Laboratory manual for the evaluation of non-automatic weighing devices

Part 2, section 7—Price computing feature

Table of contents


Reference

Sections 19, 30 to 35, 46 and 47of the Specifications Relating to Non Automatic Weighing Devices (1998)

7.0 Price computing feature – Generalities

Devices used for direct sale can incorporate some cash register functionality, such as computing a total price for goods based on its weight and a pre determined unit price. All three of these values must always be in mathematical agreement with one another. In addition various requirements are described below to ensure clarity for all parties and to prevent the facilitation of fraud.

7.1 Price computing devices must print the unit price when the total price is printed.

7.2 Displayed and recorded monetary values must comply with applicable requirements of section 3, Indication and Registration Representation, and of section 5, Values Defined in this Guide (e.g. Value of d, legible and readable, number of digits, decimal representation, defining words and symbols, etc.).

7.3 Devices intended for direct sale to the public

7.3.1 Devices must display the unit price when the total price is displayed.

7.3.2 When the device displays in kilograms, the unit price that can be entered and displayed is limited to price/100 g and price/kg.

7.3.3 When the device displays in Canadian units, the unit price that can be entered and displayed is limited to Price/lb.

7.3.4 When a device displays weight values on the basis of the gram or ounce, unit prices may also be entered and displayed on the same basis.

7.4 A weighing system must not display or record any values when the correct calculated values exceed the display or printing capability. (An entry of 8 digits made into a defined field length of 7 digits will give an error indication).

Clarification: If a unit price of $99.99/kg and a weight of 10.050 kg may be entered, then the total price display must have enough digits to display the extended price $1 004.90 (at least 6 digits).

7.5 The total price must be calculated accurately and rounded to the nearest one cent, by multiplication of weight and unit price, both as indicated by the device. Perform the test described in LG-7.02.

7.6 When the displayed weight is less than zero, the device must not be capable of displaying or printing a computed total price. Place a small load on the platter, tare it and remove it from the platter. A negative weight value should be displayed. Attempt to enter a unit price. Attempt to print this value.

7.7 When the scale indicates an overcapacity condition, the device must not be capable of displaying or printing a weight and/or computed total price.

7.8 The displayed weight and total price must be free floating, that is when the scale displays a unit price, a weight and a total price, if the weight or the unit price is changed the total price must change accordingly.

LG-7.01 Free floating signal

Purpose

To ensure that the displayed net weight and total price are free floating. That is when the scale displays a unit price, a weight and a total price, if the weight or the unit price is changed, the total price must change accordingly. All applicable tests are to be performed.

Procedure for price computing scales
Procedure for scales equipped with a tare display
Procedure for POS systems – Against a Price Lookup Code (PLU)
Procedure for POS systems – Against a manually scaled item
Interpretation of results

7.9 The device complies with the requirements if:

LG‑7.02 Agreement of registration of monetary values

Purpose

To determine if the scale computes accurately and rounds the values of total prices correctly.

Application

Applicable to any price computing scales and POS systems.

Test procedure
Interpretation of results

The monetary registration is correct if for a net weight (as outlined in the "Net Weight" column in the above table) and a unit price (as outlined in the "Unit Price" column in the above table) yields the corresponding indication (as outlined in the "Correct Indication" column in the above table).

Revision

Original document

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