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Field Inspection Manual — Non-Automatic Weighing Devices

Part 2, Section 2: IPO-2: Point of Sale (POS) Weighing Systems


Electronic POS systems used in conjunction with cash registers or computers. A POS system is defined as a weighing element or non-computing scale interfaced with an electronic cash register (ECR) or computer and intended for use in direct sales of individually measured commodities to a consumer. The ECR or computer obtains the gross weight provided by the scale, may calculate a net weight based upon appropriate tare values, and calculates a total price proportional to the weight of commodity being measured. The price per unit for the commodity may be manually entered or may be derived from a Price Lookup Code (PLU). Stand alone price computing scales, weight classifiers and other scales used in weight classification applications are not to be considered POS systems.


Inspector's weight kit.


Device is approved for trade use (NoA, Act Section 8)

Device is suitable for the actual use (STP-1)

Device has been initially inspected (if applicable) and bears the initial verification marks (R.29)

Device is sealed (NoA, STP-4)

Visual Examination — Installation and Location (STP-7)

Device is installed in accordance with restrictions and conditions listed in the notice of approval and in accordance with manufacturer's instructions

Device is adequately supported

Device indicating and load receiving elements are positioned for customer's view (if applicable)

Clearance around load receptor

Device is properly levelled and secured as appropriate

Device is adequately protected

Visual Examination — Marking (STP-3)

Device is marked with the required information

Marking is located as required

Marking is permanent (if applicable)

Marking plate is permanently attached to the device

Visual Examination — Indicating element (Electronic) (STP-5)

Display Test (Segment)

Indicated and recorded values are adequately defined

Defining words and symbols for annunciators (Tare Entered, Gross and Net Weight, Center-of-Zero) are readable

Visual Examination (Recording element) (STP-6)

Recording element (Cash Register Tape) in compliance

Cash register tape contain all required information

Printed values are adequately defined

Device Configuration (Electronic)

Device configured as prescribed by the NOA (STP-2)

Zero Setting Mechanism Range ( 4% of Max or more) (STP-8)

Initial Zero Setting Mechanism Range (20% of Max or more) Footnote 1

AZSM Maximum Range (0.6 e)

Manual Entries of Gross Weights (STP-9) Footnote 1

Sleep Mode Test (STP-10) Footnote 1

Tare (Platter, Keyboard, and Pre-programmed Tare Entry) (STP-11)

Free Floating Weight Signal (STP-12)


Load Discrimination Test (Near Zero) (STP-14)

Increasing Test (STP-13)

Eccentricity Test (STP-15)

Load Discrimination (Max) (STP-14)

Agreement of Registration (STP-17)

Display Blanking Tests (Zero, Tare) (STP-18)

Decreasing and Return-to-Zero Test (STP-13)

Repeatability Test (STP-16)

Motion Detection Test (STP-19)

Accuracy of Price Computation (STP-20)

Mathematical Concordance of Tare, Net and Gross Weight (STP-21)

Disturbance Test (Electromagnetic Interference and Radio Frequency Interference, Vibrations) (STP-23)


Rev 1.

  • added POS definition.


Footnote 1

Tests performed at the initial inspection only.

Return to first footnote 1 referrer

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