Clarifying important metrology legislation

Edited by the Manufacturingtalk editorial team Oct 10, 2005

Over the past decade the weighing instrument market has evolved into a convoluted global business and has lead to some ambiguities over the issue of self verification.

Over the past decade the weighing instrument market has evolved into a convoluted global business and as a result, equipment making up even simple systems can come from different manufacturers.

Unfortunately this has lead to some ambiguities over the important issue of self verification.

The UK Weighing Federation is currently working closely with its members and bodies such as the National Weights and Measures Laboratory (NWML) and the European Committee of Weighing Instrument Manufacturers (CECIP) to clarify the situation.

* Background - European Directives are, in principle, useful platforms for promoting equal trade throughout the European Union by harmonising technical and legal requirements for products and services.

However they only give the basic framework for any legislation, requiring individual member states to interpret and consolidate the requirements in order to bring the directives into national law through acts of parliament.

Unfortunately this process can lead to ambiguities and misunderstandings.

EC directive 90/384, known as the non-automatic weighing instruments or NAWI directive, has brought important (and mostly positive) changes to legal for trade weighing across a wide spectrum of applications -from the retail scales in our supermarkets through floor scales to weighbridges and vessel weighing systems.

(A non-automatic weighing instrument (NAWI) is a weighing instrument that requires the intervention of an operator during the weighing process, for example to deposit on, or remove from the load receptor, the load to be measured and also to obtain the result.) NAWIs must satisfy the Essential Requirements of European Directive 90/384/EEC, as amended, and implemented into UK Law under the Non-automatic weighing Instruments Regulations 2000 (S.I.

2000 No.

3236).

Before a weighing instrument is placed on the market the design and operational aspects of the instrument undergo a formal and thorough testing by a Notified Body such as the National Weights and Measures Laboratory.

This prototype testing ensures the equipment meets the requirements of all the pertinent EU directives and relevant European Standards.

Provided the equipment meets all the criteria, a certificate is issued that in principle permits the equipment to be used for 'trade' transactions.

When the 'type' approved product is then placed on the market, each and every unit must undergo a verification process which confirms that the individual units meet the necessary accuracy and functional requirements as per the original prototype.

Under the NAWI Directive there are three options for 'verification'; the traditional verification by a Trading Standards Officer, unit verification where the verification and the Type Approval are combined*, and "self-verification" available for manufacturers with a quality system accredited by a Notified Body.

The correct name for this is 'EC Declaration of Type Conformity (guarantee of production quality') known in practice 'self-verification' or 'SV' as shorthand.

(This is available for unique installations and one-off systems.

Note that only one or two such verifications have been made since the Directive came into force in January 1993) The self verification Deregulation order is a fundamental change for a process, colloquially known as 'stamping', which has been typically carried out by Trading Standards Officers.

It is an amendment of the Weights and Measures Act 1985 ('The Act') and allows manufacturers, installers and repairers of weighing and measuring equipment to apply to the Secretary of State for approval to conduct their own verification under section 11 of the Act.

(Verification of weighing and measuring equipment, under section 11 of the Act, is the testing, passing as fit for use for trade within the UK, and stamping the passed equipment with the prescribed 'Crown Stamp').

This change has important commercial implications for companies, giving them and their customers much more flexibility.

However it is clear that this process must be closely monitored and policed by the authorities to minimise the possibilities of abuse and sharp practice.

The approved verifier must possess and operate an acceptable quality system, which fully encompasses the requirements of the legislation and the activities required to ensure that equipment is correctly verified, and that the necessary protection is maintained.

Approvals are granted for a specified time, are limited to specific equipment types and can be suspended or withdrawn if the approved verifier is found to be in breach of the conditions of their approval.

Once granted an approval the approved verifier's quality system is regularly audited to ensure continued compliance with the requirements of the Act.

* A UK DTI service - the NAWI Directive makes it clear that only the manufacturer can be accredited to self-verify.

The manufacturer can allow others to operate under his accreditation but they must follow his procedures, meet all the requirements of his accreditation, and work under his control as far as verification is concerned.

* Status Quo - over the years a number of UKWF Members have been accredited to carry out SV and have been allowed by the Notified Bodies to include in the scope of their accreditation weighing equipment manufactured by others.

The Notified Bodies have now realised that they went further than they should have in allowing this, and that they had no legal authority to do what they did.

As a result a number of UKWF members are now facing the prospect of having the scope of their accreditation reduced by the removal of any equipment that they are not the manufacturer of from the list of equipment that they are allowed to verify.

Who or what is the manufacturer has been the subject of a meeting between NWML, the Notified Bodies and the UKWF.

In general terms it has been agreed that the manufacturer is: * The organisation that undertakes the physical task of making or manufacturing an instrument, or: * The organisation that places an instrument on the market under its own name and takes legal responsibility for the item.

(In this case the organisation must have some level of control of the manufacturing process).

In order to help understand who is or is not a manufacturer, NWML have published a document with the title 'Guidance on the Designation of Manufacturers'.

This Guidance, together with a flow chart type decision tree is available on the UKWF web-site.

Typical examples may help understand the problems involved: * A distributor or dealer who buys in a complete self contained weighing machine (e g, a retail counter scale or a bench scale) from a supplier cannot be regarded as the manufacturer of that machine even if he marks it with his own brand name, because he has no level of control over the manufacturing process.

* A distributor buys in a self-contained weighing machine from a supplier and then modifies it in such a way that it is now a 'different' machine from the one he originally purchased, e g, he adds another load receptor or incorporates the machine into another system.

He can be regarded as the manufacturer if he marks the machine with his own name and issues an EC Declaration of Conformity for the 'new' machine or system.

* A dealer buys in an 'approved' indicator and load cells.

He then has a scale bottom work fabricated - it may be anything from a small platform to a weighbridge - and incorporates the load cells into it and connects it to the indicator.

The dealer is the manufacturer.

He must put his name on the machine and issue the EC Declaration of Conformity.

* The future - the UKWF recognises the implications of this grey area and has asked NWML to introduce amendments to the existing Regulations as a matter of urgency.

As their technical officer John Anthony explains: "We accept that NWML cannot do anything that is not permitted by the Directive and therefore cannot allow organisations that are not manufacturers to carry out self-verification on new machines".

"They can however, with an amendment to the Regulations, allow installers, dealers and repairers to carry out re-verification after the machines have been placed on the market and taken into service".

"NWML have indicated that they are sympathetic to this and will explore how quickly the amendments can be introduced".

" Secondly, through CECIP, the UKWF is contacting the European Commission to see if it is possible to get the Directive modified".

"CECIP raised the question about the definition of manufacturer at the last WELMEC (European co-operation in legal metrology) Working Group 2 meeting in June 2005".

"The Commission was represented at this meeting and they advised CECIP to write to the Commission Group that is currently looking at how Directives are implemented".

"The Commission representative also said that it was time that the NAWI Directive, now 15 years old, was reviewed and that this topic could form part of that review".

"However we are under no illusions that any such review is likely to be other than a long process".

" Both NWML and the Notified Bodies are aware of the problems that this change of interpretation will cause for UKWF Members".

"They are committed to adopting as wide a definition of 'Manufacturer' as they possibly can whilst staying within the limits set down in the Directive, and they will deal with all questions and queries as sympathetically as possible".

"The Federation will continue to work towards getting the facility to carry out verification available to as many Members as possible.".