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TRAINING FOR THE WEIGHTS AND MEASURES OFFICIAL. COURSE CURRICULUM. TRAINING FOR THE WEIGHTS AND MEASURES OFFICIAL. COURSE CURRICULUM. TRAINING FOR THE WEIGHTS AND MEASURES OFFICIAL. Module Nine “Weighing Devices”. Ninth in a series of 14. General Overview. This module will:
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TRAINING FOR THEWEIGHTS AND MEASURES OFFICIAL COURSE CURRICULUM
TRAINING FOR THEWEIGHTS AND MEASURES OFFICIAL COURSE CURRICULUM
TRAINING FOR THEWEIGHTS AND MEASURES OFFICIAL 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
Module Objectives 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
General Considerations 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 or Non-Commercial 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
Commercial or Non-Commercial 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
Authority • 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
Reference Tools Business and Professions Code DMS – Field Reference Manual Device Enforcement Program Manual
Business and Professions Code 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
Field Reference Manual 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
California Code of Regulations • 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 CCR Paragraph Designations 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. CCR Paragraph Designations
Device Enforcement Program Manual 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
Device Enforcement Program Manual 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
Examination Procedures Outline 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 Scale Components All scales have the same basic components:
Load-Receiving Elements 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
Weighing Elements • 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 Weighing Elements
Indicating Elements Weighbeams Dials Electronic Indicator
Non-Automatic Indicators Scale operator must perform action to obtain reading Typical Weighbeam Assembly Weighbeams
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 Weighbeams
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) Weighbeams
Over and Under Indicator Graduated Balance Indicator Weighbeams 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 Dial Indicators
Tare Bar - For balancing off the weight of an empty container Capacity Bar - To supplement the capacity of the reading face Dial Indicators May be equipped with a:
Electronic Indicators 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 Electronic Indicators 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)
Electronic Indicators 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
Accuracy Classes 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:
Accuracy Classes • 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 Tolerances are accuracy criteriaused by weights and measures officials Scale tolerance values are based on scale divisions or the number of ‘d’
Theory of Tolerances • 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.”
Tolerances • 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
Pre-Test Determinations 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
Marking Requirements Common to all devices Manufacturer name, initials or trademark Model designation Nonrepetitive serial number
Marking Requirements 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
Device Inspection The primary purpose of a scale examination is toensurethat the device isaccurateandcorrect A device can be accurate but not correct
Device Inspection • 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 • Inspection Procedures include verification of ‘Method of Operation’ • Used according to manufacturer’s instructions • No facilitation of fraud • Compliance with user requirements
Testing • 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
Sealing 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 Physical 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
Electronic Sealing 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