The first (1999) edition of this standard is intended to meet an industry and consumer need for some degree of standardization to assist users in the selection and installation of load cells.  To this end this standard provides for manufacturers:

A list of specifications to be made available to the user along with the terminology and units of measure to be used. 

The terminology to be used when referring to the conductors of the load cell cable, along with a color code to be used for new load cell models.

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This user guideline was produced to supplement the SMA Standard for Load Cell Specifications.
It is the purpose of this guideline to promote greater understanding between manufacturers and users of load cells by establishing uniform terminology, method of specification, and test procedures for load cells.

A primary objective of the standard is the establishment of simple and readily understandable definitions. As much as possible, terminology has been defined in a manner such that the term can be expressed quantitatively and in a straightforward manner.

It is also an objective of the standard to establish a common term or title for each performance characteristic relating to load measuring devices. Where several terms pertaining to the same definition are in common usage, preference will be indicated by listing the definitions under the preferred term.

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The purpose of this standard is to specify a range of environmental conditions that would enable an end-user of a device covered by this SMA document to determine the suitability for their application. The standards allow a manufacturer to define a range of test criteria that would enable product testing to realistic application-environment conditions.

The Scale Manufacturers Association designed this standard to be self-administrating. It is
the responsibility of each manufacturer to validate his claim by evidence of testing and
positive testing results, that the model meets or exceeds the requirements mentioned in or
referenced in this document

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This standard contains the basic requirements for limited feature scale products to communicate weight and status information to a smart host device.  It was determined by the SMA Standards Committee, early on during the specification process, that all the requirements for all of the different types of scale products in the world could not be addressed by one all encompassing standard.  The SMA  Standards Committee decided to address only the requirements for a limited feature weighing scale device at this time.  Even after recognizing that we could only take this first step toward communication standardization, we found it necessary to address two levels of scale communication in this standard.  Hence, we have devised SMA level ‘#1’ for the most limited feature of scale weighing devices and SMA level ‘#2’ for the more powerful, fully featured scale device.  Because of the varied applicational needs for scale communication, this Standards Committee has decided to continue to meet in the future and tackle other serial communications protocols, but only after the base line is set with SMA levels #1 and  #2.

A limited feature scale is defined as a weighing device with only limited microprocessor capabilities. There are a number of microprocessors that fall into this category due to either processing power or because of limited memory space availability.  This SMA Standards Committee did not wish to preclude such limited feature scale devices from being SMA compliant. More robust scales may wish to implement this standard in its entirety. It is up to the manufacturer to design in which level of this standard their scale will comply with based on the requirements of the device placed in the market.  All devices must comply with the requirements of SMA level #1, at a minimum, in order to claim SMA Serial Communication compliance. Version M1 corrects a typo in one of the command sets..

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SMA Standard for Vehicle Scale Characterization
(SMA VCS 11-02)

The purpose of the standard is to provide criteria for characterizing the service life of a vehicle scale based on the concentrated load capacity (CLC) rating of the platform. Potential scale owners and operators desiring to select the proper vehicle scale for a given application can use this knowledge. The service life of a vehicle scale is dependent on the cumulative number of load cycles and the level of the load-induced stress developed during the load cycles. The number of loads is determined by the number of weighments multiplied by the total of the single axles and groups of axles per vehicle. To quantify the level of loadinduced stresses in the scale system, the CLC
rating is used as a baseline load for determining the expected service life of the
device.
The standard provides tables for service life recommendations for platform spans of less than and greater than fifteen feet. The tables are based on a design fatigue life of scale structural members developed from nationally accepted engineering standards and specifications e.g. the American Institute of Steel Construction (AISC) “Manual of Steel Construction” and the American Association of State Highway and Transportation Officials (AASHTO) “Standard Specification for Highway Bridges”. Manufacturers are cautioned to verify design compliance with the fatigue life criteria of these standards using full CLC load ratings.

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SMA Standard for a Software Sealing Method of Access
(SMA SSM 11-02)

At the 74th NCWM in 1989, the National Conference on Weights and Measures approved the general use of audit trails as an approved method for the sealing of electronic adjustable features on devices. Since then, many manufacturers have taken advantage of this sealing method. However, each device manufacturer has generally been free to implement the audit trail sealing alternative as it sees fit.

Because there were no standards specified as to how this information could be accessed by field inspectors, there has been a proliferation of methods to access the audit trail. This led to confusion and even apprehension among inspectors. The apprehension further led to policies in a few jurisdictions which have discouraged field staff from "fooling around" in an effort to retrieve the information in the audit trail software.

In an effort to demystify the use of audit trails, the Weights and Measure Division at NIST has prepared a training module addressing the general requirements for sealing using software techniques. This information was presented at NIST sponsored training seminars and a "light" version was presented to each of the regional Weights and Measures annual meetings in 2002. Industry joined NIST in this effort with Gasoline Pump and Scale Manufacturers presenting details of the features and characteristics of scale and pump audit trail implementation methods.

The SMA offers this standard that defines a uniform procedure used to access the parameter and calibration counters for Category 1 and 2 scale sealing methods and the event log used in the Category 3 scale sealing method. The specific requirements for the software sealing methods are contained in NIST Handbook44, section G-S.8 Provision for Adjusting Electronic Adjustable Components

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The first (1999) edition of this standard is intended to meet an industry and consumer need for criteria associated with the design and suitability of weighing devices (scales) used in applications where shock and overload conditions are expected.

Scales are subject to shock loading and overload during their normal use.  This document quantifies the abuse a scale that meets this standard can withstand. 

This knowledge can be used by potential scale owners and operators to properly size a scale for the applications they intend. .

The Standard can be applied to mechanical or electronic devices. 

The Standard applies to complete scales or scale platforms and does not include consideration of individual scale components such as load cells. (For Load Cell Selection, see the SMA Load Cell Specification).

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The first (1999) edition of this standard is intended to meet an industry and consumer need for a single starting location where they can clarify the issues associated with Electrical Disturbances that may influence a weighing device or which may be generated by a weighing device. 

These disturbances manifest themselves as Radio Frequency Interfence, Electromagnetic Discharge, Power Line Voltage Variations and Interruptions, Power Line Electrical Fast Transients, and Power Line Voltage Surges.

This document serves as the unified Scale Manufacturers Association guidance in two areas of concern:

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