EN45501 not sufficient for NAWI directive

During a recent meeting of the Measuring Instruments Committee it became clear that the previous announcement of the European Commission, to publish a note in November 2011, is delayed. The publication is now expected for December 2011. Also the transition period has been extended to 2 years. This means that existing approved instruments may be placed on the market until December 2013. In the same meeting, CEN reported that the amended standard EN45501 will be available by the end of 2012.

The note will state that for non-automatic weighing instruments the harmonised standard EN45501 (test B 3.4) does not give presumption of conformity for immunity to radiated electromagnetic fields as the state of the art is 10 V/m as stated in OIML R 76-1:2006.

Take expected changes into consideration

This still means that it is now urgent for manufacturers to (re-)design the non-automatic weighing instruments in order to withstand the 10 V/m tests. The European Commission will no longer accept instruments withstanding 3 V/m to be used in the European market.

We strongly recommend to take the expected change in requirements into consideration

If deemed necessary, NMi will perform both options (3 V/m and 10 V/m) until publication of the note, but we strongly recommend to take the expected change in requirements into consideration before deciding which levels to use. If an approval is issued with 3 V/m before the publication of the note, it would only be valid until December 2013.

Test B.3.4, “immunity to radiated electromagnetic fields”, in the current EN45501 describes a frequency range of 26 MHz to 1 GHz. Test B.3.5, “immunity to radiated electromagnetic fields”, describes a frequency range of 80 MHz to 2 GHz provided that test B.3.6, “immunity to conducted radio frequency fields” (frequency range 0,1 MHz–80 MHz), is also performed. Therefore, in addition to the increase in test severity, the tested frequency range is also expanded.

New EN45501

The work on amending standard EN45501 to include the new requirements of OIML R76-1 2006 started in 2007 and was supposed to be ready mid-2010. Unfortunately, the work was delayed and publication is now scheduled for end-2012. The new EN45501 will be almost identical to OIML R76-1 2006. Only references dealing with issues after placing on the market (for example, “subsequent metrological control”) will be removed from the standard. This approach is actually the same as the approach followed for the 1992 edition of EN45501, which was almost identical to OIML R76-1 1992.