ISO 17034 and ISO 17025 table of ranges and uncertainties for hydrogen-enriched fuel gases

This table was reviewed on 19 March 2025 and refers to the ISO 17034 scope (Issue No. 006) and ISO 17025 scope (Issue No. 059) for EffecTech. For details of the Expanded Measurement Uncertainty (k = 2) for each component, please check the most recent version of the ISO 17025 scope.

Certified Reference Materials (CRM)

Component	Range (amount fraction % mol/mol)
nitrogen	0.1 to 22
carbon dioxide	0.05 to 15
methane	34 to 100
ethane	0.1 to 35
propane	0.05 to 15
iso-butane	0.01 to 2
n-butane	0.01 to 2
neo-pentane	0.002 to 0.35
iso-pentane	0.005 to 0.35
n-pentane	0.005 to 0.35
n-hexane	0.005 to 0.35
2-methylpentane	0.001 to 0.35
3-methylpentane	0.001 to 0.35
2,2-dimethylbutane	0.001 to 0.35
benzene	0.001 to 0.2
cyclohexane	0.001 to 0.2
n-heptane	0.001 to 0.2
toluene	0.001 to 0.1
methylcyclohexane	0.001 to 0.1
n-octane	0.0005 to 0.05
n-nonane	0.0001 to 0.02
n-decane	0.0001 to 0.005
helium	0.005 to 0.2
hydrogen	0.005 to 20
oxygen	0.05 to 22.5*

*The upper limit for oxygen may be limited due to restrictions in place required for the safe manufacture of such mixtures.

Primary Reference Gas Mixtures (PRGM)

Component	Range (amount fraction % mol/mol)
nitrogen	0.02 to 25
carbon dioxide	0.05 to 25
methane	34 to 100
ethane	0.1 to 35
propane	0.05 to 20
iso-butane	0.01 to 2
n-butane	0.01 to 2
neo-pentane	0.001 to 0.5
iso-pentane	0.002 to 0.6
n-pentane	0.002 to 0.6
n-hexane	0.001 to 0.5
2-methylpentane	0.001 to 0.35
3-methylpentane	0.001 to 0.35
2,2-dimethylbutane	0.001 to 0.35
benzene	0.001 to 0.2
cyclohexane	0.001 to 0.2
n-heptane	0.001 to 0.2
toluene	0.001 to 0.1
methylcyclohexane	0.001 to 0.1
n-octane	0.0005 to 0.05
n-nonane	0.0001 to 0.02
n-decane	0.0001 to 0.005
helium	0.005 to 0.2
hydrogen	0.005 to 0.2

Not sure what the difference is between PRGMs and CRMs?

Find out more about our calibration gases here.

Component	range	calibration and measurement capability (CMC)*
	amount fraction (% mol/mol)	amount fraction (% mol/mol)
hydrogen	0.1 to 20	0.25 % relative + 0.0020
nitrogen	0.1 to 12	0.25 % relative + 0.0005
carbon dioxide	0.1 to 8	0.2 % relative + 0.0002
methane	35 to 100	0.11 – 0.10 % relative
ethane	0.1 to 20	0.25 % relative + 0.0005
propane	0.1 to 8	0.3 % relative + 0.0001
iso-butane	0.02 to 0.15 0.15 to 1.2	0.00045 0.3 % relative
n-butane	0.02 to 0.15 0.15 to 1.2	0.00045 0.3 % relative
neo-pentane	0.01 to 0.35	0.7 % relative + 0.0001
iso-pentane	0.01 to 0.35	0.5 % relative + 0.0001
n-pentane	0.01 to 0.35	0.5 % relative + 0.0001
n-hexane	0.001 to 0.35	1.0 % relative + 0.0001
2-methylpentane	0.001 to 0.35	1.3 % relative + 0.00005
3-methylpentane	0.001 to 0.35	1.3 % relative + 0.00005
2,2-dimethylbutane	0.001 to 0.35	1.3 % relative + 0.00005
benzene	0.001 to 0.2	1.3 % relative + 0.00005
cyclohexane	0.001 to 0.2	1.3 % relative + 0.00005
n-heptane	0.001 to 0.2	1.3 % relative + 0.00005
toluene	0.001 to 0.1	1.3 % relative + 0.00005
methylcyclohexane	0.001 to 0.1	1.3 % relative + 0.00005
n-octane	0.0005 to 0.05	1.3 % relative + 0.00005
n-nonane	0.0005 to 0.02	1.3 % relative + 0.00005
n-decane	0.0005 to 0.005	1.3 % relative + 0.00005
	amount fraction (µmol/mol or % mol/mol)	amount fraction (% µmol/mol)
oxygen	10 to 100 100 to 1000 0.1 % to 1.0 % 1.0 % to 22.5 %**	1.6 % relative + 0.1 0.9 % relative + 0.5 0.7 % relative + 1.0 0.18 % relative + 30