The reference value is in many fields of a particular numerical value which to compare is used.
For example, all information in percent is based on a reference value. If this is not specified, misunderstandings or contradictions can easily arise. If 20% of the population of a country is affected by poverty , the population (total population) is the reference value:
The comparison value is the number of people affected by poverty, the reference value is the total population, the percentage is called the poverty rate .
Use in physics and technology
In the physical-technical context, the following uses are highlighted in the specialist literature :
- In measurement technology as well as in quality assurance and statistics, the reference value is a clearly defined value to which reference is made to define a result deviation ( measurement deviation ). The reference value can be, for example, the upper limit of a measuring range , the scale length or any other clearly defined value. In particular, depending on the definition or agreement, it can be the true , correct or expected value .
- Furthermore, in measurement technology, a measurement can be viewed as a comparison with a reference value, the associated unit of measurement being used as the reference value .
- A reference value is always required for logarithmic quantities , a power quantity or a power root quantity being related to a variable or fixed value before the logarithm is formed, for example in the case of the voltage level . The definition of the fixed size is arbitrary for each application. In audio technology in particular, various reference values are standardized for clear understanding , see reference value (acoustics) .
- On closer inspection, many material constants turn out to be dependent on influencing variables . Then they are given at a fixed reference value. As far as deviations of the constants can be indicated, these are determined from the reference value. Example: Influence of temperature of the specific resistance .
The variable to be compared is often related to the reference value via a difference (e.g. for the measurement deviation), but the values can also be linked via a quotient (e.g. for the ratio) or a quotient of the difference to the Reference value (e.g. for the relative error limit ).
Further subject-specific uses
In various specialist fields, the term reference value, possibly also called reference value, is defined in a special way, or it is replaced by a whole reference system of many individual reference values.
Such reference values can be:
- in medicine : reference values for body functions and chemical-biological analyzes - as an orientation as to whether measured values are to be regarded as pathological;
- in banking : the base value , the key rate , the reference rate or the base rate ;
- in geodesy the "mean earth figure 1980" in the form of the reference system GRS80 ;
- In astronomy , the classic polar star was 2.1 mag, the photometric zero point of the apparent brightness.
- ↑ IEC 60050, see DKE German Commission for Electrical, Electronic and Information Technologies in DIN and VDE: International Electrotechnical Dictionary IEV entry 311-01-16.
- ↑ Martin Klein (Ed.): Introduction to the DIN standards. Springer Fachmedien, 12th edition, 1997, p. 788
- ↑ DIN 55350-13, Terms of Quality Assurance and Statistics - Part 13: Terms for the Accuracy of Determination Procedures and Determination Results , 1987, No. 1.2
- ↑ Sigmar German, Peter Drath: Manual SI Units: Definition, Realization, Preservation and Distribution of SI Units, Fundamentals of Precision Metrology , Vieweg, 1979, p. 257
- ↑ Herbert Bernstein: LF and HF measurement technology: measuring with oscilloscopes, network analyzers and spectrum analyzers. , Springer Vieweg, 2015, p. 265
- ↑ Erwin Meyer, Dieter Guicking: Schwingungslehre. Vieweg. 1974, p. 19
- ^ Karl-Heinrich Grote, Jörg Feldhusen (Hrsg.): Dubbel: Pocket book for mechanical engineering. Springer, 23rd edition, 2011, p. 29
- ↑ Horst Germer, Norbert Wefers: measuring electronics: Volume 1 , Hüthig, 1985, p. 41