Services		CFTM		Approvals		Electricity		Volume
Sector Review		Authorized Service  Providers		Consumer Page		Natural Gas		Mass

M-17 Use of Aluminum-capped Mass Standards

PDF Format | Table of Contents

Date: 1995-03-15
Bulletin: M-17-E
Category: Mass

1.    The purpose of this bulletin is to clarify the use of aluminum-capped weights as local standards for inspecting devices. These weights are becoming increasingly common and are accepted in other metrological jurisdictions. They may be used as local standards if the following conditions are met:

1.1    The weight shall have a simple geometrical shape, with an open ended adjusting cavity drilled into its axis. The entrance to the cavity shall be located on the top flat surface of the weight and shall have a diameter larger than the cavity itself. The design of the cavity shall allow for the easy removal of adjusting material.

1.2    The weight shall have a nominal value no less than 100 grams (0.2 pound or 4 ounces) and no greater than 10 kilograms (20 pounds). The nominal value shall be marked with the correct symbol for the unit of measure. The weight may also be marked with an OIML accuracy class.

1.3    The weight shall be corrosion resistant and practically non-magnetic. Its surface shall have round edges and a smooth, non-porous appearance with no pronounced hollows.

1.4    The adjusting cavity shall have a recessed opening, the depth of which is sufficient to prevent the backup disk and the sealing cap from protruding above the surface of the weight.

1.5    The backup disc shall be constructed of aluminum or similar metallic material to prevent the sealing cap from being driven into the cavity when the weight is stamped. The backup disc may be solid or may have a hole in the centre no larger than ¼ inch in diameter. The cavity is sealed with an aluminum cap, driven into the recessed opening by force.

2.    These weights may be designated as local standards for inspecting devices used in trade. Clients requesting Measurement Canada certification of these weights shall supply the backup discs and aluminum caps for their weights. Weights marked with an OIML accuracy class will not be adjusted to a higher accuracy class.

3.    For additional information, please contact:

Jeff Watters
Program Officer, Mass and Commodity Measurement
Program Development Directorate
Measurement Canada