In article ,
Matt writes:
(Andrew Gabriel) wrote:

In article ,
Matt writes:
To eliminate the possibility of confusion on the merits of the various
cleaners could you quote the minimum pressure achieved at the nozzle
and the corresponding air flow for:

That measure is rather meaningless. The measurement accepted by
the industry is "suction power" as defined in IEC Standard 60312.

Thanks for that but "suction power" (how the hell did that get adopted
as an IEC standard!) is *precisely* why I concentrated on what to my
mind really matters, - the air volume at the nozzle and the pressure,

That's what "suction power" is -- the vacuum pressure multiplied by
the air flow. Neither the vacuum nor the airflow are meaningful by
themselves -- a vacuum pump and a large desk fan would have better
individual ratings than a vacuum cleaner, but are useless at cleaning
floors.

these taken both in the as new state and in an aged state after
passing a certain volume of air laden with a specified mass of dust.

As I said before, unfortunately the standard fails to take into
account the rapid drop off of bagged cleaners.

Combine this with the maximum size of particulate at the air exit and
the mass of dust retained by the machine and you don't need anything
else to know what's better. All the parameters are measurable and
you'd only need some dust and carpet - to IEC/ISO standard of course
:-)

Well, there's also a "pick-up performance" measurement, which includes
a measurement of the effectiveness of the pick-up head and brush bar
if relevant.

--
Andrew Gabriel