Dear Jim, You are right -- this is quite interesting.
I have interspersed some further remarks. on 2005-02-19 04.15, Jim Elwell at [EMAIL PROTECTED] wrote: > We recently received a batch of custom cable (7,500 meters of it!) that has > too hard and stiff a jacket for us to use. We had failed to specify the jacket > durometer, so the vendor used whatever they had. Would it not be better to say: 'We had failed to specify the jacket hardness (instead of durometer), so the vendor used whatever they had'. I have found that it's generally better to use a quantity name to describe a quantity rather than the name of the instrument that measures it (in this case durometer) or the name of the unit (as some folk do with expressions like 'the amperage was 3 amps') > We then got a sample of a much less stiff cable, and this vendor specified > "Shore A 68 Durometer". I got doing some research on this and it's pretty > interesting: > > http://www.npl.co.uk/force/guidance/hardness/rubber.html > > Essentially you have an important material property that is so far from any > fundamental physical property such as mass or length that it is specified > purely empirically -- put a special indenting tool on the material and see how > far it dents. > > Nonetheless, the web site above does spec everything in metric units. I noticed that they used a comma as the decimal marker where it is more usual in English speaking countries to use a dot on the line as a decimal marker. This page, and no doubt many surrounding pages from the National Physical Laboratory (NPL) looks unnecessarily complex because of their poor choice of SI prefixes. Had they chosen to use micrometres instead of millimetres and millinewtons instead of newtons this page would be almost free of decimal markers and therefore much simpler to read. I suppose that it is possible, through wise choices of SI prefixes, to rid your workplace of fractions entirely. This applies to both vulgar fractions (1/2, 1/3, 1/4 etc) as well as decimal fractions (0.1, 0.12, 0.123 etc.) The Australian building industry is an almost fraction free zone because of their use of millimetres. > More interesting info at http://www.machinist-materials.com/hardness.htm, > comparing the different hardness scales. Even this US site is pretty much all > metric. Yes, but it's a strange sort of metric. The good folk who made this useful comparison have yet to discover Isaac Newton's insight that mass and force (weight) are two different things. This is, no doubt, why they chose to use kilograms and grams for their TEST FORCE RANGE rather than the correct SI unit of force, the newton. This area looks to be screaming out for the standards writers to come to their rescue by writing a uniform standard using an SI unit such as a pascal (newton per square metre) in one or several of its many forms from millipascal to megapascal. > Jim > > P.S. anyone need 7.5 km of cheap ethernet-ready cable? > Thanks for your kind and generous offer. Cheers, Pat Naughtin Geelong, Australia 61 3 5241 2008 [EMAIL PROTECTED] http://www.metricationmatters.com This email and its attachments are for the sole use of the addressee and may contain information that is confidential and/or legally privileged. This email and its attachments are subject to copyright and should not be partly or wholly reproduced without the consent of the copyright owner. Any unauthorised use of disclosure of this email or its attachments is prohibited. If you receive this email in error, please immediately delete it from your system and notify the sender by return email.
