What are the Numeric search optional units?

Last updated on September 24, 2025

Compendex and Inspec records contain standardized numeric quantities and ranges. This normalized format of numeric data improves numeric search functionality in Engineering Village.

All 62 numeric fields have one default unit of measure. Additionally, some of these fields have one or more optional units of measure that can be used for numeric searching.

Use the Expert search form to perform specific numeric searches using optional or default units of measure in Compendex and Inspec.

You may refine your numeric search results using the Numeric filter feature on the Quick and Expert search result pages. The Numeric filter is an easy way to construct a numeric search that does not require the use of field names and Boolean logic. All the optional and default units listed in the Numeric filter are contained in the chart below. All numeric units are available in both Expert search and via the Numeric filter.

Conduct numeric search using optional units of measure

Below are the field names, applicable databases, optional units, default units, and descriptions for each of the 62 numerically indexed fields. Refer also to the Numeric fields chart for the default units for each of these fields.

Refer to the Numeric search queries FAQ for detailed instructions regarding the search syntax to run a numeric search query using optional units on the Expert search page in Compendex and Inspec.

Field Names

Databases

Description
(* denotes default unit)

Optional Unit(s)
(case sensitive)

NU_ABSORBED_DOSE

Compendex and Inspec

centigray

cGy

 

 

*gray

Gy

 

 

kilogray

kGy

 

 

kilorad

krad

 

 

megagray

MGy

 

 

microgray

muGy

 

 

milligray

mGy

 

 

millirad

Mrad

 

 

nanogray

nGy

NU_ACCELERATION

Compendex

centimeter per second squared

cm/s2

 

 

feet per second squared

ft/s2

 

 

inch per second squared

in/s2

 

 

kilometer per hour squared

km/hr2

 

 

kilometer per second squared

km/s2

 

 

*meter per second squared

m/s2

 

 

micrometer per second squared

mum/s2

 

 

millimeter per second squared

mm/s2

NU_AGE

Compendex and Inspec

billion year

Ga

 

 

day

day

 

 

million year

Ma

 

 

month

month

 

 

thousand year

ka

 

 

week

week

 

 

*year

yr

NU_AMOUNT_OF_SUBSTANCE

Compendex

centimole

cmol

 

 

kilomole

kmol

 

 

micromole

mumol

 

 

millimole

mmol

 

 

*mole

mol

 

 

nanomole

nmol

 

 

picomole

pmol

NU_ANGULAR_VELOCITY

Compendex

degree per hour

deg/hr

 

 

degree per minute

deg/min

 

 

degree per second

deg/s

 

 

*radian per second

rad/s

NU_APPARENT_POWER

Compendex and Inspec

kilovolt ampere

kVA

 

 

megavolt ampere

MVA

 

 

*volt ampere

VA

NU_AREA

Compendex

acre

acre

 

 

square centimeter

cm2

 

 

square foot

ft2

 

 

hectare

hectare

 

 

square inch

in2

 

 

square kilometer

km2

 

 

*square meter

m2

 

 

square micrometer

mum2

 

 

square mile

mi2

 

 

square millimeter

mm2

 

 

square nanometer

nm2

 

 

square picometer

pm2

 

 

square yard

yd2

NU_BIT_RATE

Compendex and Inspec

*bits per second

bit/s

 

 

gigabits per second

Gbit/s

 

 

kilobits per second

kbit/s

 

 

megabits per second

Mbit/s

 

 

terabits per second

Tbit/s

NU_CAPACITANCE

Compendex and Inspec

*farad

F

 

 

microfarad

muF

 

 

millifarad

mF

 

 

nanofarad

nf

 

 

picofarad

pf

NU_CURRENT_DENSITY

Compendex

ampere per square centimeter

A/cm2

 

 

*ampere per square meter

A/m2

 

 

milliampere per square centimeter

mA/cm2

 

 

nanoampere per square centimeter

nA/cm2

NU_DECIBEL

Compendex

*decibel

dB

NU_DECIBEL_ISOTROPIC

Compendex

*decibel isotropic

dBi

NU_DECIBEL_MILLIWATTS

Compendex

*decibel milliwatt

dBm

NU_ELECTRIC_CURRENT

Compendex and Inspec

*ampere

A

 

 

gigaampere

GA

 

 

kiloampere

kA

 

 

megaampere

MA

 

 

microampere

muA

 

 

milliampere

mA

 

 

nanoampere

nA

 

 

picoampere

pA

 

 

teraampere

TA

NU_ELECTRIC_FIELD_STRENGTH

Compendex

kilovolt per centimeter

kV/cm

 

 

kilovolt per meter

kV/m

 

 

millivolt per centimeter

mV/cm

 

 

volt per centimeter

V/cm

 

 

*volt per meter

V/m

 

 

volt per micrometer

V/mum

NU_ELECTRICAL_CONDUCTANCE

Compendex and Inspec

microsiemen

muS

 

 

millisiemen

mS

 

 

nanosiemen

nS

 

 

*siemen

S

NU_ELECTRICAL_CONDUCTIVITY

Compendex and Inspec

microsiemen per centimeter

muS/cm

 

 

millisiemen per centimeter

mS/cm

 

 

millisiemen per millimeter

mS/mm

 

 

siemen per centimeter

S/cm

 

 

*siemen per meter

S/m

 

 

siemen per millimeter

S/mm

NU_ELECTRICAL_RESISTANCE

Compendex and Inspec

kiloohm

kOhm

 

 

megaohm

MOhm

 

 

microohm

muOhm

 

 

milliohm

mOhm

 

 

nanoohm

nOhm

 

 

*ohm

Ohm

 

 

picoohm

pOhm

NU_ELECTRICAL_RESISTIVITY

Compendex and Inspec

microohm centimeter

muOhm.cm

 

 

microohm meter

muOhm.m

 

 

milliohm centimeter

mOhm.cm

 

 

milliohm meter

mOhm.m

 

 

ohm centimeter

Ohm.cm

 

 

*ohm meter

Ohm.m

 

 

ohm millimeter

Ohm.mm

NU_ELECTRON_VOLT

Compendex and Inspec

*electron volt

eV

 

 

exaelectron volt

EeV

 

 

gigaelectron volt

GeV

 

 

kiloelectron volt

keV

 

 

megaelectron volt

MeV

 

 

microelectron volt

mueV

 

 

millielectron volt

meV

 

 

nanoelectron volt

neV

 

 

petaelectron volt

PeV

 

 

teraelectron volt

TeV

NU_ENERGY

Compendex and Inspec

gigajoule

GJ

 

 

*joule

J

 

 

kilojoule

kJ

 

 

megajoule

MJ

 

 

microjoule

muJ

 

 

millijoule

mJ

 

 

nanojoule

nJ

 

 

picojoule

pJ

 

 

terajoule

TJ

NU_EQUIVALENT_DOSE

Compendex and Inspec

*sievert

Sv

 

 

millisievert

mSv

NU_FORCE

Compendex

kilogram force

kgf

 

 

kilonewton

kN

 

 

meganewton

MN

 

 

micronewton

muN

 

 

millinewton

mN

 

 

nanonewton

nN

 

 

*newton

N

NU_FREQUENCY

Compendex and Inspec

gigahertz

GHz

 

 

*hertz

Hz

 

 

kilohertz

kHz

 

 

megahertz

MHz

 

 

microhertz

muHz

 

 

millihertz

mHz

 

 

nanohertz

nHz

 

 

picohertz

pHz

 

 

terahertz

THz

NU_ILLUMINANCE

Compendex

lumen per square centimeter

lm/cm2

 

 

lumen per square millimeter

lm/mm2

 

 

*lux

lx

NU_INDUCTANCE

Compendex

*henry

H

 

 

microhenry

muH

 

 

millihenry

mH

 

 

nanohenry

nH

NU_LINEAR_DENSITY

Compendex

gram per centimeter

g/cm

 

 

gram per meter

g/m

 

 

gram per millimeter

g/mm

 

 

kilogram per centimeter

kg/cm

 

 

*kilogram per meter

kg/m

 

 

kilogram per millimeter

kg/mm

 

 

microgram per centimeter

mug/cm

 

 

milligram per centimeter

mg/cm

NU_LUMINANCE

Compendex

candela per square centimeter

cd/cm2

 

 

*candela per square meter

cd/m2

 

 

candela per square millimeter

cd/mm2

NU_LUMINOUS_EFFICACY

Compendex

*lumen per watt

lm/W

NU_LUMINOUS_EFFICIENCY

Compendex

*candela per ampere

cd/A

NU_LUMINOUS_FLUX

Compendex

*lumen

lm

NU_MAGNETIC_FIELD_STRENGTH

Compendex

ampere per centimeter

A/cm

 

 

*ampere per meter

A/m

 

 

ampere per millimeter

A/mm

 

 

kiloampere per meter

kA/m

 

 

microampere per centimeter

muA/cm

 

 

microampere per micrometer

muA/mum

 

 

microampere per millimeter

muA/mm

 

 

milliampere per centimeter

mA/cm

 

 

milliampere per millimeter

mA/mm

 

 

nanoampere per micrometer

nA/mum

 

 

picoampere per micrometer

pA/mum

NU_MAGNETIC_FLUX_DENSITY

Compendex and Inspec

microtesla

muT

 

 

millitesla

mT

 

 

nanotesla

nT

 

 

*tesla

T

NU_MASS

Compendex and Inspec

gram

g

 

 

*kilogram

kg

 

 

megagram

tons

 

 

microgram

mug

 

 

milligram

mg

 

 

nanogram

ng

 

 

ounce

oz

 

 

picogram

pg

 

 

pound

lb

NU_MASS_DENSITY

Compendex

gram per cubic centimeter

g/cm3

 

 

gram per liter

g/l

 

 

gram per milliliter

g/ml

 

 

*kilograms per cubic meter

kg/m3

 

 

microgram per liter

mug/l

 

 

microgram per milliliter

mug/mL

 

 

milligram/milliliter

mg/mL

 

 

milligram/milliliter

mg/mL

 

 

nanogram/milliliter

ng/mL

NU_MASS_FLOW_RATE

Compendex

gram per minute

g/min

 

 

gram per second

g/s

 

 

kilogram per hour

kg/hr

 

 

kilogram per minute

kg/min

 

 

*kilogram per second

kg/s

 

 

milligram per second

mg/s

 

 

pound per hour

lb/hr

 

 

tonne per day

tons/day

 

 

tonne per year

tons/yr

NU_MOLALITY

Compendex

micromole per gram

mumol/g

 

 

millimole per gram

mmol/g

 

 

millimole per kilogram

mmol/kg

 

 

mole/gram

mol/g

 

 

*mol per kilogram

mol/kg

NU_MOLAR_CONCENTRATION

Compendex

killimole per cubic meter

kmol/m3

 

 

micromole per liter

mumol/L

 

 

millimole per liter

mmol/L

 

 

millimole per cubic meter

mmol/m3

 

 

mole per cubic centimeter

mol/cm3

 

 

mole per cubic decimeter

mol/dm3

 

 

mole per liter

mol/L

 

 

*mole per cubic meter

mol/m3

NU_MOLAR_MASS

Compendex

*gram per mol

g/mol

NU_PERCENTAGE

Compendex

*percent

%

NU_POWER

Compendex and Inspec

gigawatt

GW

 

 

kilowatt

kW

 

 

megawatt

MW

 

 

microwatt

muW

 

 

milliwatt

mW

 

 

nanowatt

nW

 

 

picowatt

pW

 

 

terawatt

TW

 

 

*watt

W

NU_PRESSURE

Compendex and Inspec

atmosphere

atm

 

 

bar

bar

 

 

gigapascal

GPa

 

 

hectopascal

hPa

 

 

kilobar

kbar

 

 

kilopascal

kPa

 

 

megapascal

MPa

 

 

millibar

mbar

 

 

millimeter mercury

mmHg

 

 

millipascal

mPa

 

 

millitorr

mTorr

 

 

*pascal

Pa

 

 

terapascal

TPa

 

 

torr

Torr

NU_RADIATION_EXPOSURE

Compendex and Inspec

*coulomb per kilogram

C/kg

 

 

microcoulomb per kilogram

muC/kg

 

 

microroentgen

muR

 

 

millicoulomb per kilogram

mC/kg

 

 

milliroentgen

mR

NU_RADIO_ACTIVITY

Compendex and Inspec

*becquerel

Bq

 

 

curie

Ci

 

 

gigabecquerel

GBq

 

 

kilobecquerel

kBq

 

 

megabecquerel

MBq

 

 

microcurie

muCi

 

 

millibecquerel

mBq

 

 

millicurie

mCi

 

 

petabecquerel

PBq

 

 

terabecquerel

TBq

NU_ROTATIONAL_SPEED

Compendex

kilorevolution per minute

krpm

 

 

*revolution per minute

rpm

NU_SIZE

Compendex and Inspec

centimeter

cm

 

 

foot

ft

 

 

inch

in

 

 

kilometer

km

 

 

*meter

m

 

 

micrometer

mum

 

 

mile

miles

 

 

millimeter

mm

 

 

nanometer

nm

 

 

picometer

pm

 

 

yard

yd

NU_SPECIFIC_ENERGY

Compendex

calorie per gram

cal/g

 

 

calorie per kilogram

cal/kg

 

 

joule per gram

J/g

 

 

*joule per kilogram

J/kg

 

 

kilocalorie per gram

kcal/g

 

 

kilocalorie per kilogram

kcal/kg

 

 

kilojoule per gram

kJ/g

 

 

kilojoule per kilogram

kJ/kg

NU_SPECIFIC_SURFACE_AREA

Compendex

square centimeter per gram

cm2/g

 

 

square meter per gram

m2/g

 

 

*square meter per kilogram

m2/Kg

NU_SPECIFIC_VOLUME

Compendex

cubic centimeters per gram

cm3/g

 

 

liter per gram

L/g

 

 

liter per kilogram

L/kg

 

 

cubic meters per gram

m3/g

 

 

*cubic meters per kilogram

m3/kg

 

 

milliliter per gram

mL/g

 

 

milliliter per kilogram

mL/kg

NU_SPECTRAL_EFFICIENCY

Compendex

*bit per second hertz

bit/s/Hz

 

 

gigabit per second hertz

Gbit/s/Hz

 

 

kilobit per second hertz

kbit/s/Hz

 

 

megabit per second hertz

Mbit/s/Hz

 

 

terabit per second hertz

Tbit/s/Hz

NU_SURFACE_CHARGE_DENSITY

Compendex

coulomb per centimeter squared

C/cm2

 

 

*coulomb per square meter

C/m2

 

 

microcoulomb per square centimeter

muC/cm2

 

 

microcoulomb per square meter

muC/m2

 

 

millicoulomb per square centimeter

mC/cm2

 

 

millicoulomb per square meter

mC/m2

NU_SURFACE_DENSITY

Compendex

gram per square centimeter

g/cm2

 

 

gram per square meter

g/m2

 

 

kilogram per square centimeter

kg/cm2

 

 

*kilogram per square meter

kg/m2

 

 

kilogram per square millimeter

kg/mm2

 

 

microgram per square centimeter

mug/cm2

 

 

milligram per square centimeter

mg/cm2

 

 

milligram per square meter

mg/m2

NU_SURFACE_POWER_DENSITY

Compendex

gigawatt per square centimeter

GW/cm2

 

 

kilowatt per square centimeter

kW/cm2

 

 

kilowatt per square meter

kW/m2

 

 

megawatt per square meter

MW/m2

 

 

microwatt per square centimeter

muW/cm2

 

 

milliwatt per square centimeter

mW/cm2

 

 

milliwatt per square meter

mW/m2

 

 

watt per square centimeter

W/cm2

 

 

*watt per square meter

W/m2

NU_SURFACE_TENSION

Compendex

kilonewton per meter

kN/m

 

 

millinewton per meter

mN/m

 

 

newton per centimeter

N/cm

 

 

*newton per meter

N/m

 

 

newton per millimeter

N/mm

NU_TEMPERATURE

Compendex and Inspec

celsius

C

 

 

fahrenheit

F

 

 

*kelvin

K

NU_THERMAL_CONDUCTIVITY

Compendex

microwatt per meter kelvin

muW/mk

 

 

milliwatt per meter kelvin

mW/mk

 

 

*watt per meter kelvin

W/mk

NU_TIME

Compendex and Inspec

femtosecond

fs

 

 

hour

hr

 

 

microsecond

mus

 

 

millisecond

ms

 

 

minute

min

 

 

nanosecond

ns

 

 

picosecond

ps

 

 

*second

s

NU_TORQUE

Compendex

kilonewton meter

kN.m

 

 

millinewton meter

mN.m

 

 

newton centimeter

N.cm

 

 

*newton meter

N.m

 

 

pound foot

lb.ft

NU_VELOCITY

Compendex and Inspec

centimeter per second

cm/s

 

 

foot per second

ft/s

 

 

inch per second

in/s

 

 

kilometer per hour

km/hr

 

 

kilometer per second

km/s

 

 

knot

knots

 

 

*meter per second

m/s

 

 

micrometer per second

mum/s

 

 

mile per hour

mph

 

 

millimeter per second

mm/s

NU_VOLTAGE

Compendex and Inspec

gigavolts

GV

 

 

kilovolts

kV

 

 

megavolts

MV

 

 

microvolts

muV

 

 

millivolts

mV

 

 

nanovolts

nV

 

 

picovolts

PV

 

 

teravolts

TV

 

 

*volts

V

NU_VOLUME

Compendex

centiliter

cL

 

 

cubic centimeter

cm3

 

 

cubic foot

ft3

 

 

fluid ounce

floz

 

 

gallon

gallon

 

 

cubic inch

in3

 

 

cubic kilometer

km3

 

 

liter

L

 

 

*cubic meter

m3

 

 

microliter

muL

 

 

cubic mile

mi3

 

 

milliliter

mL

 

 

cubic millimeter

mm3

 

 

cubic yard

yd3

NU_VOLUME_CHARGE_DENSITY

Compendex

*coulomb per cubic meter

C/m3

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