s law. Raoult s law is indicated by the diagonal in the graph of Fig. 7.3. At concentrations approaching the pure solvent, Xj - 1.0, this equation must always hold. 

It is often necessary to convert the adopted value of a fundamental constant to another (SI or non-SI) unit. Useful conversion factors for energy equivalent quantities can be derived using the following relations ... 

In this book the only units of measure used for describing physical quantities and properties of materials are those recommended by the Systhme International d Unitis (SI). For accurate conversion factors between these units and the other non-SI units (e.g., cgs, fps. Imperial, and US customary), please refer to the reference book by the same author ... 

The Si units are listed immediately after the quantity in this case Length m/X. The m stands for meter, and the X designates the non-Si units for the same quantity. These non-Si units follow the numerical conversion factors. 

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