Introduction

Value-items in FESA properties should be labeld by their units. Units should be given as extra value-items with the suffix _units, e.g. a value item current should be accompanied by a value item current_units.

Units must be given as string, as identified in the following tables in the row Unit Name.

Common SI-Units

Quantity	Unit	SI-Units	Unit Name
length	meter		m
mass	kilogramm		kg
time	second		s
electrical current	ampere		A
temperature	kelvin		K
electrical charge	coulomb	A s	C
electrical voltage	voltage	W / A = m² kg / s³ A	V
magnetic field strength	tesla	Wb / m² = kg / s² A	T
frequency	hertz	1 / s	Hz
pressure	pascal	N / m² = kg / ms²	Pa

Convenience Units

Whenever possible, data should be labeled by SI base units, without prefixes like milli, micro, kilo (the base unit of the mass is kg), However, in some cases special units and specific naming would be very helpful:

• In some cases the data has no units but it would be helpfull to indicate the type of the quantity as 'unit name', E.g. in beam instrumentation, often pulses were counted (acquisition of the output singnal of a photomultiplier, acquisition of the output of a voltage to frequency converter, or other). When such result are presented directly, they should be labeled as counts.
• In some cases, equipment shows data on build-in displays in units other than SI base units. Converting data on the front-ends to SI base units would result in different values. As long as the difference is in the decimal power only this is no severe problem. But comparison of values would be made difficult when, e.g., one is displayed in minutes and the other in seconds. In such cases, the units of the equipment's diplays should be used in the FESA class too.

List shall be extended when quantities are used which are not listed.

Quantity	Comment	Unit Name
counts		cnt
counting rate		cnt/s
volume flux	if used on equipment display	cm^3/min

Commonly In-House Used Combined Units

List shall be extended when quantities are used which are not listed. Anyhow, most entries are expected to be used rarely on front-end systems.

Quantity	Units	Unit Name
magnetic rigidity	tesla * meter	Tm
dipole bending strength	tesla * meter	Tm
quadrupole focusing strength	tesla	T
magnetic field gradient	tesla / meter	T/m
electrical field gradient	volt / meter	V/m
magnetic ramp rate	tesla / second	T/s
electrical ramp rate	volt per second	V/s
frequency ramp rate	Hz per second	Hz/s
beam energy	electron volt	eV
beam energy per atomic mass unit	electron volt per mass unit	eV/u
velocity	meter per second	m/s
area	square meter	m^2
volume	cubic meter	m^3
flow	cubic meter per second	m^3/s

Other SI-Units

Not expected to be used in properties of front-end Systems. If so, entry should be moved to upper most table.

Quantity	Unit	SI-Units	Unit Name
amount of substance	mole			mol
luminous intensity	candela			cd
angle	radian	1		rad
solid angle	steradian	1		sr
force, weight	newton	kg m / s²		N
energy, work	joule	N m = m² kg / s²		J
power	watt	J / s = m² kg / s³		W
electrical capacity	farad	C / V		F
elektrical resistance	ohm	V / A = m² kg / s³ A²	Ω	Ohm
elektrical conductance	siemens	1 / Ω = s³ A²/ m² kg		S
magnetical flux	weber	V s = m² kg / s² A		Wb
inductance	henry	Wb / A = m² kg / s² A²		H
temperature Celsius	degree Celsius	K	ºC	degC
luminance	lux	lm / m² = cd / m²		lx
redioactivity	becquerel	1 / s		Bq
absorbed dose	gray	J / kg = m² / s²		Gy
equivalent dose	sievert	J / kg = m² / s²		Sv
katalytic activity	katal	mol / s		kat