TRAINING FOR THE WEIGHTS AND MEASURES OFFICIAL - PowerPoint PPT Presentation

COURSE CURRICULUM

COURSE CURRICULUM

Module Nine“Weighing Devices”

Ninth in a series of 14

General Overview

This module will:

Familiarize you with weighing devices

Introduce various terms and definitions

Discuss enforcement tools used by the field inspector

Prepare you for “hands on” field training

Understand the difference between commercial and non-commercial use

Understand the importance of type approval

Be able to describe the basic construction and use various weighing devices

Be familiar with the reference tools used in inspection and testing weighing devices

In every commercial transaction involving the weighing of a commodity over a scale, accurate weights and proper weighing practices protect both the buyer and seller

• Buyer and seller have a right to equity

• The seller has a right to fair value

• The buyer can compare values

Commercial

Determination of Weight

For the purchase or sale, barter or trade of any commodity or thing

Of any commodity or thing upon which determination of a charge for service is based

Includes devices such as parcel scales, shipping scales, and scales used in the payment of agricultural workers

Normally occurs in the presence of the customer

If not, a weighmaster certificate is required

Non-Commercial

Weighing performed within a business as part of the manufacturing process

Pre-packaging scales used for filling packages to a pre-determined weight

The determination of charges for the transmission of letters or parcels of less than 150 pounds, except when that determination is made in the presence of the customer charged for the service

Role of Weights and Measures

Responsibility of the Weights and Measures Official

Inspect, test and seal commercial scales that are correct

Ensure that weighing practices protect the interests of all parties

Remove scales from commercial use that are found to be incorrect

• Business and Professions Code of California
• § 12027 & 12107The Secretary of Food and Agriculture may:
• Make laws and regulations
• Establish tolerances, specifications and other technical requirements for commercial weighing and measuring

NIST Handbook 44

• Adopted by reference, with exceptions

Business and Professions Code

DMS – Field Reference Manual

Device Enforcement Program Manual

Business and Professions Code:

Division 5, Chapters 1-17, pertaining to Weights and Measures

These are the laws adopted by the State Legislature requiring you, or prohibiting you from doing something

More information about Laws and Regulations is discussed in Training Module 2

References the California Code of Regulations(Title 4, Division 9)

NIST Handbook 44 adopted by reference, with exceptions

CCR 4000 sections same as HB 44

CCR 4001 sections are not adopted from HB 44

CCR 4002 requirements are different than, or in addition to requirements in HB 44

• The specifications, tolerances, and other technical requirements established by the California Code of Regulations apply to:
• Commercial weighing devices
• Any accessory attached to or used in connection with a commercial weighing device that affects the accuracy of the device
• Weighing devices used for law enforcement purposes

G.

This prefix indicates the requirement is part of the general code

Application. Type of device or subject the section applies or does not apply to

A.

Specifications. Relate to design of equipment. Mostly applies to equipment manufacturers

S.

N.

Notes. Applies to the official testing of the device

Organized into different codes by type of device or subject

Tolerance. Performance requirements that fix the limitsof allowable error from true value

T.

Tolerance for scales marked with an accuracy class (Jan. 1, 1986)

T.N.

User Requirement. Directed to the owner of operator ofthe device. Applies to the selection, installation, use, and maintenance of the device

UR.

Definitions of Terms. In appendix D, provides a definitionof terms having special meaning

D.

Includes basic considerations associated with theenforcement of device code regulations:

Theory of Tolerances

Inspection vs. Testing

Methods of Sealing

Checklist to determine jurisdiction for weighing andmeasuring devices interfaced to computer systems

Directory of DMS Notices, DMS Policy Letters andEPO References

It also incorporates the ‘Examination Procedures Outline for Commercial Weighing and Measuring Devices’

Guide for determining if devices are correct and suitable for commercial service

Outline for a minimum examination preceding official action

References sections of B&P and CCR

Checklists for:

Newly Installed Weighing Devices

Indicators – Automatic & Non-Automatic

Shift Test & Substitution/Strain Load Tests

Electromagnetic Interference Test

Weight Truck Calibration Guidelines

Measuring Devices

Weighing Devices

Customer Operated Devices

Words of Caution to Weights and Measures Officials

• Program manuals and Examination Procedures Outline are onlyguidelines to assist you with your job

• They are notthe law
• They cannot be referenced as violations when issuing a Notice of Violation, or writing a citation, criminal or civil case
• You must reference the correct Business and Professions Code or California Code of Regulations

Load-Receiving Element

Weighing Element

Indicating Element

All scales have the same basic components:

The load rests upon a:

Platform or deck of wood, steel or concrete

Platter or pan, conveyor belt, hopper, tank or monorail

Supported by a suspension system that transmits the load to the indicating element

• Transmit the force of the load from the load receiving element to the weight indicating element
• Lever Systems - Mechanical scale
• Load-cell Systems - Electronic scale
• Electro-mechanical - Both mechanical and electronic

Transmit the force of the load from the load receiving element to the weight indicating element

Lever Systems - Mechanical Scale

Load-cell Systems - Electronic Scale

Electro-mechanical/Levertronic

- Both mechanical and electronic

Weighbeams

Dials

Electronic Indicator

Non-Automatic Indicators

Scale operator must perform action to obtain reading

Typical Weighbeam Assembly

Weighbeams with a sliding poise can balance a considerable range of load

Read when the weighbeam tip rests in the center of the trig loop or when tip oscillates equidistant from the center

Counterpoise Weights

Capable of balancing large loads depending upon scale ratio

Requires computation to obtain total weight

Counterpoise weight with scale ratio (1 lb. weight will balance a 100 lb.load on the scale deck)

Over and Under Indicator

Graduated Balance Indicator

Weighbeams with balance indicators

Analog

May indicate throughout the whole range of the scale

Chart capacity only or … test at the quarter positions for linearity

Tare Bar - For balancing off the weight of an empty container

Capacity Bar - To supplement the capacity of the reading face

May be equipped with a:

Applications

Electro-mechanical Scales

Mechanical scales converted to electronic indicator

Electronic dials

Levertronic Scales

Both mechanical and electronic indicators

Tested as two separate scales

Full electronic Scales

lbkg

ZERO

PRINT

TEST

TARE

CLEAR

Push-Button Controls On An Electronic Indicating Scale

Common features:

Tare mechanism (must be indicated)

Push-button tare Keyboard tare Dial tare mechanism

Gross/net weight

Push-button print

On-Off switch

Zero-setting mechanisms

Semi-auto and auto-zero

Center of zero indication

Unit selection (must be indicated)

Computing Scales

Indicate money values for an amount of product weighed at predetermined unit prices

Point of Sale Systems

Consists of a scale and indicator interfaced to an electronic cash register (ECR), many times with a scanner. This system may utilize price look-up (PLU) codes which may have tares automatically entered for a product

Weighing devices are divided into accuracy classes according to the number of scale divisions (n) and the value of the scale division (d).There are five classes of scale categories:

• The majority of commercial scales fall into class III or III L
• Scales manufactured after Jan. 1, 1986 are required to be marked with these class designations
• Older scales without these designations are referred to as ‘unmarked’ scales. These scales are placed into classes based on their use
• Application of scale tolerance depends upon the class of scale being tested

Tolerances are accuracy criteriaused by weights and measures officials

Scale tolerance values are based on scale divisions or the number of ‘d’

• Errorless value or performance is unattainable
• Tolerances are established to fix the range of inaccuracy acceptable for commercial use
• “Tolerance values are so fixed that the permissible errors are sufficiently small that there is no serious injury to either the buyer or the seller of commodities, yet not so small as to make manufacturing or maintenance costs of equipment disproportionately high.”

• CCR - Scales
• Sets the tolerance limit for inaccuracy allowed for a particular device
• Acceptance Tolerance is generally one-half of maintenance tolerance and is applied to scales that are new or undergoing type approval
• Maintenance Tolerance permits an additional amount of deterioration before the scale is placed ‘out of service’. Applies to scales already in commercial use

Type Approval:

Check compliance with certificate of approval or conformanceInclude software verification where applicable

Suitability:

Consider appropriate use weighing produce with a postal weight classifier

Minimum load – not less than 20 d

Marking Requirements:

Required information aids in determining suitability and approval

Common to all devices

Manufacturer name, initials or trademark

Model designation

Nonrepetitive serial number

Additional information that may be required on scale systems and components depending upon manufacture date:

NTEP Certificate ofConformance Number

Maximum Scale Divisions

Concentrated Load Capacity

Accuracy Class

Nominal Capacity

Minimum Dead Load

Scale Division

Maximum Capacity

emin and vmin

Section Capacity

The primary purpose of a scale examination is toensurethat the device isaccurateandcorrect

A device can be accurate but not correct

• To be accurate a scale must meet, within applicable tolerances, specific performance requirements determined during testing
• To be correct a scale must be accurate and meet all applicable specification requirements (design, type approval, selection, installation, use, and maintenance)

• Inspection Procedures include verification of ‘Method of Operation’
• Used according to manufacturer’s instructions
• No facilitation of fraud
• Compliance with user requirements

• Testing is done to determine compliance with performance requirements
• Testing will vary according to the device being tested
• Testing procedures are contained in the EPO found in the Device Enforcement Program Manual
• It is recommended that you train with qualified county or state officials before proceeding with field testing
• There are numerous safety issues to consider before testing a device

When a device is found to be ‘correct’, it must be sealed before commercial use

In addition to the familiar approval seal, most devices have provisions for security sealing mechanisms used by service agents to make adjustments and calibrations

There are primarily three ways to secure the calibration and parameter mechanisms

Although none will prevent access, they provide evidence of tampering

Security Sealing

The traditional method using a lead and wire seal

Another method is with tamper-resistant or pressure sensitive seals. These will tear or transfer markings if an attempt is made to remove the seal

If either of these seals are not intact,the integrity of device is compromised

It is illegal to use an unsealed devicein commerce

Many electronic indicators are capable of calibration and parameter changes through the keyboard

These are sealed with either a physical seal to a calibration switch or with an electronic ‘audit trail’ that is password secured

The ‘audit trail’ has two counters that monitor access to the configuration parameters and the calibration parameters

These counters increment each time a parameter is accessed

When devices are capable of parameter changes through remote access, more sophisticated tracking may be necessary

An event logger may be required depending upon remote configuration capabilities or category of device

Categories of Device and Methods of Sealing are contained in Table S.1.11. of the CCR 2.20 Scales

The device type approval or certificate of conformance will indicate how the device is to be sealed

When a device is sealed with audit trails, those numbers must be recorded on the certificate of inspection. Recording those numbers is how you, as an inspector, seal that device

The device type approval or certificate of conformance will indicate how to access the audit trail numbers

During routine inspection or complaint investigations, the audit trail numbers are accessed and compared to numbers from the previous inspection or service agency ‘placed in service’ reports

Unauthorized or unreported access should be researched and action taken as in cases where physical security seals are compromised

For information on responsibilities of Service Agencies and Agents refer to Module 14

A sealer may permit the use of an unsealed device pending repairs if the device is in error only to the disadvantage of the user and the user is always the seller. Such an unsealed device shall be repaired within 30 days. Check with your supervisor so you may follow your county procedures.

B&P Code

§ 12501.3

This is not permitted for a device used by a weighmaster

Devices that do not meet the tolerances and specifications are removed from service with an ‘Out of Order’ tag.

Some counties allow continued use if the device is against the seller

When a device is not approved for commercial use, do not use an‘Out of Order’tag

Affix an ‘Unapproved Device’ tag in a conspicuous place

Issue a Notice of Violation for a device found out of compliance

• Commercial vs Non-Commercial
• Responsibilities of Weights and Measures
• Reference Tools: when, where and why they are applied
• Types of Devices and Components
• Inspection vs. Testing
• Field Examination
• Evaluation and Disposition

This training module has provided you with a better understanding of weighing devices and the resources available to aid you in their inspection.

TRAINING FOR THEWEIGHTS AND MEASURES OFFICIAL

This Concludes Module 9“Weighing Devices”