Date: 2002-04-26
Bulletin: V-23-E
Category: Volume

1. Purpose

The purpose of this bulletin is to clarify when acceptance limits of error (LOE) apply and when in-service limits of error apply.

Acceptance LOE apply to all initial inspections of measuring devices in a factory setting and to devices being evaluated for approval purposes, including those done in the field.

In-service LOE apply to all inspections conducted in the field other than those for approval purposes.

2. Background

Per section 2 of the Weights and Measures Regulations, the use of acceptance limits of error is based on the conditions surrounding the inspection including: the initial inspection of the device; approval evaluations; repair to the measuring elements following failure of the device to measure within the applicable LOE; and within 30 days after the time of the last two conditions. In addition, sections in the regulations specific to limits of error for devices state that the use of acceptance limits of error apply to tests made under “controlled conditions”. There is not unanimous agreement that the controlled conditions as outlined in Bulletin V-3 can be easily met or measured in the field without measurement instrumentation (thermometers, pressure gauges, etc.); nor is there any current data to support the widening or narrowing of the scope of these conditions.

At the time of writing this bulletin, Measurement Canada is reviewing the current LOE tables applicable to measuring devices against other international standards with the intent of clarifying and simplifying the tables in the future. It has been noted that the Canadian acceptance LOE are possibly the tightest in the world which must be rationalized, given the extreme environment devices are used in this country. It is anticipated that the Canadian limits of errors will at some point have to be aligned with other legal metrology organizations around the globe.

To summarize, due to the uncertainty as to whether controlled conditions can be achieved in the field, in-service limits of error should be applied to all inspections conducted in the field, except for evaluations conducted for approval purposes. Factory inspections and evaluations for approval purposes should apply acceptance limits of error.

3. For additional information regarding this bulletin, please contact the undersigned.

Dennis Beattie, CET
at beattie.dennis@ic.gc.ca
Senior Program Officer
Volumetric Measurement

2002-04-26


		Created: 2003-07-08 Updated: 2005-01-25	Top of Page	Important Notices