Gas Metrology and Classical 

Methods

Franklin R. Guenther

NIST

100 Bureau Drive

Gaithersburg MD 20899-8393
NIST Gas NTRM Meeting

 Agenda:

 1:30 Welcome

 1:45 Summarizing the first 8 years of the gas 

NTRM Program (Bill Dorko)

 2:30 Proposal for new gas NTRM certification 

program

 3:00 Discussion

 3:45 ISO TC158 Discussion

 4:30 Adjourn
1679C 100 ppm CO in N2 13

1680B 500 ppm CO in N2 30

1681B 1000 CO in N2 48

1683B 50 ppm NO in N2 27

1684B 100 ppm NO in N2 55

1685B 250 ppm NO in N2 50

1686B 500 ppm NO in N2 50

1687B 1000 ppm NO in N2 44

1693A 50 ppm SO2 in N2 30

1694A 100 ppm SO2 in N2 59

1696A 3500 ppm SO2 in N2 29

1800 Non-Methane Organic Carbon (NMOC) in N2 9

1804A Ambient Toxic Organics in N2 0

2612A 10 ppm CO in Air 35

2613A 20 ppm CO in Air 32

2614A 45 ppm CO in Air 17

2619A 0.5% CO2 in N2 38

2620A 1.0% CO2 in N2 32

2621A 1.5% CO2 in N2 42

2622A 2.0% CO2 in N2 25

2623A 2.5% CO2 in N2 16

2624A 3.0% CO2 in N2 40

SRM# Description !Total

1625 10 cm SO2 Permeation Device 51

1626 5 cm SO2 Permeation Device 22

1658A 1 ppm Methane in Air 51

1659A 10 ppm Methane in Air 20

1660A 4 ppm Methane, 1 ppm Propane in Air 26

1661A 500 ppm SO2 in N2 20

1662A 1000 ppm SO2 in N2 19

1663A 1500 ppm SO2 in N2 23

1664A 2500 ppm SO2 in N2 25

1665B 3 ppm Propane in Air 22

1666B 10 ppm Propane in Air 2

1667B 50 ppm Propane in Air 4

1668B 100 ppm Propane in Air 4

1669B 500 ppm Propane in Air 1

1671 342 ppm CO2 in Air 21

1672 351 ppm CO2 in Air 21

1674B 7% CO2 in N2 38

1675B 14% CO2 in N2 28

1676A 362 ppm CO2 in Air 0

1677C 10 ppm CO in N2 0

1678C 50 ppm CO in N2 48

NIST Gas SRM Status
2625A 3.5% CO2 in N2 40

2626A 4.0% CO2 in N2 14

2627A 5 ppm NO in N2 0

2628A 10 ppm NO in N2 0

2629A 20 ppm NO in N2 7

2630 1500 ppm NO in N2 17

2631A 3000 ppm NO in N2 34

2635A 25 ppm CO in N2 29

2636A 250 ppm CO in N2 17

2637A 2500 ppm CO in N2 18

2638A 5000 ppm CO in N2 14

2639A 1% CO in N2 34

2640A 2% CO in N2 40

2641A 4% CO in N2 32

2642A 8% CO in N2 13

2643A 100 ppm Propane in N2 0

2644A 250 ppm Propane in N2 0

2645A 500 ppm Propane in N2 0

2646A 1000 ppm Propane in N2 0

2647A 2500 ppm Propane in N2 0

2648A 5000 ppm Propane in N2 0

2649A 1% Propane in N2 0

2650 2% Propane in N2 0

2657A 2% Oxygen in N2 42

2658A 10% Oxygen in N2 39

2659A 21% Oxygen in N2 36

2660 Oxides of Nitrogen in Air 43

2727 1.6% CO, 600 ppm Propane and 11% CO2 in N2 0

2728 8% CO , 3000 ppm Propane and 14% CO2 in N2 0

2730 5 ppm H2S in N2 84

2731 20 ppm H2S in N2 54

2735 800 ppm NO in N2 31

2736 2000 ppm NO in N2 0

2740 10% CO in N2 22

2741 13% CO in N2 1

2745 16% CO2 in N2 29

2750 50 ppm CH4 in Air 18

2751 100 ppm CH4 in Air 11

2764 0.25 ppm Propane in air 29

NIST Gas SRM Status
Gas Standards Survey

Priority List

Low Concentration NO (0.1 - 1 ppm)

Hydrogen Chloride (0.5 - 500 ppm)

Ammonia (1-200 ppm)

Low Concentration SO2 (0.5 to 1 ppm)

Chlorine (1 - 1000 ppm)

Global Warming gases

Mercury
CCQM Intercomparisons

 BTX – ongoing

 Ethanol

 CO,CO2, Propane

 Future

 Global Warming

 Low Conc NO, SO2

 Ozone

 Others?
Group Structure

 Classical Methods

 4 Scientists

 STRS Support –

30%

 SRM support – 60 %

 Gas Metrology

 7 Scientists

 4 Technicians

 STRS Support – 27 %

 OA Support – 6 %

 Standards Activities

 SRM – 20 %

 Customer – 36 %

 Ozone Program 

Added in 1999
International Activities

 Classical Methods

 CCQM

 pH, Conductivity, 

Purity assessment

 SIM

 pH Intercomparison

 Course

 Bilateral

 Conductivity – DFM, 

OMH

 Gas Metrology

 CCQM

 BTX Intercomparison

 SIM

 Auto Exhaust 

Intercomparison

 Course

 Bilateral

 NMi – Inorganic Gas

 NPL – Organic, IR DB
Traceability

 Industry Requirements

 To a National Standard

 Global Economy requires global 

traceability

 European Directive for health monitors – just 

the beginning

 Specialty Gas Industry – 3 to 4 global 

companies
Gas NTRM Program

 SGC Produces NTRM

 SGC Analyzes Batch

 NIST Reviews data, selects cylinders

 NIST analyzes selected cylinders

 NIST certifies batch using NIST/SGC 

data

 SGC retains NTRM batch for use/sale
Program Results

 8 years experience with program

 Steady growth to $500K annually

 Approx 80 batches

 2500 - 3000 cylinders

 125000 – 150000 traceable standards

 EPA Protocol Gas Standards

 Accepted by EPA

 Global Community 

 Acceptance, copied
NTRM - Future

 Effectively replace most gas SRMs

 Promote NTRM sale to end users

 Remove individual batch certification by 

NIST
New Gas NTRM Program

 SGC is certified to produce gas NTRMs

 Must have successful history of NTRM 

production

 Accredited to ISO 17025

 Analytical systems are certified for NTRM 

certification

 Using p-NTRM certified at NIST
New Gas NTRM Program

 SGC sends candidate p-NTRM to NIST

 Concentration suite to cover range

 NIST certifies p-NTRM against PSMs

 Best uncertainty possible

 Better than available SRMs

 Certified for 1 year only
New Gas NTRM Program

 SGC uses p-NTRM to certify NTRM

 Within range of suite, using approved 

analytical system

 Certified value and uncertainty generated 

by NIST software

 Certificate generated by software

 Data sent to NIST quarterly
New Gas NTRM Program

 NIST Quality Assurance

 Through p-NTRM and Software

 May call for NTRM periodically

 Will send challenge cylinder to SGC

 SGC certifies and send certificate to NIST

 Certification must agree with NIST analysis

 Within stated uncertainty
New Gas NTRM Program

 Elimination of most gas SRMs

 Some always necessary

 NTRM Production not limited

 p-NTRM available to SIM countries

 International Acceptance

 NIST able to turn to new gas standards
ISO TC 158: Analysis of Gases

 No active US Participation

 Participating Members (Voting):

Belgium Portugal

Czech Republic Russian Federation

Germany Spain

Hungary Sweden

Italy Ukraine

Netherlands (S) United Kingdom

Poland
Working Groups

1. Terminology

2. Quality assurance of gas analysis

3. Gravimetric methods

4. Comparison methods and certificates

5. Static and dynamic volumetric 

methods

6. Quantities of composition
Standards

 FDIS 6141: Requirements on certificates for gases and gas 

mixtures

 DIS 6142: Preparation of calibration gas mixtures – Gravimetric 

method

 DIS 6143.2: Determination of the composition of calibration gas 

mixtures – comparison methods

 DIS 6144.2: Preparation of calibration gas mixtures – static 

volumetric methods

 CD 6145-1: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – methods of calibration
Standards

 CD 6145-2: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – Volumetric pumps

 6145-3: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – periodic injections into a flowing gas 

stream

 6145-4: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – continuous injection method

 6145-5.2: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – Capillary calibration devices

 6145-6: Preparation of calibration gas mixtures – Dynamic 

volumetric methods – Critical orifices
Standards

 6145-7: Preparation of calibration gas mixtures –

Dynamic volumetric methods – Thermal mass flow 

controllers

 6145-8: Preparation of calibration gas mixtures –

Dynamic volumetric methods – Diffusion

 6145-9: Preparation of calibration gas mixtures –

Dynamic volumetric methods – Saturation methods

 6145-10: Preparation of calibration gas mixtures –

Dynamic volumetric methods – Permeation methods

 7504: Vocabulary
Standards

 14166: Pure gases – Requirements for presentation 

of the results of gas purity analysis

 14167: General quality assurance aspects in the use 

and preparation of reference gas mixtures – guidlines

 14912: Quantities of composition

 15796: Detection and correction of analytical bias

 16664: Handling of calibration gases and gas 

mixtures - guidelines
U.S. Participation

 ANSI

 Requires formation of Technical Activity 

Group (TAG)

 Freely open to all who wish to participate

 Reports to ANSI

 Requires yearly financial support to ANSI

 $3155 for TAG

 $490 per Working Group

 Must be accredited by ANSI
Possible TAG Secretariat

 ASTM through D22

 Will they take on another ISO TG?

 NIST 

 Is this a NIST Role??

 Requires support from?

 Others?