NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

December 20, 2023

1 

Executive Summaries from the NIST OWM Analysis of the

2024 NCWM Specifications and Tolerances (S&T) 

Interim Meeting Agenda 

The NIST OWM Executive Summary is extracted from the NIST OWM Analysis. This provides the 

NIST OWM community with high level points that summarize the technical aspects and 

recommendations for the Item Under Consideration. The full NIST OWM Analysis can be viewed at 

https://www.nist.gov/pml/owm/publications/owm-technical-analysis. NIST OWM offers these 

comments and recommendations based upon information and input available as of the date of this report. 

Language shown in bold face print by striking out information to be deleted and underlining

information to be added. Requirements that are proposed to be nonretroactive are printed in bold faced 

italics. 

For additional information or assistance please contact a NIST OWM Technical Advisor: 

Jan Konijnenburg, S&T Committee, jan.konijnenburg@nist.gov or (301) 975-4004 

Diane Lee, S&T Committee, diane.lee@nist.gov or (301) 975-4405 

Loren Minnich, S&T Committee, loren.minnich@nist.gov (202) 430-0435 

Juana Williams, S&T Committee, juana.williams@nist.gov or (301) 975-3989

NIST OWM Executive Summary

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Subject Series List for the Specifications and Tolerances Committee

Handbook 44 – General Code......................................................................................................GEN Series

Scales......................................................................................................................................SCL Series

Belt-Conveyor Scale Systems................................................................................................BCS Series

Automatic Bulk Weighing Systems.....................................................................................ABW Series

Weights..................................................................................................................................WTS Series

Automatic Weighing Systems.............................................................................................. AWS Series

Weigh-In-Motion Systems used for Vehicle Enforcement Screening ..................................WIM Series

Liquid-Measuring Devices................................................................................................... LMD Series

Vehicle-Tank Meters............................................................................................................ VTM Series

Liquefied Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices..................LPG Series

Hydrocarbon Gas Vapor-Measuring Devices........................................................................HGV Series

Cryogenic Liquid-Measuring Devices ..................................................................................CLM Series

Milk Meters.......................................................................................................................... MLK Series

Water Meters........................................................................................................................ WTR Series

Mass Flow Meters................................................................................................................MFM Series

Carbon Dioxide Liquid-Measuring Devices.......................................................................... CDL Series

Hydrogen Gas-Metering Devices.........................................................................................HGM Series

Electric Vehicle Refueling Systems.......................................................................................EVF Series

Vehicle Tanks Used as Measures..........................................................................................VTU Series

Liquid Measures................................................................................................................... LQM Series

Farm Milk Tanks...................................................................................................................FMT Series

Measure-Containers.............................................................................................................. MRC Series

Graduates...............................................................................................................................GDT Series

Dry Measures ........................................................................................................................DRY Series

Berry Baskets and Boxes....................................................................................................... BBB Series

Fabric-Measuring Devices..................................................................................................... FAB Series

Wire-and Cordage-Measuring Devices................................................................................WAC Series

Linear Measures......................................................................................................................LIN Series

Odometers .............................................................................................................................ODO Series

Taximeters...............................................................................................................................TXI Series

Timing Devices ......................................................................................................................TIM Series

Grain Moisture Meters (a)....................................................................................................GMA Series

Grain Moisture Meters (b)....................................................................................................GMB Series

Near-Infrared Grain Analyzers............................................................................................... NIR Series

Multiple Dimension Measuring Devices............................................................................. MDM Series

Electronic Livestock, Meat, and Poultry Evaluation Systems and/or Devices.......................LVS Series

Transportation Network Measuring Systems.........................................................................TNS Series

Other Items...................................................................................................................................OTH Series
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Table of Contents

SCL – Scales ............................................................................................................................ 4

AWS – Automatic Weighing Systems Code........................................................................... 7

WIM – Weigh-in-Motion Systems – Tentative Code............................................................... 9

LMD – Liquid Measuring Devices ......................................................................................... 10

VTM – Vehicle Tank Meters ................................................................................................... 11

LPG – Liquified Petroleum Gas and Anhydrous Ammonia Liquid-Measuring Devices .... 11

MLK – MILK METERS............................................................................................................. 14

HGM – Hydrogen Gas-Measuring Devices ........................................................................... 15
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EVF – Electric Vehicle Fueling Systems............................................................................... 15

GMA – Grain Moisture Meters 5.56 (a).................................................................................. 24

OTH – Other Items ................................................................................................................. 25

Item Block 1 (B1) Transfer Standard.................................................................................. 27
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SCL – Scales

NIST OWM Executive Summary for SCL-24.1 – S.1.7. Capacity Indication, Weight Ranges, and 

Unit Weights

NIST OWM Recommendation: Withdrawn

• It is unclear what problem the submitter is trying to solve. It appears that the submitter 

misinterpreted the term “computing scale”. A computing scale is defined as: “One that 

indicates the money values of amounts of commodity weighed, at predetermined unit prices, 

throughout all or part of the weighing range of the scale.”

• The term “electronic” was included to differentiate between analog computing scales, e.g., 

drum or fan type scales, from scales that display weight values in an electronic digital format.

• OWM believes the proposed change is ambiguous and would cause more confusion than the 

terms used in the current language.

NIST OWM Executive Summary for SCL-24.2. − Multiple Sections Regarding Tare

NIST OWM Recommendation: Developing/Assigned

• NIST OWM recognizes the issues raised by the submitter and is of the opinion that the 

proposed amendments help solve these issues. However, as the submitter already indicated, 

the item is not yet fully developed. NIST OWM supports further development of the item, 

either by the submitter or by a task group.

NIST OWM Executive Summary for SCL-22.3 – Single-Draft Vehicle Weighing and UR.3.4. Axle 

and Axle Group Weight Values.

NIST OWM Recommendation: Voting, with the recommended edits as indicated below.

• The adoption of GEN-22.1 in 2022, which amended paragraph G-A.1. Commercial and LawEnforcement Equipment of NIST Handbook 44 clarifying that weighing and measuring 

equipment used for the purpose of providing a weight or measure for a fee constitutes 

commercial use of that equipment, necessitated this proposal.

• The WWMA & NEWMA regions had concerns with “split-weighing”:

o SCL-22.1 was adopted at the 2023 NCWM Annual Meeting and adds paragraph S.1.15. to 

NIST Handbook 44 requiring the recorded value be identified as “Not-Legal-For-Trade” 

when not all weights value were determined simultaneously (split-weighed).

o Paragraph UR.3.3. will still require a vehicle or vehicle combination to be weighed 

“commercially” as a single draft except as noted in subparts (a) and (b) of the paragraph.

o The “Note” in UR.3.3. currently exempts highway-law-enforcement scales and scales used 

for the collection of statistical data from having to weigh in single drafts. This item would 
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NIST OWM Executive Summary for SCL-22.3 – Single-Draft Vehicle Weighing and UR.3.4. Axle 

and Axle Group Weight Values.

add another exemption to this paragraph for scales used to weigh axle loads, axle-group 

loads, and the gross weight of vehicles and coupled-vehicle combinations for a fee, when 

those values are only used “to determine compliance with highway legal load limits and 

safe distribution of the load”.

o SCL-22.3 also adds a new paragraph, UR.3.4. which clarifies that it is acceptable to use 

multi-platform vehicle scale systems to charge a fee for the commercial service of 

providing customers (usually truckers) axle weights, axle group weights, and the gross 

weight of their vehicles to enable them to determine compliance with state and federal legal 

load limits.

o In addition, this new UR.3.4. paragraph clarifies how these weights must be obtained to 

be used as commercial values, i.e., the summed total of a vehicle that is “splitweighed” cannot be used as the basis for a commercial transaction.

• OWM proposed amendments to this item in May 2023 based on feedback received from the 

SMA during and after the 2023 NCWM Interim Meeting and requested that the Committee 

replace the current proposal in SCL-22.3. The item under consideration reflects these 

amendments.

• OWM suggests the following minor edits: 

o Remove the word “axle-“ throughout the item and replace it with “axle load” instead of 

“axle-“ not including the term “axle-group loads”. 

o Add the word “established” between the words “with” and “highway” in the last paragraph 

of UR.3.3., formerly the “Note”.

o Remove the “s” from “subparts” in the last paragraph of UR.3.4.

o Add the amended date to paragraph UR.3.3. and the added date to UR.3.4. 

o The item would then appear as this: 

UR.3.3. Single-Draft Vehicle Weighing. – A vehicle or a coupled-vehicle combination shall be 

commercially weighed on a vehicle scale only as a single draft. That is, the total weight of such a 

vehicle or combination shall not be determined by adding together the results obtained by 

separately and not simultaneously weighing each end of such vehicle or individual elements of 

such coupled combination. However, the weight of: 

(a) a coupled combination may be determined by uncoupling the various elements (tractor, 

semitrailer, trailer), weighing each unit separately as a single draft, and adding together the 

results; or
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NIST OWM Executive Summary for SCL-22.3 – Single-Draft Vehicle Weighing and UR.3.4. Axle 

and Axle Group Weight Values.

(b) a vehicle or coupled-vehicle combination may be determined by adding together the 

weights obtained while all individual elements are resting simultaneously on more than 

one scale platform.

Note: This paragraph does not apply to highway-law-enforcement scales, and scales used for 

the collection of statistical data, or scales used to charge a fee for the service of providing 

weights of the different axle loads, axle-group loads, and total weight of vehicles and 

coupled-vehicle combinations when the only use of those values is to determine 

compliance with established highway legal load limits and safe distribution of the load. 

(Added 1992) (Amended 20XX)

And

UR.3.4. Weighing of Axle Loads and Axle-Group Loads – Establishing weight values for the 

different individual axle loads and axle-group loads of a vehicle or coupled-vehicle combination 

is oftentimes necessary to verify compliance with established highway weight requirements and 

safe distribution of the load. When a fee is charged for this service, the scale’s application is 

considered “commercial” under the provisions of paragraph G-A.1. Commercial and Law 

Enforcement Equipment and the scale shall comply with all applicable NIST Handbook 44 

requirements for commercial weighing systems. 

When weight values for axle loads and/or axle-group loads are obtained using multipleindependent platform vehicle scale systems in which all parts of the vehicle or coupled-vehicle 

combination being weighed are simultaneously positioned on live elements of the scale, the 

values for the different axle loads and axle-group loads may be summed to establish the legal 

gross vehicle weight. 

In no case, however, shall a summed result of the different axle loads and axle-group loads of 

a vehicle or coupled vehicle combination weighed in multiple drafts be used as the legal gross 

weight unless subpart (a) or (b) of paragraph UR.3.3. Single-Draft Vehicle Weighing is met.

(Added 20XX)

• With these minor edits OWM requests a Voting status

• OWM notes this item is currently in a “Developing” status. OWM encourages a review of the 

most current proposal and continues to seek feedback from all interested parties or individuals. 

NIST OWM Executive Summary for SCL-23.3 – Verification Scale Division e: Multiple Sections 

Including, T.N.1.3., Table 6., T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table 

S.6.3.a., Table S.3.6.b., Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8. 

NIST OWM Recommendation: Voting

• NIST OWM is of the opinion that the proposal is fully developed and supports a Voting status 

for this group of items. NIST OWM would like to stress the importance of this item. The 

current scale code in Handbook 44 contains several contradictions and inconsistencies with 
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NIST OWM Executive Summary for SCL-23.3 – Verification Scale Division e: Multiple Sections 

Including, T.N.1.3., Table 6., T.N.3., T.N.4., T.N.6., T.N.8., T.N.9., T.1., T.2., S.1.1.1., T.N.1.2., Table 

S.6.3.a., Table S.3.6.b., Appendix D, S.1.2.2., Table 3., S.5.4., UR.3., Table 8. 

respect to the use of the terms “scale division”, and “verification scale division”. This leads to 

confusion and non-uniformity in the application of the code.

• The proposal presented by the task group is meant to clean up the code and bring clarification of 

the requirements with respect to e and d.

NIST OWM Executive Summary for SCL-24.3 – Table 6. Maintenance Tolerances

NIST OWM Recommendation: Informational

• OWM supports the effort to provide additional clarity to Table 6, specifically the interpretation 

of Class III L tolerances.

• Our office supports an Informational status until the weights & measures community agrees 

which of the proposed versions of Table 6 accomplishes that goal. 

NIST OWM Executive Summary for SCL-22.2 – UR.1. Selection Requirements, UR.1.X. Cannabis

1

NIST OWM Recommendation: Assigned

• The proposed amendments to Table 7a are ambiguous. The weighing of all cannabis products 

is assigned to accuracy classes I, II and III. This will lead to confusion in the field. For this 

reason, OWM recommends this item remains assigned to the Task Group. OWM offers to 

assist the Cannabis Task Group in developing a more appropriate proposal for the amendment 

of Table 7a.

____________________

1 In contrast to hemp, marijuana remains a Schedule I substance under the Controlled Substances Act. NIST does 

not have a policy role related to the legalization of the production, sale, distribution, or use of cannabis (including 

hemp and marijuana). NIST participates in the National Conference of Weights and Measures (NCWM) as part 

of NIST’s statutory mission to promote uniformity in state laws, regulations, and testing procedures.

AWS – Automatic Weighing Systems Code

NIST OWM Executive Summary for AWS-24.1 – N.1.5. Test Loads

NIST OWM Recommendation: Voting, with recommended changes.

• OWM agrees with the submitter that the language in paragraph N.1.5. can be interpreted in 

different ways.
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NIST OWM Executive Summary for AWS-24.1 – N.1.5. Test Loads

• Paragraph N.1.5. and Table N.1.5. Test Loads apply to all Automatic Weighing Systems which 

includes: 

o Automatic weigh-labelers;

o Combination automatic and non-automatic weigh-labelers;

o Automatic checkweighers; 

o Combination automatic and non-automatic checkweighers; and

o Automatic gravimetric filling machines that weigh discrete loads or single loads of loose 

materials and determine package and production lot compliance with net content 

representations. 

• The subsequent paragraphs, N.2. & N.3. apply to Weigh-Labelers and Automatic 

Checkweighers, respectively.

• N.2. specifies how test loads are applied to Weigh-Labelers

• N.3. specifies how test loads are applied to Checkweighers.

• Because the application of test loads is specified in N.2. & N.3., OWM suggests amending 

N.1.5. as follows:

N.1.5. Tests Loads. – A performance test shall consist of four separate test runsbe conducted 

atwith a minimum of four different test loads according to Table N.1.5. Test Loads.

• This would clarify what test loads are required and would retain the current requirements 

pertaining to the application of test loads.

NIST OWM Executive Summary for AWS-24.2 – N.1.6. Influence Factor Testing 

NIST OWM Recommendation: Voting

• The effect of influence factors is evaluated under controlled conditions, typically only during 

NTEP evaluation.

• As identified by the submitter, NCWM Publication 14 has procedures for evaluating influence 

factors when testing AWS either statically or dynamically, depending on the system’s 

capabilities.

• A search of NIST Handbook 44 shows that only one other section, 5.58. Multiple Dimension 

Measuring Devices, has a note that mentions influence factors. Typically, NIST HB 44 
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NIST OWM Executive Summary for AWS-24.2 – N.1.6. Influence Factor Testing 

specifies tolerances associated with influence factors but does not specify a test (N. paragraph 

or test note).

• OWM agrees that this note is not needed and supports its removal.

NIST OWM Executive Summary for AWS-24.3 – N.22.3. Shift Test (Dynamic)

NIST OWM Recommendation: Voting

• NIST HB 44 currently has no shift test specified for devices that operate in the automatic mode 

only. Devices operating statically are tested for eccentricity with a test load equal to 1⁄2 

capacity. OIML R-51 specifies conducting this test at 1/3 capacity.

• Adoption of this item would align NIST Handbook 44 with OIML R-51, not only with the type 

of test but the test load required (1/3 capacity)

• Adding this will facilitate field testing of these devices to ensure accuracy when off center 

loading occurs.

WIM – Weigh-in-Motion Systems – Tentative Code

NIST OWM Executive Summary for WIM-23.1 – Remove Tentative Status and Amend Numerous 

Sections Throughout

NIST OWM Recommendation: Informational 

• NIST OWM applauds the efforts of the submitter to address the concerns raised and 

incorporate the feedback received from the community into the item under consideration. Our 

office supports this most recent version of the item and is of the opinion that most major

concerns have been sufficiently addressed by the submitters.

• We agree that separating Section 2.25. which applies to WIM Systems used to screen and is a 

tentative code from this new proposed section, 2.26. which will apply to WIM Systems used to 

enforce highway load limits, is the best approach. 

• The only concern we still have is the with paragraph N.1.3. Reference Scale, which allows the 

use of a single platform vehicle scale to weigh the axles or axle-groups of a reference vehicle 

which are then summed to determine the gross vehicle weight. Using a single platform vehicle 

scale to weigh axles or axle-groups in isolation, as N.1.3.2 requires, is impractical. It would 

seem this is only possible using an axle-load scale.

• Even if N.1.3. didn’t require the axles or axle-groups of a reference vehicle to be weighed in 

isolation, unless the approach for the scale is of sufficient length to ensure the reference vehicle 
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NIST OWM Executive Summary for WIM-23.1 – Remove Tentative Status and Amend Numerous 

Sections Throughout

is in the same plane as the vehicle scale while the reference values are being determined, there 

is concern that the values determined would be inaccurate. 

• Because this version of the item wasn’t available for review by the regions in its entirety and 

due to the number of significant changes being proposed our office supports an Informational 

status to allow for further consideration. 

LMD – Liquid Measuring Devices

NIST OWM Executive Summary for LMD-24.1 – N.4. Normal Tests

NIST OWM Recommendation: Voting with recommended changes.

• For the 2024 edition of NIST Handbook 44, OWM made editorial changes to this paragraph 

based on a request from the submitter of this item. This is the how the paragraph now appears 

in the handbook: 

N.4.1. Normal Tests. – The “normal” test of a device shall be made at the maximum 

discharge flow rate developed under the conditions of installation. Any additional tests 

conducted at flow rates down to and including one-half of the sum of the maximum discharge 

flow rate (MDRF) and the rated minimum discharge flow rate (RMDFR) shall be considered 

normal tests. As a formula, this is stated as:

MMMMMMMM+

2 = mmmmmmmmmmmmmm dd ddddhaaaaaaaa ffffffff ff for additional tests

(Amended 1991 and 2023) 

• For added clarification we suggest adding the word “normal” between the words “additional” 

and “tests” in the formula so it would appear as follows:

MMMMMMMM+

2 = mmmmmmmmmmmmmm dd ddddhaaaaaaaa ffffffff ff for additional normal tests

• To be consistent with other examples currently in NIST Handbook 44, OWM suggests the 

following format for the example proposed by the submitter:

Example: If, under the conditions of installation, a device has a maximum discharge flow 

rate (MDFR) of 9 gpm and a rated minimum discharge flow rate (RMDFR) of 0.5 gpm, 

using the above formula the minimum discharge flow rate for additional normal tests is 

calculated as follows:

99 gggggg + 00. 55 gggggg

22 = 44. 77 gggggg

For this device any test conducted at a flow rate of 9 gpm down to and including 4.75 gpm 

is considered a normal test and the acceptance or maintenance tolerances referenced in 
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Table T.2. Accuracy Classes and Tolerances for Liquid Measuring Devices covered in 

NIST Handbook 44, Section 3.30. are applicable. 

Tests conducted below the minimum discharge flow rate for additional normal tests are 

considered “special” tests and shall be conducted as described in N.4.2. Special Tests. 

The special test tolerances referenced in Table T.2. Accuracy Classes and Tolerances for 

Liquid Measuring Devices covered in NIST Handbook 44, Section 3.30. are applicable. 

• If the S&T Committee accepts the format for the example suggested by OWM, our office will 

support this item for adoption. 

• OWM notes that in the Item Under Consideration the proposed new language is in in bold type 

and should be edited as such so it is clear to the reader that this is new language.

VTM – Vehicle Tank Meters

NIST OWM Executive Summary for VTM-20.2 – Table T.2. Tolerances for Vehicle Mounted Milk 

Meters

NIST OWM Recommendation: OWM supports the Assigned status for this item and encourages the 

Task Group to continue its review of the proposed OIML tolerances for Vehicle Tank Milk Meters. 

• One of the concerns raised is that the proposal includes tolerances for the system and a separate 

tolerance for the meter. 

• NIST OWM observed that a separate tolerance for the meter would apply during OIML type 

evaluation. However, NIST HB 44 only includes requirements for the entire measurement 

system and not separate main elements nor does it have separate tolerances for main elements 

known to be metrologically significant. 

• Aaron Yanker (Colorado) is listed on the NCWM website as the Milk Meter Task Group Chair 

NIST OWM will look forward to more discussion of this item during task group meetings. 

LPG – Liquified Petroleum Gas and Anhydrous Ammonia Liquid-Measuring 

Devices

NIST OWM Executive Summary for LPG-23.1 – S.2.5. Zero-Set-Back Interlock

NIST OWM Recommendation: Withdrawn 

• Zero set-back interlock ensures that a device is returned to zero before another customer or 

services person uses the device for another transaction thus preventing the facilitation of fraud 

per G-S.2. Facilitation of Fraud. 

• The LPG Code paragraphs S.2.5.1 and S.2.5.2 address electronic stationary and other 

stationary devices because the process for zero-set-back interlock operates differently for an 
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NIST OWM Executive Summary for LPG-23.1 – S.2.5. Zero-Set-Back Interlock

electronic stationary device than it does for a stationary retail motor fuel device as described in 

S.2.5.2. but both devices are required to return to zero before another transaction is made.

• The submitter states that only a few transactions for LPG dispenser are for fueling vehicles and 

they are limited to use by trained staff. Paragraphs S.2.5.1 and S.2.5.2 are not dependent on 

who is dispensing the product or how often the device is used as a retail motor dispenser; the 

paragraphs are intended to ensure that the device is so designed that each new transaction starts 

at zero. What happens if they are used more frequently for use in fueling vehicles? 

• According to the requirements both electronic stationary and stationary retail motor fuel 

dispensers must have a zero-setback interlock.

• If this proposal is adopted “Devices Used Exclusively as” would be added to both S.2.5.1. and 

S.2.5.2. to exempt stationary retail motor-fuel devices that are used for purposes other than 

dispensing retail motor-fuel from having a zero-set-back interlock and a note would be added 

to S.2.5.1. that would exempt Analog devices used for purposes other than dispensing retail 

motor-fuel from having a zero-set-back interlock. 

• Is this equitable to other products dispensed, such as gasoline or diesel. The devices that 

dispense these products are required to have a zero-setback interlock and are sometimes used 

to fill containers used for filling gasoline or diesel-powered equipment. Granted, the majority 

of these dispensers are used to fill vehicles; but does this create an unfair market situation 

where some fueling dispensers are required to have zero set-back interlock and others are not? 

• The submitter also stated that proposed changes were introduced for consideration in 2023 to 

allow public refueling of LP Gas with safety precautions and with these new requirements 

zero-setback interlock is needed. How will LPG devices with and without zero-setback 

interlock be fairly- regulated? Is this equitable to other products dispensed, such as gasoline 

dispensers. Gasoline dispensers are required to have a zero-setback interlock, and some are 

used to fill containers used for gasoline- powered equipment. Granted, the majority of gasoline 

dispensers are used to fill vehicles; but does this create an unfair market situation where some 

fueling dispensers are required to have zero set-back interlock and others are not? 

• The submitter also stated that proposed changes were introduced for consideration in 2023 to 

allow public refueling of LP Gas with safety precautions and with these new requirements 

zero-setback interlock is needed. How will LPG devices with and without zero-setback 

interlock be fairly regulated? 
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NIST OWM Executive Summary for LPG-24.1 – S.1.5.7. Retail Motor Fuel Dispenser Liquefied 

Petroleum Gas Retail Motor Fuel Device., S.2.6.1. Electronic Stationary (Other than Stationary 

Retail Motor Fuel Dispensers Liquefied Petroleum Gas Retail Motor Fuel Device). S.6.2. 

Automatic Timeout Pay-at-Pump Retail Motor Fuels Devices Liquefied Petroleum Gas Retail 

Motor Fuel Device, and S.4.3. Location of Marking Information: Retail Motor Fuel Dispensers

Liquefied Petroleum Gas Retail Motor Fuel Device.

NIST OWM Recommendation: Withdraw

• The definition of “liquefied petroleum gas retail motor-fuel device” was added in 2022 for 

inclusion in the 2023 edition of NIST Handbook 44. Currently the definition recognizes the 

terms “retail motor-fuel dispenser” and “retail motor-fuel device” to be the same as and 

interchangeable with “liquefied petroleum gas retail motor-fuel device”.

• OTH-24.1. proposes amending this definition to apply only to those devices with a K15 nozzle. 

OWM does not support this change. 

• If OTH-24.1 is withdrawn, OWM could support these proposed changes as it would replace 

various terms with one term that is defined and applies to this section of the handbook. 

• This item should be blocked with LPG-24.2 and OTH-24.1 if they remain on the agenda.

NIST OWM Executive Summary for LPG-24.2 – S.2.5. Zero-Set-Back Interlock. S.2.5. Zero-SetBack Interlock

NIST OWM Recommendation: Withdrawn/Developing

• If the item remains as proposed it should be withdrawn or be assigned a developing status. 

• OTH-24.1. proposes amending the definition of “liquefied petroleum gas retail motor-fuel 

device” to apply only to those devices with a K15 nozzle. OWM does not support this change 

until the K15 connector is the standard for all LPG powered vehicles. 

• This item should be blocked with LPG-24.1 & OTH-24.1 if they remain on the agenda. 

• S.2.5. (later amended and renumbered as S.2.5.2.) was adopted as a nonretroactive requirement 

taking into consideration that the devices in service prior to adoption could not meet this 

requirement.

• In the justification of this item the submitter asserts that “costly industry-wide retrofits of 

existing, functioning multi-use equipment” are required. S.2.5.1. and S.2.5.2. were adopted as 

a nonretroactive requirements to prevent this. 

• The weights & measures community should carefully consider the impact of making S.2.5.1. 

retroactive as it was adopted in 2019 with an effective date of January 1, 2021. There may be 

devices that cannot comply with this requirement which would need to be retrofitted if this 

item is adopted as proposed. 
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NIST OWM Executive Summary for LPG-24.2 – S.2.5. Zero-Set-Back Interlock. S.2.5. Zero-SetBack Interlock

• A search of the NCWM website indicates that there are various retail motor-fuel devices 

designed to dispense LPG that have an NTEP CC. Those installed after 1/1/2017 are required 

to have a zero-set-back interlock.

• Zero set-back interlock prevents the facilitation of fraud in accordance with G-S.2. Facilitation 

of Fraud by ensuring a dispenser returns to zero before the next transaction can be initiated 

whether the transaction is initiated by trained service personnel or a customer filling their own 

vehicle.

• In the justification for OTH-24.1. the submitter acknowledges that not all propane powered 

vehicles have the K15 connection. Per the U.S. Department of Energy’s website “The National 

Fire Protection Association (NFPA) Code 58 (beginning with the 2017 version) requires all 

new vehicles to be equipped with the quick-release “Type K15” connector as of January 1, 

2020. The ACME QCC screw-on connector has been used since 1994 for both vehicles and 

bottle filling.”

• Those vehicles that have the older style connection may have no choice but to fill at a station 

that may not have a device that has a zero-setback interlock.

MLK – MILK METERS

NIST OWM Executive Summary for MLK-23.2 – Table T.1. Tolerances for Milk Meters

NIST OWM Recommendation: A review of this item by the Milk Meter Task Group will be useful. 

We agree with the regions that recommended this item remain Assigned to the Milk Meter Task Group, 

and when the task group meets the item should be fully vetted by industry and the weights and measures 

community. 

• The Milk Meter Task Group reviewed all the varying tolerances in NIST HB 44 for Milk meters. 

Instead of keeping a decreasing tolerance as the test draft increases, the Task Group is proposing 

that the tolerances, as included in the 2024 Interim Meeting Agenda for VTM-20.2 for milk 

meters, also be adopted in the Milk Meter code. 

• Aaron Yanker (Colorado) is listed on the NCWM website as the Milk Meter Task Group Chair 

When the Task Group meets, a review of the item to include a review from affected industry and 

weights and measures jurisdictions is recommended.

• NIST OWM recognizes the comment made by the submitter to consider blocking item MLK23.1 with VTM-20.2 and a comment to withdraw item MLK-23.1. VTM-20.2 was discussed by 

the Milk Meter Task Group which included comments from industry and weights and measures 

jurisdictions and also appeared as a voting item on the S&T agenda. If the items are combined, a 

recommendation to withdrawn MLK-23.2 may affect VTM-20.2. 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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HGM – Hydrogen Gas-Measuring Devices

NIST OWM Executive Summary for NIST HGM-23.1 – UR.3.8. Safety Requirement

NIST OWM Recommendation: OWM has no recommendation until additional data is submitted.

• It has not been part of the weights and measures standards development process to include 

prescriptive safety requirements into handbook legal metrology standards.

• The dispenser’s design features regardless of their function should not affect the metrological 

integrity of the equipment.

• Traditional fueling applications have established mechanisms to address the safety features of 

dispenser installations not typically within the scope of the weights and measures authority.

• Groundwork is not outlined in the proposal detailing key elements that must be established for 

an SAE J2601 verification program and what standards if any apply to equipment in operation 

before the effective date.

• NIST OWM looks forward to the reporting from CA DMS and CARB as well as any updates 

from the submitter to clarify the types of test data available that are the result of compliance 

testing to the SAE J2601 standard. 

EVF – Electric Vehicle Fueling Systems

NIST OWM Executive Summary for EVF-24.1 – S.1.3. Mobile Device as Indicating Element for AC 

Chargers

NIST OWM Recommendation: Withdraw. The EVSE primary display must meet a more 

comprehensive set of requirements in multiple codes to provide clear, legible, and verifiable 

transaction information and other metrological data in an appropriate manner. 

• NIST OWM does not believe the proposed exceptions are appropriate without more detailed 

work to fully vet the permissible metrological features and functions for the wide range of 

software based remote devices to be recognized as the primary indicating elements for these 

commercial electrical energy measuring systems.

• The list of requirements referenced in the proposal (S.1.1., S.1.2., S.2.4.1, S.2.6, S.2.7, 

UR.1.1., and UR.3.1.) is not all inclusive of the paragraphs in NIST HB 44 applicable to 

indicating elements. There are additional requirements in Sections 1.10. General Code, 3.40.

Electric Vehicle Fueling Systems and 5.55 Timing Devices that apply to an EVSE display that 

is an integral part of the electrical energy dispensing system or when a single display is used by 

multiple EVSEs. Therefore, additional accompanying requirements need to be developed for 

clarity and to fully recognize the proposed options for primary displays.

• It was suggested prior to the code’s adoption in 2016, to identify those paragraphs which are 

posing difficulties for some manufacturers to meet and possibly making those paragraphs nonretroactive, with an eventual sunset date, rather than proposing an exception to the entire code.
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-24.1 – S.1.3. Mobile Device as Indicating Element for AC 

Chargers

• Likewise, OWM also suggested that exceptions are sometimes made for certain applications 

which are able to meet a requirement in a different way through other mechanisms such as a 

contract or other price agreement or fleet sales.

• An additional concern, with regard to equity, is that companies have spent money to comply 

with display requirements and after 2024 would be competing with a population of existing 

noncompliant equipment and new equipment which will not have to be equipped in the same 

manner with a primary display.

• The proposal is unclear if the devices running those apps are a necessity for the operation of 

the charging equipment although the proposal specifies the location of the handheld device or 

vehicle as “being in the immediate vicinity of the EVSE” and yet there is no mention of their 

availability over the entire course of the transaction given a session can take twenty minutes or 

multiple hours to complete.

• The open-ended nature of the types of devices that fall under this category means a wide 

variety of handheld devices or vehicles would be part of the type evaluation process where 

their accuracy and clarity become more critical to the measurement transaction.

• If they are the only EVSE primary display these newly recognized devices will be the means 

for accessing the device/system metrological security information which can be sizable, and 

determining fuel quantity totals.

• With some further work “Apps” installed on a mobile device might provide the best 

opportunity for allowing for innovation since there is a mechanism for reviewing the display 

provided by the app and ensuring its operation provides the necessary information. 

• The vehicle user interface, on the other hand, is somewhat problematic. They can vary from 

manufacturer to manufacturer and will undoubtedly change from year to year. How will the 

operator or regulatory official verify transaction information if vehicle user interface is the 

only means available for verification of this information? Will drivers be asked to voluntarily 

assist in inspections and complaint investigations, or will a car be provided as part of the 

official’s tool kit? The code will need to address this, and it will be necessary to ensure type 

evaluation can adequately address this. 

• How would the overall provisions of the General Code regarding legibility, clarity, and 

appropriateness of indications be applied when there is no display unique to a given EVSE onsite? The code addresses the EVSE as the intended point at which commercial measurements 

of electrical energy and related time fees are being made rather than the handheld device or 

EV. 

• Will there be unique or common vulnerabilities to factors such as levels of service, 

temperature, connectivity, etc. For traditional vehicle fuel dispensers and other alternative 

vehicle fuel dispensers weather and normal wear issues are managed through equipment and 

station design and maintenance programs.
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-24.1 – S.1.3. Mobile Device as Indicating Element for AC 

Chargers

• The submitter cites the concept of “Plug and Charge” that is part of ISO 15118 but has not 

provided information on the exact relevance/application to legal metrology requirements that 

apply. 

• Currently EVF-24.1 is a proposal for a new requirement but the letter-number paragraph 

designation of S.1.3. is already part of the existing code and is titled EVSE Units. Does the 

submitter intend the proposal to replace existing code; be part of indicating element 

requirements already included in the code; or have a new letter-number designation? 

NIST OWM Executive Summary for EVF–24.2 – S.2.7. Indication of Delivery, N.3.2. Accuracy 

Testing, and T.2.1. EVSE Load Test Differences Tolerances

NIST OWM Recommendation: Voting to allow fundamental requirements such as accuracy to be 

met uniformly across the marketplace. 

• The proposal modifies the 2028 enforcement date to become 2025 for DC Systems (1) 

automatic display of the start at zero and the final quantity of the electrical energy delivery, (2) 

performance test procedures, and (3) associated test tolerances. 

• The 2028 enforcement dates were adopted July 2022 as part of an emergency agenda item to 

make the NIST HB 44 EVFS Code permanent and in response to a lack of test equipment.

• The lack of access until 2028 to fundamental requirements, such as these for indications, 

accuracy tests, and tolerances, might possibly lead to nonuniformity in the application of those 

three sections of the EVFS code. 

• Paragraph G-A.3. Special and Unclassified Equipment exists for use by jurisdictions wishing 

to inspect and test existing equipment in order to approve it for commercial use. 

• We recognize that commercially available testing devices for high powered chargers are slated 

to become more widely available shortly and essential to verify DC fast charging equipment. 

• The Committee should correct the letter number designation for the test note to become N.3.2. 

not N.5.2. and the title of the tolerance requirement to become T.2.1. EVSE Load Test 

Tolerances not EVSE Load Test Differences. Should the submitter further modify the proposal 

to make the requirements enforceable to equipment only after the effective date, then the text 

should be changed to italic type. 

NIST OWM Executive Summary for EVF-23.4 – S.5. Markings and N.5. Test of an EVSE System

NIST OWM Recommendation: Developing to resolve the ambiguity of the language that prescribes 

the conditions for performing the test.
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.4 – S.5. Markings and N.5. Test of an EVSE System

• NIST acknowledges that although not reflected in the Item Under Consideration the submitters 

will recommend a return to the pre 2023 requirement for marking of the MCD not the MDA 

(i.e., S.5.2.(b)) to clarify the appropriate terminology to be used for specifying the EVSE 

manufacturer’s highest amperage load rating for operation of the equipment under test and to 

be marked on the device. 

• This proposal removes any reference to the feature used to determine the MDA percentage 

level achieved during accuracy tests and establishes a new MDA range for performing the light 

load test and when a vehicle is the test load for verifying EVFSs. 

• The 2023 proposal created a new separate test requirement initially for laboratory evaluations 

which are now specified solely for type evaluation; therefore a 2028 exemption would also be 

new text that requires being underscored to clearly designate the 2028 effective date as new 

language. 

• The 2028 effective date is confusing, is the intent that no testing at an approved brick and 

motor facility nor type evaluations can be carried out until January 1, 2028? 

• OWM notes that because of the 2028 enforcement date the NIST Handbook 44 General Code 

will continue to apply to existing equipment, including paragraph G-A.3. Special and 

Unclassified Equipment. Jurisdictions wishing to inspect and test existing equipment in order 

to approve it for commercial use would be left to use this provision. 

• A slight change is recommended for the agenda item’s title to include missing paragraphs 

S.5.2.(b) EVSE Identification and Marking Requirements and S.5.3.(d) Abbreviations and 

Symbols; joule and striking S.5. Markings to clarify these units of measurement are a part of 

this proposal. This would also assist the community in distinguishing this item from multiple 

other proposals that address other types of EVFS marking requirements.

• In May 2023 the EVFE Subgroup tasked its Test Procedure Subcommittee (TPS) to undertake 

the project of combining Items EVF-23.4 and EVF-23.7 into a single proposal. After input 

from the submitters of both proposals and other U.S. stakeholders, and multiple meeting 

deliberations (June through December 2023) the TPS arrived at a draft that combines elements 

of both proposals under EVF-23.4 that it will send to the EVFE Subgroup mid-December 2023 

for its consideration. Simultaneously the co-submitters agreed in late August to combine the 

desired elements from both proposals under a single agenda item and to also recommend 

withdrawing of EVF-23.7. 

• Multiple paragraphs appearing under the heading “Item Under Consideration” no longer reflect 

the exact wording or paragraph designations of these requirements as a result of actions which 

occurred during the 31JUL2023-03AUG2023 NCWM Annual Meeting. 

• The NIST Technical Advisor to the TPS has noted there are five places in the submitters’ 

August 2023 alternate test procedures and new definitions needing further refinement to ensure 

uniform interpretation and application of the test procedure requirements (see the NIST OWM 

Detailed Technical Analysis). NIST OWM recommended further edits to clarify test 

procedures where requirements include the terms/phrases: (1) maximum power level; (2) using 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.4 – S.5. Markings and N.5. Test of an EVSE System

the test equipment available; (3) current levels should be separated to the extent the test 

equipment will allow; (4) installed under optimum conditions (in the definition of MCD); and 

(5) determined by the signal or communication between the EVSE and EV or test equipment 

(in the definition of MDA). The 2028 effective date is confusing, is the intent that no testing at 

an approved brick and motor facility nor type evaluations can be carried out until January 1, 

2028? 

NIST OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking 

Requirements and T.2. Tolerances

NIST OWM Recommendation: Developing to allow for deliberations on the enforcement dates and 

establishing parameters for use of an electronic display.

• Initially NIST OWM suggested a review of Items EVF-23.5 and EVF-23.6 where both items 

propose changes to marking and accuracy requirements in NIST Handbook 44. 

• OWM has given thought to how we might assist the Committee and the Community in 

addressing these items in arriving at a single proposal that would meet the needs of the 

submitters of both items and other stakeholders. 

• OWM believes this proposal (Item EVF-23.6) and the alternative recommended in Item 

EVF- 23.5 both required more work and vetting as suggested by two of the four regional 

associations. Voting Item EVF-23.6 needs further refinement. 

• OWM believes this preliminary work would have been done in the USNWG SG as 

recommended during the WWMA meeting and recommended the Committee designate these 

items as Developing in 2023 and asked the SG for assistance in vetting the proposals. 

Adoption should occur only after fully vetting proposals by the entire community as the 

submitter(s) may be too close to the subject or take too wide a berth in the development of new 

or modification of existing requirements resulting in either overlooking or oversimplifying the 

lessons learned in the marketplace which can lead to misreading the complexities of 

commercial applications which have necessitated legal metrology controls. It has been 

reported that when addressing the level of confidence that buyers and sellers have, and the 

accuracy with which these transactions are performed that: The consumer has no way to verify 

the accuracy of the transaction and must rely on the accuracy of the fuel dispenser.

• In anticipation that the Committee believed there was an urgent need to move one of these 

proposals forward, OWM encouraged the Committee to use the proposed language in Item 

EVF-23.5 as a starting point to ensure clarity and understanding of the final language. 

o Having well-defined tolerances with clear and understandable effective dates is essential.

o Defining tolerances that are enforceable in the specific device codes is also preferable to 

the alternative of having jurisdictions use the provisions of the General Code to implement 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking 

Requirements and T.2. Tolerances

tolerances suitable for the application since this has the potential for non-uniform 

application across the country.

• As shared in its comments in Item EVF-23.5, OWM believes the proposed changes in Item 

EVF-23.5 was much clearer in language, format, and application and are closer to language 

agreed to by the USNWG SG for ballot in June 2022 than are the proposed changes in Item 

EVF-23.6. OWM is aware of the Committee’s decision to withdraw Item EVF-23.5.

o The USNWG EVFE Subgroup gained momentum as the result of a June 2022 ballot in 

which the group agreed to move forward to recommend a wider tolerance of 5 percent 

only for DC systems installed before 2024 that must bear accuracy markings while 

maintaining for AC systems a 1 percent Acceptance Tolerance/2 percent Maintenance 

Tolerance and the tighter tolerance would also apply to post 2024 DC systems.

o The language from the June 2022 ballot is included in OWM’s detailed analysis below 

and in the history on Item EVF-23.5.

• There were differences between the language recommended in that June 2022 SG ballot and 

that proposed in Item EVF-23.6. The language recommended in the June 2022 ballot:

o Permitted DC devices installed before 2024 to have a wider tolerance if they were clearly 

marked to designate their accuracy.

o Included a wider tolerance of 5 % for DC systems installed before 2024 when accuracy is 

marked, which several OEMs identified as achievable. Note: The June 2022 SG’s 

language did not include an exemption for DC systems from accuracy tolerances up 

through 2028 to sunset in 2034 and was a more suitable option.

o Recognized the EVFE Subgroup would further refine the requirement’s text. 

• OWM acknowledged a Florida, Electrify America, Tesla, EVgo, and Siemens’ October 15, 

2022, letter sent to the S&T Committee regarding EVF-23.6 and a June balloted proposal of 

the USNWG EVFE Subgroup (SG). OWM submitted the following clarifications regarding 

this letter to the S&T Committee.

o NIST OWM, as convenors of the EVFE SG, sent a response to the Committee indicating 

that although the results of the Subgroup’s June 2022 ballot indicate the group’s support 

for modifications to tolerances and marking requirements this should not be construed as 

supporting the specific changes proposed in EVF-23.6.

o There are some key differences between the Subgroup’s June balloted proposal and EVF23.6. Specifically, the Subgroup’s proposal does not include two different retroactive 

dates and differs in the magnitude of the tolerances and specific conditions under which 

they would apply, the permissible format required for markings (which are not indelible, 

do the submitters have a label or electronic only in mind?) and reference to certification. 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking 

Requirements and T.2. Tolerances

The convenors of the Subgroup will continue to provide written and verbal input as 

explicitly directed by the group. 

• It also is written that the components of the weights and measures infrastructure help to ensure 

the accuracy and validity of commercial transactions based upon weight, measure, or count and 

to ensure that the quality of products meets required quality standards. Another purpose of 

these components is to ensure consumers are informed so that they can make value 

comparisons. A robust infrastructure ensures equity in the marketplace, meaning that 

consumers receive the correct quantity and quality of products and services for which they pay, 

and businesses receive fair payment for the products and services that they deliver. By 

ensuring that they operate according to a consistent set of weights and measures standards and 

practices, businesses are also protected from unfair competition.

• Below are some additional comments for the Committee and other stakeholders to have 

considered in their review of Item EVF-23.6:

o Use of the terms “load” and “accuracy” should be reviewed for consistency in their use in 

the titles of the two T.2. subparagraphs.

o The community should revisit past national discussions on the electronic formatting of 

required marking information and also consider April 2023 comments raised in the EVFE 

Subgroup ballot for specifying a minimum time for the duration of the displayed accuracy 

statement and the statement be capable of being viewed in entirety prior to use of the 

EVSE. 

• Adoption should occur only after fully vetting proposals to modify fundamental requirements 

such as those that impact accuracy, transparency, or that ensure fair competition to:

o avoid unforeseen consequences;

o ensure stakeholders have the appropriate tools needed for this new device application;

o discourage nonuniformity which can have a disruptive influence on the marketplace; and

o take corrective action on discovering any gaps/oversight in modifications to the sevenyear-old legal metrology requirements.

• Where commercial equipment is known to operate at dual tolerances the proposed marking and 

performance requirements should be retroactive. Although there is likely to be some 

discussion as to what nonweights and measures agencies designate as a “public” station; the 

DOE EERE Alternative Fuels Data Center provides the number and location 

(stations/ports/charging levels) of alternative fueling installations in each state on the EERE 

website available at: https://afdc.energy.gov/stations/states.

• NIST OWM acknowledges that the EVFE Subgroup met on December 8, 2022 and March 2 

and 6, 2023 to address proposals under consideration for the 2023 standards development cycle 

and the SG provided a July 12, 2023 memorandum on its position in support of the Item Under 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking 

Requirements and T.2. Tolerances

Consideration for Item EVF-23.6 as it appears in the Committee’s Interim Meeting Report 

(PUB 16).

• NIST OWM encourages the community's participation in the USNWG EVFE Subgroup which 

began its work in 2012 and whose work resulted in NIST HB 44 3.40 EVFS Code's adoption in 

2015. The Subgroup has reviewed the four paragraphs that appear in multiple 2023 proposals 

that address: (1) dual EVSE tolerances (2.0 percent or 5.0 percent [DC EVSEs]); (2) new 

EVSE markings required for the wider tolerance in the marketplace; and (3) corresponding 

accuracy test procedures.

• There are several dates referenced in proposed EVF-23.6 paragraph T.2.2. Tolerances that 

conflict and OWM believes will create confusion for those implementing the proposed 

requirements.

o The statement adopted by the NCWM in July 2022 exempting DC devices from any 

tolerance requirements until 2028 remains in the proposal, yet there is a date of 2024 in 

both the proposed paragraph T.2.2.(a) and paragraph T.2.2.(b) which specifies 

requirements for DC devices installed prior to 2024. This is confusing and widens the 

gap: (1) in time delays in the application of tolerances in what will be a dual tolerance 

marketplace for DC systems (2) that encourages nonuniformity in equipment 

performance and (3) in the timely marking of information for consumer awareness.

o Proposed paragraph T.2.2.(a) references a sunset date of 2034, yet there is still a statement 

referring to a 2028 date, creating a conflict. Additionally, the 2034 date is 6 years after 

the 2028 date that was adopted by the NCWM in July 2022. The rationale for establishing 

a sunset date of 2034 for the entire country, given the pace at which technology has 

already advanced, is nineteen years after the tentative code was first adopted by the 

NCWM.

• There were differences between the language recommended in that June 2022 SG ballot and 

that proposed in Item EVF-23.6. The language recommended in the June 2022 ballot:

o Permitted DC devices installed before 2024 to have a wider tolerance if they were clearly 

marked to designate their accuracy.

o Included a wider tolerance of 5 % for DC systems installed before 2024 when accuracy is 

marked, which several OEMs identified as achievable. Note: The June 2022 SG’s 

language did not include an exemption for DC systems from accuracy tolerances up 

through 2028 to sunset in 2034 and was a more suitable option.

o Recognized the EVFE Subgroup would further refine the requirement’s text. 

• OWM acknowledged a Florida, Electrify America, Tesla, EVgo, and Siemens’ October 15, 

2022, letter sent to the S&T Committee regarding EVF-23.6 and a June balloted proposal of 

the USNWG EVFE Subgroup (SG). OWM submitted the following clarifications regarding 

this letter to the S&T Committee.
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.6 – S.5.2. EVSE Identification and Marking 

Requirements and T.2. Tolerances

o NIST OWM, as convenors of the EVFE SG, sent a response to the Committee indicating 

that although the results of the Subgroup’s June 2022 ballot indicate the group’s support 

for modifications to tolerances and marking requirements this should not be construed as 

supporting the specific changes proposed in EVF-23.6.

There are some key differences between the Subgroup’s June balloted proposal and EVF-23.6. 

Specifically, the Subgroup’s proposal does not include two different retroactive dates and 

differs in the magnitude of the tolerances and specific conditions under which they would 

apply, the permissible format required for markings (which are not indelible, do the submitters 

have a label or electronic only in mind?) and reference to certification. The convenors of the 

Subgroup will continue to provide written and verbal input as explicitly directed by the group.

Due to time constraints the Subgroup has not met on this issue in 2023.

• Should the community agree to the numerical designation of an Accuracy Class for DC 

systems which meet the wider tolerance, then additional requirements should be developed to 

include: (1) a new standardized accuracy class table; (2) requirements specifying the 

appropriate “Accuracy Class” identifier; and (3) requiring the accuracy classification be 

marked on the EVSE.

• Notice to consumers will need to adequate as to the information they provide that accuracy 

assurance varies from one site to another. 

NIST OWM Executive Summary for EVF-23.7 – N.1. No Load Test, N.2. Starting Load Test N.5.2. 

Accuracy Testing, and Appendix D: Definitions– maximum deliverable amperes

NIST OWM Recommendation: Withdraw due to work in progress nearing completion to incorporate 

this proposal into EVF-23.7.

• Test procedures are not solely written to the operational characteristics or particular design of 

one test apparatus. Test procedures should encompass operational conditions over the course 

of the entire transactions in the marketplace. Test points should fall within the rated minimum 

up through the maximum operational ranges specified by the manufacturer for the EVFS under 

normal conditions of commercial use. 

• Observe this proposal removes any reference to the feature used to determine the MDA 

percentage level achieved during accuracy tests and establishes a new MDA range for 

performing the light load test and when a vehicle is the test load for verifying EVFSs; whereas 

other proposals recommend the establishment of a new laboratory test in addition to field test 

procedures.

• The EVFS test standard must be fit for purpose or appropriate and suitable (this might be 

demonstrated by data) in its design, capacity, and accuracy; and would allow for replication of 

the manner in which the EVSE is used in commerce. The test standard used to verify an EVSE 

must also meet the NIST HB 44 Appendix A Fundamental Considerations for a test apparatus. 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for EVF-23.7 – N.1. No Load Test, N.2. Starting Load Test N.5.2. 

Accuracy Testing, and Appendix D: Definitions– maximum deliverable amperes

• Therefore, with a decade of experience with EVFSs having gone through type evaluation (i.e., 

CADMS) and test equipment designed to verify both AC and DC systems and the laboratory 

community closing in on filling the last gaps in the weights and measures infrastructure for 

EVFSs; it is important and necessary that all stakeholders (EVSE/test equipment 

manufacturers, type examiners, and regulators) reach a consensus on test procedures. 

• Is this a proposal to renumber paragraph N.5. Accuracy Testing to become N.5.2.1.? The 

proposal does not show paragraph N.5.2 in entirety, is the submitter proposing to remove the 

2028 enforcement date? Please be advised that as a result of actions which occurred during the 

31JUL2023-03AUG2023 NCWM Annual Meeting modifications to NIST HB 44 3.40 were 

adopted and resulted in the renumbering of the test notes (N.), the N.5 test procedure 

paragraphs were renumbered to become N.3. Additionally, that action by the NCWM deleted 

and no longer recognizes paragraphs N.1. No Load Test and N.2 Starting Load Test as part of 

the minimum test procedures for EVSEs. 

• The proposal removes the No Load Test and Starting Load Test but does not do the same for 

the tolerances applicable to these tests in paragraphs T.5. and T.6, respectively. 

• For clarity the “meaning portion” of a definition should not include the term or parts of the 

term it is defining nor cite one of the many code paragraphs where the term is used because the 

appearance can be the term is unique to that sole paragraph. Therefore, the term’s definition 

should include reference to the EVFS Code in brackets (i.e., [3.40] at the end of the definition 

rather cite a single code requirement or paragraph. The EVFS is a permanent code and 

definitions applicable to the code should be included in Appendix D—Definitions. 

• In May 2023 the EVFE Subgroup’s Test Procedures Subcommittee (TPS) was tasked with 

working through a May 2023 version of the test procedures addressed in Item EVF 23.4. This 

latest modified version of the test procedures is the result of the collaborative effort of the 

submitters of both test procedure proposals in Items EVF 23.4 and EVF-23.7. TPS discussions 

about modifications of the test procedures and defining new terms having special and openended meaning were focused on input from stakeholders (type and routine field testing), the 

NCWM, regional weights and measures associations, and NIST OWM. Based on the TPS's 

May through December 2023 deliberations the TPS has agreed to forward a combined proposal 

derived from both EVF-23.4 and EVF-23.7 for the EVFE Subgroup’s consideration.

GMA – Grain Moisture Meters 5.56 (a)

NIST OWM Executive Summary for GMA-19.1 – Table T.2.1. Acceptance and Maintenance 

Tolerances Air Oven Method for All Grains and Oil Seeds

NIST OWM Recommendation: NIST OWM supports the Grain Analyzer Sector’s decision to 

Withdraw this item recognizing that if additional data is received the proposed tolerance changes may 

be resubmitted for consideration. 

• During the NTEP Grain Analyzer (GA) Sector 2019 meeting, the Sector reviewed data from 

Arkansas for Long Grain Rough Rice (LGRR) and other grains. The data showed that the 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

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NIST OWM Executive Summary for GMA-19.1 – Table T.2.1. Acceptance and Maintenance 

Tolerances Air Oven Method for All Grains and Oil Seeds

proposal to tighten the acceptance and maintenance tolerance may not be appropriate for all 

grain types. The original data presented and used as a basis for the proposal applied to corn 

and soybeans. After reviewing the data, the Sector decided to collect inspection data from 

across the country. An industry representative offered to assist with data analysis and along

with the NIST representative will work in producing the inspection data needed for the 

analysis. A request for State participation will be sent to State weight and measures. The 

Sector requests that this remain a Developing Item as they move forward in evaluating 

additional data.

• North Carolina submitted the requested grain data for review. Field meter inspection data from 

the state of North Carolina for years 2017 to 2019 was examined and comprised over 3300 

records each usually averaged 3 commodity drops on UGMA and Non-UGMA meter types.

While only one state’s data cannot be considered representative of all the other states, the 

results provide indications of trouble with decreased tolerances on both UGMA and NonUGMA meter types.

• The Grain Analyzer Sector has not received additional data needed to further assess their 

proposed tolerances changes to NIST HB 44, Section 5.56(b) The GA Sector will keep this as 

an open item on their Sector agenda, but as the submitter of this item, the GA Sector 

recommends that this item be withdrawn. If or when additional data is received, the Grain 

Analyzer Sector may resubmit the item.

OTH – Other Items

NIST OWM Executive Summary for OTH-16.1 – Electric Watthour Meters Code Under 

Development

NIST OWM Recommendation: Informational with an upgrade in status should the stakeholders 

reach agreement by March 2024.

• The title of this Item should read “Non-Utility Electricity-Measuring Systems (NUEMS) –

Tentative Code”.

• Most members supported the proposed language as it currently appeared in the 2023 S&T 

Agenda (NCWM Pub. 16), although regulatory members of the SG disagreed with the 

proposed language. 

• In addition, the regulatory members provided a detailed list to the WHE SG of their concerns. 

These concerns are noted in the letter that NCWM received from the California Agricultural 

Commissioners and Sealers Association (CACASA) (dtd. June 29, 2023) and posted under the 

NCWM S&T Supporting document website.

• The WHE SG attempted to address the regulators and CACASA concerns. They made 

headway in addressing those concerns and they appear in the Crosswalk below. 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

26

NIST OWM Executive Summary for OTH-16.1 – Electric Watthour Meters Code Under 

Development

• The Crosswalk below, provides updates of items that appear in the 2023 S&T Annual Agenda 

(Pub. 16). They represent changes the WHE SG voted on to move forward to the S&T 

Committee for consideration. Due to limited time, the WHE SG was not able to address all the 

items, and the work continues. 

NIST OWM Executive Summary for OTH-24.1 – Appendix D, Definitions: liquefied petroleum gas 

retail motor-fuel device.

NIST OWM Recommendation: Withdrawn

• If the item remains as proposed it should be withdrawn or be assigned a developing status. 

• The reference to Section 3.32. at the end of the definition should not be stricken. 

• OWM opposes limiting this definition to those devices that have a K15 nozzle as it is only 

required on “self-service engine fuel dispensers” per NFPA 58, 6.28.5.2. 

• Currently all dispensers used to deliver LPG as a motor vehicle fuel installed after January 1, 

2017 are required to have a zero-setback interlock as required on devices that dispense other 

types of fuels into motor vehicles. 

• A search of the NCWM website indicates that there are various retail motor-fuel dispensers 

designed to dispense LPG that have an NTEP CC and are suitable for this purpose. Those 

installed after January 1, 2017 are currently required to have a zero-setback-interlock.

• This item should be blocked with LPG-24.1 and LPG-24.2 if they remain on the agenda. 

NIST OWM Executive Summary for OTH-24.2 – Appendix D, Definitions: National Type 

Evaluation Program (NTEP) and Certificate of Conformance (CC)

NIST OWM Recommendation: Voting with the following suggested edits:

• In the proposed definition of Certificate of Conformance (CC) OWM suggests the following 

editorial changes: 

• Replace “testing” with “evaluation” as labs do more than just test devices.

• Replace “a Participating” with “an authorized” or similar terms to recognize that some 

CC’s will be issued by the NCWM NTEP lab.

• Replace “test procedures” with “relevant provisions” as Pub 14 includes procedures 

for evaluation other than test procedures.

• Remove “which the certificate holder maintains in active status under the National 

Type Evaluation Program (NTEP)” as inactive certificates are still recognized.
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

27

NIST OWM Executive Summary for OTH-24.1 – Appendix D, Definitions: liquefied petroleum gas 

retail motor-fuel device.

• Replace “By maintaining the Certificate in active status, the Certificate holder 

declares the intent” with “An active Certificate represents the intent of the holder” and 

add “approved” before “type” in this sentence.

• Remove the sentence ”Some certificates may be designated as inactive.” as it is 

unnecessary.

• The definition then would appear as follows:

Certificate of Conformance (CC) – A document issued based on evaluation by an authorized 

laboratory. The document constitutes evidence of conformance of a model or models of a 

particular device, measurement system, instrument, or element that positively identifies the 

design with the requirements of this document, NIST Handbook 44, “Specifications, 

Tolerances, and Other Technical Requirements for Weighing and Measuring Devices,” and the 

relevant provisions contained in NCWM Publication 14. An active Certificate represents the 

intent of the holder to continue to manufacture or remanufacture the device consistent with the 

approved type and in conformance with the applicable requirements. A device is traceable to an 

active CC if: (a) it is of the same type identified on the Certificate, and (b) it was manufactured 

during the period that the Certificate was maintained in active status. For manufacturers of 

grain moisture meters, maintenance of active status also involves annual participation in the 

NTEP Laboratory On-going Calibration Program, OCP (Phase II). An inactive Certificate of 

Conformance is a Certificate which was previously active, but the devices are no longer being 

manufactured for commercial applications subject to local regulations or laws. However, 

devices already manufactured, installed or in inventory, but not yet sold, may be used, sold, 

repaired and resold under inactive Certificates of Conformance.

• In the definition of National Type Evaluation Program (NTEP) replace the term “operated” 

with “administered” as this is consistent with the description in Pub 14 Administrative Policy.

Item Block 1 (B1) Transfer Standard

NIST OWM Executive Summary for Item Block 1 (B1) – Transfer Standard

NIST OWM Recommendation: Voting

• OWM supports amending these items to replace the term “Field Standard Meter” with 

“Transfer Standard”, which is now a defined term in NIST Handbook 44 and amend the 

language to be consistent with similar paragraphs in other sections.

• Each of these Items Under Consideration in the S&T portion of Pub 15 should be edited to 

reflect the correct format prescribed by NCWM to identify changes to be made to the 

handbook as shown under the Item Under Consideration in this analysis as the intent is to 

amend these paragraphs and not replace them. 
NIST OWM Executive Summary

2024 NCWM Interim S&T Agenda Items 

28

NIST OWM Executive Summary for Item Block 1 (B1) – Transfer Standard

• In addition, in the S&T portion of Pub 15, the description in the Item under Consideration for 

MFM-24.1 specifies the item will amend the “Handbook 44 Milk Meters Code”. This should 

be edited to reflect that this item is intended to amend the Mass Flow Meter Code of NIST 

Handbook 44.