Language selection


Field Inspection Manual — Non-Automatic Weighing Devices

Part 2, Section 9: IPO-9: Overhead Track Scales


Electronic or mechanical overhead monorail scale; or combination of monorail/platform scale.


Inspector's weight kit, local standards of sufficient number and capacity, weight suspension equipment.


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

Adequate facilities to apply test standards or test product are provided

Device is adequately supported; holding rods and brackets affixed solidly

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

Load receiving element can be observed from indicator's reading position

Clearance around overhead track

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 (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


Scale marks, pointers and poise are in good condition

Defining words and symbols are readable

Zero setting material is enclosed and secured

Balancing ball is in good condition and secured in place

Visual Examination — Recording Element (Printer) (STP-6)

Device prints the required values

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

AZTM 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)

Multi-deck Weighing Systems (Combination monorail/platform scale) (STP-26)

Selection of the weighing element (Interlock)

Identification of the load receiving element in use (Electronic)

Identification of the load receiving element on the ticket

In the case of a combination monorail/platform scale, the monorail scale and the platform scale are tested separately. See IPO for platform scales.


Original document


Footnote 1

Test performed at the initial inspection only.

Return to footnote 1 referrer

Date modified: