A division of California Tool & Welding Supply.


Å Angstrom(s)

AA Atomic Absorption

abs absolute

ACGIH American Conference of Governmental Industrial Hygienists

ASTM American Society for Testing Materials

atm atmosphere(s)

avg average



Bar Bureau of Automotive Repair

bar Unit of pressure equal to 100,000 pascals

bp boiling point

Btu British thermal unit(s)



CAA Clean Air Act

cal calorie(s)

CAS Chemical Abstract Services

ccm cubic centimeter(s) per minute

ccs cubic centimeter(s) per second

CEM Continuous Emission Monitor

cf cubic feet

CFCs Chlorofluorocarbons

CFR Code of Federal Regulations

CGA Compressed Gas Association

cm centimeter(s)

cm2 square centimeter

cm3, cc cubic centimeter

COA Certificate of Analysis

COC Certificate of Conformance

CP Chemically Pure

Cp specific heat at constant pressure

Cv specific heat at constant volume

Cv coefficient of flow

°C degree(s) Celsius



DID Discharge Ionization Detector

DISS Diameter Index Safety System

DOT Department of Transportation



ea each

ECD Electron Capture Detector

EPA Environmental Protection Agency



FID Flame Ionization Detector

FNPT Female National Pipe Thread

F.O.B. Freight on Board

FPD Flame Photometric Detector

FPT Female Pipe Thread

ft foot, feet

ft3 cu ft cubic foot (feet)

FTIR Fourier Transform Infrared Spectrometer or Spectroscopy

°F degree(s) Fahrenheit



g gram(s)

gal gallon(s)

GC Gas Chromatography or Chromatograph

GMIS Gas Manufacturers Intermediate Standard

GMP Good Manufacturing Practice(s)

GPA Gas Processors Association



Hall Electrolytic Conductivity Detector

HAP Hazardous Air Pollutants

HID Helium Ionization Detector

hr hour

Hz hertz



ICP Inductively Coupled Plasma (Spectroscopy)

ID identification or inside diameter

IDLH Immediately Dangerous to Life or Health

in inch

in3 cu in cubic inch(es)

ISO International Organization for Standardization



J joule



K Kelvin

kg kilogram(s)

kPa Kilopascal(s)

°K degree(s) Kelvin



L liter(s)

lb pound(s)

LC Liquid Chromatography

LEL Lower Explosive Limit

Lpm liters per minute



μ micron(s), 10–6 m

m3 cubic meter(s)

mA milliampere

max maximum

mg milligram(s)

min minute(s)

ml milliliter(s)

mm millimeter(s)

MNPT Male National Pipe Thread

mol.wt. molecular weight

MOS Metal Oxide Semiconductor

MPT Male Pipe Thread

mp melting point

MS Mass Spectrometry

MTBE Methyl Tertiary Butyl Ether


MVFS Male Vacuum Face Seal

MW molecular weight



N/A Not Applicable

nbp normal boiling point

NDIR Non–Dispersive Infrared Analyzer

NDUV Non–Dispersive Ultraviolet Analyzer

NER normal evaporation rate

NF National Formulary

NFPA National Fire Protection Association

NIOSH National Institute for Occupational Safety and Health

NIST National Institute of Standards and Technology

nm nanometer(s)

NMR Nuclear Magnetic Resonance Spectroscopy

No number

nom nominal

NOS Not Otherwise Specified

NPD Nitrogen/Phosphorous Detector

NPT National Pipe Thread

NTP Normal Temperature and Pressure

NTRM NIST Traceable Reference Material



OD Outside Diameter

Ohm–cm ohms centimeter

OSHA Occupational Safety and Health Administration

oz ounce(s)



Pa Pascal(s)

PAMS Photochemical Air Monitoring Systems

PID Photo Ionization Detector

ppb part(s) per billion

ppba part(s) per billion atomic

ppbv part(s) per billion by volume

ppbw part(s) per billion by weight

ppm part(s) per million

ppma part(s) per million atomic

ppmv part(s) per million by volume

ppmw part(s) per million by weight

ppt part(s) per trillion

ppta part(s) per trillion atomic

pptv part(s) per trillion by volume

pptw part(s) per trillion by weight

psi pound(s) – force per square inch

psia pound(s) – force per square inch absolute

psig pound(s) – force per square inch gauge



QA Quality Assurance

QC Quality Control



Ra Roughness average

RFO Restricted Flow Orifice

°R degree(s) Rankine



scc standard cubic centimeters

sccm standard cubic centimeters per minute

sccs standard cubic centimeters per second

scfh standard cubic feet per hour

scfm standard cubic feet per minute

scfs standard cubic feet per second

SDS Safety Data Sheet

sec second(s)

SFC Supercritical Fluid Chromatography

SFE Supercritical Fluid Extraction

slpm standard liters per minute

  1. gr. specific gravity
  2. vol. specific volume

SRM Standard Reference Materials

SS Stainless Steel

STEL Short Term Exposure Limit

STP Standard Temperature and Pressure



TCD Thermal Conductivity Detector

TEA Transversely Excited Atmosphere

THC Total Hydrocarbon Content

TLV Threshold Limit Value

tp triple point

TPH Total Petroleum Hydrocarbons

TWA Time Weighted Average



UEL Upper Explosive Limiit

UHP Ultra High Purity

USP United States Pharmacopoeia



VAC Volts Alternating Current

VDC Volts Direct Current

VOC Volatile Organic Compounds

vol volume

vol% volume percent



w.c. water column pressure

wt. weight 

wt% weight percent

wt ppm weight parts per million



yd yard(s)


> Greater than

Greater than or equal

< Less than

Less than or equal