JUNE 2007 

Device Inspection - Where to Find Help 

By Rick Harshman 

A proper device examination is one in which all applicable NIST Handbook 44 (HB-44) 

requirements have been properly applied. Approval of a commercial weighing or 

measuring device is appropriate only when it has been determined through complete and 

proper examination that the device conforms to all applicable HB-44 requirements. This 

includes not only compliance with accuracy or performance requirements, but also 

design, maintenance, and user requirements. The importance of verifying that weights 

and measures equipment comply with all applicable HB-44 requirements is imperative, as 

is knowing the resources available to gain knowledge on the correct interpretation and 

application of HB-44 requirements. 

 

Why is it that many field officials tend to place a greater emphasis on verifying the 

performance and accuracy of devices (i.e., making certain they have followed proper 

testing procedures and correctly applied applicable tolerances) than on the inspection of 

devices (i.e., verifying compliance with design, maintenance, and user requirements)? 

Although device accuracy is an extremely critical factor in the final establishment of 

accurate weighing or measuring results, it is of no greater importance, in that regard, than 

is proper design, maintenance, and use of a device. After all, final measurement results 

are affected by more than device accuracy alone. Any number of deficiencies relating to 

device design, maintenance, and use can also affect final results. Thus, placing a greater 

emphasis on testing versus inspection of devices is unacceptable. It is only through 

complete and accurate application of all applicable requirements that the “purpose” of 

HB-44 technical requirements can properly be achieved. 

 Purpose of HB-44 Technical Requirements 

(Excerpt from the Introduction of HB-44) 

Weights and measures administrators and field officials alike share a key responsibility of 

ensuring that all applicable HB-44 requirements are applied and are applied correctly. 

The consequences of failing to take this responsibility seriously can be severe, especially 

if unfair enforcement actions are taken based upon examination results that are either 

unreliable or incomplete. Also, if deficiencies are going unnoticed, they have the 

potential of resulting in extreme financial loss (or gain) to the device owner or his/her 

customers. What steps can field officials take to help ensure they are conducting 

complete device examinations? What resources are available to help field officials gain 

The purpose of these technical requirements is to eliminate from use, weights and 

measures and weighing and measuring devices that give readings that are false, 

that are of such construction that they are faulty (that is, that are not reasonably 

permanent in their adjustment or will not repeat their indications correctly), or that 

facilitate the perpetration of fraud, without prejudice to apparatus that conforms as 

closely as practicable to the official standards.
the knowledge necessary to enable them to apply all requirements and test procedures 

properly? What actions can administrators take to best support field officials in their 

efforts? 

Field officials must possess a thorough understanding of all requirements and test 

procedures applicable to each device type they will be examining to enable them to apply 

those requirements and test procedures properly. They must also be familiar with the 

correct operation of the devices they examine, including the purpose and function of any 

operational controls or features that may exist on those devices. Service personnel, too, 

must have knowledge of applicable requirements to enable them to correctly service 

equipment so that it complies with applicable requirements. There are plenty of 

resources available to help field officials and service personnel gain the necessary 

knowledge in this regard. The following bulleted list describes many of the resources 

made available by NIST: 

NIST Examination Procedure Outlines (EPO’s): NIST WMD has developed EPOs for 

most of the more common device types to make it easy for field officials to ensure they 

are conducting complete device examinations. Each outline describes the minimum 

examination preceding official action and is not intended to preclude officials from 

conducting additional testing or repeating tests as part of the examination process should 

the inspector determine additional testing is warranted. Thus, by consulting the 

appropriate EPO corresponding to the device being examined, and applying all of the 

requirements outlined, field officials can be assured they have performed a minimum 

acceptable examination. They may also repeat tests or conduct additional tests as needed. 

It is important to note that the EPO’s are intended to reference every HB-44 requirement 

that could possibly apply to a particular device type used under any application. 

However, since some operational features of a device may be dependent upon a particular 

application, all requirements referenced in an EPO may not apply to every device of the 

type being examined. Service companies may also find the EPOs of use in identifying 

those tests and criteria that will be applied by the weights and measures official. 

Note: Although NIST Handbook 112 (HB-112) contains all of the EPOs that WMD had 

developed as of 2002, WMD has since developed EPOs for some additional device types, 

which are not included in HB-112. Additionally, many of the EPOs that are in HB-112 

have recently been updated by WMD to reference requirements contained in the 2007 

edition of HB-44. For this reason, it is recommended that anyone seeking the most 

current version of an EPO contact WMD. Once WMD has completed the updates to all 

of the EPOs, they will be made available on WMD’s website. 

 

• NIST Training Seminars: Members of WMD’s Legal Metrology Devices Group 

(LMDG) routinely present training seminars to officials and service personnel on proper 

device examination. The specific types of devices covered and the locations of these 

seminars are based upon the training needs of the various states, in particular, those states 

whose state director responds to WMD’s annual request for input on training needs. 

Seminar duration typically ranges from approximately one to five days depending upon 

the topic and the degree of instruction requested. Topics and locations of upcoming 
NIST training seminars are listed regularly in this newsletter (i.e., Weights & Measures 

Quarterly newsletter) under the heading “Calendar of Events.” Many of the presentations 

and much of the course material from recently completed NIST training seminars is 

currently available online. To access this information, go to the NIST WMD website at 

www.nist.gov/owm and click on “NIST/Weights and Measures Training.” Then select 

the appropriate “interface link” to access the desired training module. 

• Inspector Manuals: Inspector manuals provide detailed information regarding 

the history, purpose, and application of HB-44 requirements as they relate to the 

particular device type for which the manual applies. These manuals also provide 

information about the design, application, and use of the device. These manuals are 

extremely useful in determining correct interpretations and applications of HB-44 

requirements as they relate to a particular type of device. Each manual is subdivided 

into several chapters allowing information to be located quickly and easily. Inspector 

manuals have been developed for many different device types. Some are currently 

available online and included in the course material currently offered on the 

“NIST/Weights and Measures Training” page of WMD’s website. To access the manuals 

available online, click on the appropriate “interface” button from the “NIST/Weights and 

Measures Training” page for the device type desired. Then download the chapters 

needed by selecting the “PDF” or “Word” format. To inquire about other Inspector 

manuals not available online, contact WMD’s Rick Harshman using the contact 

information provided at the end of this article. 

• Weights & Measures Quarterly Newsletter: Members of the LMDG regularly write 

technical articles relating to proper device examination, which are often featured in 

WMD’s Weights & Measures Quarterly newsletter. Many of these articles list and 

explain proper procedures to be used, provide correct interpretations of HB-44 

requirements, and offer other relevant information a field official would need to know to 

perform a proper device examination. Information in these articles can also be of use to 

weights and measures administrators in understanding the resources and information 

required by the field official. Likewise, service companies can gain benefit from this 

information because it provides better understanding of the requirements and test 

procedures officials should be applying to equipment in the field. An index of these 

technical articles by device type is available on WMD’s website to enable users to easily 

locate related articles appearing in previous editions of this newsletter. To access the 

index, go to WMD’s homepage and click on “Weights and Measures Quarterly 

Newsletter Archive” listed under the heading “Publications.” 

• Annual Reports of the National Conference on Weights and Measures (NCWM): 

The annual reports of the Committee on Specifications and Tolerances (S&T Committee) 

provide background information and related discussions on proposed changes to NIST 

HB-44. This information is of great benefit when trying to establish the intended 

application or a correct interpretation of an existing HB-44 requirement. Each Annual 

Report of the NCWM is published by NIST as a Special Publication. The Annual 

Reports of all of the National Conferences on Weights and Measures (i.e., from 1905 – 

2006) have been incorporated onto a single DVD made available by NIST. This DVD 
includes a search feature allowing information to be searched in a variety of different 

ways. 

• Field Manuals: Field manuals are intended to provide more information and 

instruction than is currently available in the EPOs, yet not so much information as to 

diminish their usefulness as a tool for field officials. Though not posted on the WMD 

website, a few older field manuals including NBS Handbook 137, Examination of 

distance measuring devices, and NBS Handbook 117, Examination of vapor-measuring 

devices for liquefied petroleum gas are available. Members of the LMDG are in the 

process of developing additional field manuals for vehicle scales, belt-conveyor scales, 

and grain moisture meters. 

• Technical Support from NIST Staff: WMD’s staff of “technical experts” is 

available Monday through Friday, 8:30 a.m. to 5:00 p.m. (ET) to answer questions and 

provide technical assistance encompassing a broad range of weights and measures issues. 

WMD is organized into four program areas as follows: State Laboratory Program, 

Device Technology Program, Laws and Metric Program, and the International Legal 

Metrology Program. It is recommended that inquiries relating to device inspection and 

HB-44 issues be directed to an appropriate expert in the LMDG, which is considered part 

of the Device Technology Program. A list of each LMDG member’s technical 

responsibilities related to device inspection is included in the table below. To talk with 

an expert, contact WMD at (301) 975-4004. 

NIST Weights and Measures Division 

Legal Metrology Devices Group 

Type of Information Who to Contact Telephone 301-975 + ext 

Publications

NIST Handbook 44, 

Specifications, Tolerances 

and Other Technical 

Requirements for Weighing 

and Measuring Devices

Tina Butcher, Steve Cook, 

Rick Harshman, Diane Lee 

Richard Suiter, Juana Williams

2196, 4003, 

8107, 4405, 

4406, 3989 

Measuring Devices

Loading-Rack Meters 

LPG Meters 

Mass Flow Meters 

Retail Motor-Fuel Dispensers 

 (Gas Pumps) 

Vehicle-Tank Meters 

General Metering Devices

Richard Suiter 

Tina Butcher 

Juana Williams

4406 

2196 

3989 
NIST Weights and Measures Division 

Legal Metrology Devices Group 

Type of Information Who to Contact Telephone 301-975 + ext 

Weighing Devices

Automatic Weighing 

Systems 

Belt-Conveyor Scales 

General Weighing Devices 

Vehicle & Railroad Track 

 Scales 

In-Motion Scales 

Load Cells

Steve Cook 

Juana Williams 

Rick Harshman 

4003 

3989 

8107

Other Devices

Animal Carcass Measuring 

Devices 

Richard Suiter 4406 

Grain Moisture Meters & 

NIR Protein Analyzers 

OIML R 59 Grain Moisture 

 Meters 

OIML TC 17/SC 8 Grain 

Protein Measuring 

Diane Lee 4405 

Multiple Dimension Measur-

 ing Devices Richard Suiter, Tina Butcher 4406, 2196 

Taximeters and Odometers 

OIML R 21 Taximeters Juana Williams 3989 

Note: WMD is currently in the process of reorganizing its website. Updated instruc 

tions for accessing the information below will be provided in a future edition of the newsletter once the reorganization is complete. 

In addition to the resources made available by NIST, a number of state and local weights 

and measures agencies also offer periodic training schools or seminars on device 

inspection. Besides covering basic device inspection, this training is often offered to 

keep officials up-to-date on new requirements being added or changes made to existing 

requirements in HB-44 and new developments in device technology. Training is also 

made available on occasion from equipment manufacturers, who often welcome the 

opportunity for weights and measures officials to participate in training they extend to 

their own employees or those involved with the distribution or service of their equipment. 

This training provides an excellent opportunity for field officials to learn the many 

operational features of new equipment and how that equipment complies with legal 

requirements. 

Field officials need to know their efforts are being supported by their superiors. 

Therefore, it is not only important for weights and measures administrators to 

communicate their desire for field officials to conduct complete and accurate device 

examinations, but it is also just as important that administrators continually demonstrate, 

through their actions, that they are genuinely committed to achieving this goal. There are 

many ways this commitment can and should be demonstrated. Below are some examples 

of actions that can be taken by administrators to help demonstrate this commitment: 
• Provide regular opportunities for field officials to participate in training designed to 

increase their knowledge of HB-44 requirements and the test procedures that apply to the 

various devices for which they are responsible for examining. 

• Make available to field officials all necessary reference material (e.g., EPOs, 

inspector manuals, access to technical newsletter articles, etc.). 

• Allow sufficient time for field officials to conduct complete and accurate device 

examinations. As officials gain experience in performing complete and accurate 

examinations, their speed can be expected to increase, thus reducing the amount of time it 

takes to perform complete examinations. 

• Monitor the inspection activities of field officials to ensure examinations are 

complete and accurate. Provide additional guidance and training as needed to achieve the 

goal that was communicated. 

• Ensuring that all applicable HB-44 requirements and test procedures are applied 

properly to commercial weighing and measuring devices is a shared responsibility of 

administrators and field officials that can only be achieved when they are committed to 

working together for the common good. As detailed in this article, there are plenty of 

resources available to help them achieve this end. For more information regarding how 

to obtain any of the resources mentioned in this article contact Rick Harshman at 301-

975-8107 or by email at richard.harshman@nist.gov.