# Auxiliary unit of measure

An auxiliary unit (also pseudo unit , pseudo unit , Pseudomaß or rarely clue word is) a name or character in the manner of a unit for quantities of dimension number is used.

Auxiliary units of measurement are used for clarification in certain contexts and for easier handling of numerical values, although the respective size could also be described by a pure, unnamed number.

## Units of measure and counting measures

Special units of measure
• mol (mol) - Amount of substance in chemistry: 1 mol ≈ 6.022 · 10 23 particles
• Einstein (E) - number of light quanta / photons, 1 E = 1 mol
Piece dimensions
• Piece (pieces) in logistics
special higher units:
• Dozen (Dzd., 1 dozen = 12)
• Shock (obsolete, 1 shock = 5 dozen = 60)
• Gros (outdated, 1 Gros = 12 dozen = 144)
• Large size (outdated, 1 large size = 12 large size = 1728)
Counting measures for people
• Person (pers.) I. A.
• Head , for example in business statistics
• Inhabitants (EW), official statistics
• Man , especially military
• Pax (auxiliary unit) , unit of measurement for passengers (ICAO code), guests, event visitors in estimated / rounded numbers
Counting measures for paper

## Units for quotients of similar sizes

### Linear

Amount / amount
Length / length (plane angle)
• Radians (1 rad = 1 m / 1 m = 1)
• Degrees (1 ° = π / 180 1 rad)
• Gon (gon, 1 gon = π / 200 1 rad)
• Dash (¯, mil, A ‰; 1¯ = 2π / 6400 rad)
Surface / surface (solid angle)
• Steradian (1 sr = 1 m² / 1 m² = 1)
• Square degree ((°) ², obsolete, 1 (°) ² = ( 2/360) ² sr)${\ displaystyle \ pi}$
Time Time
Other

### Logarithmic

In the following cases, the auxiliary unit of measurement indicates that the size value of the size has been divided by an agreed size value and the result logarithmized . The "agreed size value" and the base of the logarithm must be evident, and therefore indicated if necessary; they are often already clear from the context, for example if they are based on DIN standards.

• Magnitude (mag)
• Neper (1 Np = ln e = 1), among other things for the specification of levels in the acoustics
• Bel (B) or decibel (1 dB ≈ 0.1151293 Np), among other things for the specification of levels in acoustics and communication technology
Acoustics
• Phon (phon) for the volume
• Sone (sone) for loudness
• Bark (Bark) for the perceived pitch
• Mel (mel) for the perceived pitch
• Cent (Cent, C) for intervals
• Octave (O) for intervals
Other
• Shannon (Sh) (informational content)
• Ban , out of date (informational content)
• Nit (nit), out of date (information content)

## additional

In the case of physical quantities , one must always pay attention to the separation of the quantity value (unit) and additional information . However, especially in the case of auxiliary units of measurement, mixtures, e.g. Sometimes even by specifying a DIN standard, in use, for example “dB (C)” (here the “C” is an indication of the measurement method according to which the level measure is determined, which is specified with the aid of the auxiliary unit of measurement decibel ).

## Individual evidence

1. a b DIN EN ISO 80000-1: 2013-08 Sizes and units - general .
2. DIN EN ISO 80000-11: 2013-08 Sizes and units - parameters of the dimension number .
3. a b DIN 1301-1 units: unit names, unit symbols , as "derived SI unit"; DIN EN ISO 80000-3 sizes and units - space and time .
4. a b DIN 1301-1 units: unit names, unit symbols , as "unit outside the SI"; DIN EN ISO 80000-3 sizes and units - space and time .
5. a b DIN EN 60027-3; Formula symbols for electrical engineering: Logarithmic and related quantities and their units .
6. DIN 45630-1; Basics of sound measurement; Physical and subjective quantities of sound .
7. DIN 13320; Product image - acoustics; Spectra and transfer curves, terms, representation .