November 2004 

Using NIST Handbook 44 

By Juana Williams 

NIST Handbook 44 is designed for use as a working tool by the weights and measures 

official, equipment manufacturer, installer, and service person; therefore, it should be 

readily available for all who use it. The official should be familiar with how to reference 

device requirements on a daily basis, but the user is not expected to commit Handbook 44 

to memory. Direct and frequent reference to the requirements is the only way to be sure 

that requirements are applied correctly. Handbook 44 includes test requirements meant 

to be applied under laboratory conditions that would not be practical in a field setting. 

Handbook 44 contains: 

Change Tables Lists of amendments and editorial changes made to that edition of 

Handbook 44 

Introduction Basic information about the development and use of Handbook 44 

Section 1 General Code requirements for all device types 

Sections 2 - 5 Code requirements for specific device types such as scales, liquefied 

petroleum gas liquid-measuring devices, taximeters, etc. 

Appendix A Fundamental considerations includes information that promotes 

uniform enforcement of Handbook 44 codes 

Appendix B Historical information on the origins and development of units and 

systems of measurement 

Appendix C General tables of units of measurement for easy reference 

Appendix D Definitions for special terms used in Handbook 44 

Each paragraph in Sections 1-5 has a letter-number designation for easy reference and 

finding groupings of related requirements. The paragraph-letter designations are as 

follows: 

G General Code - These paragraphs apply to all devices unless there is conflict 

between a particular General Code and specific device code requirement, in this 

case the specific device code supercedes the General Code requirement. 

A Application – These paragraphs pertain to the application of the requirements of a 

code to specific types of devices and those devices to which the code does not 

apply. 

S Specification - These paragraphs relate to the design of equipment. These 

paragraphs contain information that is directed particularly to the manufacturers 

of devices. 

N Note - apply to the official testing of devices. 
T Tolerance - indicate performance requirements. These paragraphs fix the limit of 

allowable error or departure from true performance or value. 

UR User Requirement - are directed particularly to the device owner or operator and 

apply to the selection, installation, use, and maintenance of devices. 

Requirements are classified with a status of either “retroactive” or “nonretroactive.” 

Retroactive requirements are enforceable with respect to all equipment. Nonretroactive 

requirements are those that are only enforceable on equipment that is manufactured or 

placed in commercial service after a specified effective date. Typically, a requirement is 

designated as nonretroactive to allow time for manufacturers to make changes to their 

production processes and to avoid creating unnecessary hardship to the device owner. 

In order to effectively enforce the requirements in NIST Handbook 44, field officials 

should be familiar with all paragraphs in Handbook 44, including those directed primarily 

to the manufacturer or device owner or user. Because Handbook 44 is continually 

updated to address the latest advances in technology and trends in marketplace practice, 

the inspector must routinely track changes to Handbook 44 requirements to be sure he or 

she is applying the Handbook correctly.