Infrequent standards roundup

A4

One standard I should talk about because of my half-foolish challenge “How much do 8 trillion pages weigh?” is the A4 standard. Here are some things to say about it.

• Most people who have dealt with it know the simple fact that an A3 sheet can be cut along the smaller of the centre lines to form two A4 sheets. Similarly A3 can be derived from A2, A2 from A1, and A1 from A0. The beauty of the system lies in the constraining factors that the area of A0 is defined to be 1 m2, and the ratio of the side lengths is 1 to √2. It can thus be shown that this is the side length ratio of the smaller paper sizes, and of course that having a side length ratio and an area allows you to work out the lengths of the individual sides, given that the shape of the paper is an oblong rectangular lamina.
• There are actually B and C families of paper sizes too, with sizes geometrical derivable from the previous family or families. The most interesting feature of these, though, is perhaps that the C family is often used to define envelope sizes, with the property that an An page will fit into a Cn envelope.
• As you would hope, the standard defining all these is a formal, open, ISO standard, namely ISO 216 (and ISO 269 for the C family of envelopes). It was first enshrined as a standard in Germany, as DIN 476, but is now known there as DIN EN ISO 216.
• To deal with the issue of weight, there is a separate standard, ISO 536, which specifies a system of measuring paper weight in grams per square metre (g/m2), that is “grammage”. A typical A4 sheet has an area of 1/16 m2 since four area doublings (24=16) of an A4 sheet produce an A0 sheet of 1 m2 area. So with a grammage of 80 g/m2 for typical office paper, an A4 sheet would weigh 5 g (from the relation: grammage = mass / area → mass = area × grammage).
• That is enough information to answer the question. For 8 trillion pages, we would thus have 40 trillion grams of paper, which (under the short scale) means 40 000 thousand million grams (avoiding ambiguity by following the IEEE / ASTM SI-10 advice on the use of “billion”), which is 40 thousand million kilograms. We use kilograms since this is the SI unit (which I grudgingly accept over the more sensible-looking “gram” unit), but for a perhaps more imaginable figure, this is equivalent to 40 million metric tons. Another way of looking at this figure is that if you detonated that weight of TNT, it would release almost as much energy as the biggest nuclear bomb ever constructed.

Website usability

Since writing about usability, even mentioning that an ISO definition for it exists, I have found that ISO have tried to deal with the specific question of website usability.

• A committee is currently working on ISO / CD 9241-151, “Ergonomics of human-system interaction - Software ergonomics for World Wide Web user interfaces” but it is at stage 30 . 60 right now which means “Comments / voting summary circulated”.
• ISO 9241 is actually a large family of standards, some of which are already published, all connected by the fact they deal with usability in some form.
• In fact, ISO 9241-151 is apparently being written to replace ISO / CD 23973 entitled “Software ergonomics for World Wide Web user interfaces”. A working draft of this document from 2003 can be found here.

Surprising standards

In the background research to my previous post, I came across various standards of whose ISO approval I was either unsure or unaware. As I didn’t go into detail at the time, I will use this section to do so.

1. • AAC is specified in the standard ISO / IEC 13818-7.
   • Again, this is one part of a broader family of standards, ISO / IEC 13818, defining MPEG-2, with 13818-3 being the “MPEG-2 Part 3” or “MPEG-2 Audio” format.
   • AAC succeeds the popular MP3 or “MPEG-1 Audio Layer 3”, defined as part of the original MPEG-1 standard.
   • The MPEG-1 family of standards is given the official code ISO / IEC 11172.
   • Complicating the issue only slightly more is the fact that AAC is actually covered by another standard. Improvements were made outside of the MPEG-2 specification, and a newer version was specified under MPEG-4 Part 3, known formally as ISO / IEC 14496-3
   • Supporting AAC is made financially burdensome due to it being heavily patented.
2. • There is a standard called Manufacturing Message Specification (MMS) that describes a system that is chiefly designed for the automation of industrial processes.
   • MMS is formally recognised as ISO / IEC 9506.
   • You can read an introduction to it here and see an illustrated example of its application to space science here.
   • Being an open protocol, it can benefit (and be benefited by) open source software, such as the Free software Linux kernel.
   • A related standard from the electric power field is Utility Communications Architecture (UCATM) which is the brand name for IEC 61850.
   • Moreover, UCA Version 2,0 has been published as IEEE TR 1550.
3. • Most surprising of all is that there is an ISO standard for preparing the drink tea, ISO 3103 titled “Tea — Preparation of liquor for use in sensory tests”.
   • The standard was prepared by sub-committee 8, called “Tea”, of Technical Committee 34, called “Agricultural food products” of ISO.
   • It should also be mentioned that the standard is identical with a British standard, BS 6008 titled “Method for Preparation of a liquor of tea for use in sensory tests”.
   • Apart from explaining the procedure (for both with and without milk), the standard also specifies recommended pots and bowls to use.
   • Taking things to the complete extreme, there is also a pair of identical standards ISO 1839 “Tea — Sampling” and BS 5987 “Methods for sampling tea”, which describe the sampling process referenced by ISO 3103.
   • This standard is made all the more amusing by the fact that it comes after the invention of the phrase “ISO standard cup of tea” which was probably intended as a joke.
   • According to the Jargon File, an ISO standard cup of tea is “A cup of tea with milk and one teaspoon of sugar, where the milk is poured into the cup before the tea.”

Conclusion

Even in writing this post I have found more standards which would make this post even longer than it is, were I to write about them. I have even used some rare XHTML and CSS features to write this, which will have to be blogged some other time. Hopefully this shows that the world of standards is a vibrant and sometimes amusing place. Some standards are even useful on a day to day basis.

How long would it take me to blog all ISO standards? Well, if there were 27001 standards (which there aren’t), then as ISO have been going since 1947, they might be producing standards at a rate of more than 1 per day, so I would have to be blogging about 2 per day just to catch up within my lifetime.