How are speedometers designed to accommodate the change from mph to km/h? In this article I will examine a variety of techniques and at the end of the article I will propose a 21st Century solution.
Continue reading “Speedometers and Metrication”Category: Technical
The case for Mondopoint shoe sizes
Mondopoint is a footwear sizing system based on the foot length and linear width of the foot and is measured in millimetres. It is part of ISO standard 9407:2019, which describes the specification for Mondopoint system of sizing and marking. 1 It has the potential to replace various mutually incompatible shoe sizing systems used in different countries. Most of these systems use arbitrary numbers that do not relate to anything obvious. Even worse, different sizing systems are often used for men, women and children.
Continue reading “The case for Mondopoint shoe sizes”Official thinking on dual unit road signs in the 1960’s
HM Government looked at the case for and against the use of dual unit road signs as an intermediate step in the metrication of road signs in the second half of the 1960’s. Three different methods for dual unit sign conversion were evaluated and some technical issues related to dual unit signs were discussed. The findings and illustrations from the National Archive papers are presented here.
Continue reading “Official thinking on dual unit road signs in the 1960’s”Was the 1824 Weights and Measures Act a help or a hindrance for metrication?
The 1824 Weights and Measures Act introduced imperial standards based on physical objects with certain characteristics, such as the Imperial Standard Yard, and a single set of volume measures based on the new Imperial Gallon for dry and liquid measures to replace several that were in existence. To mark 200 years since the passing of the 1824 Weights and Measures Act, I look at the main features of the Act and ask whether it was a help or a hindrance on the path to metrication in the UK.
Continue reading “Was the 1824 Weights and Measures Act a help or a hindrance for metrication?”Is that really one kilogram?
When a retailer weighs out his product in front of the customer, can the customer trust the scales? It is usually up to local government to certify the accuracy of such scales, though in recent years, certification of measuring devices within much of the world has been privatised with various countries’ national laboratories overseeing the certification process.
Continue reading “Is that really one kilogram?”Which non-SI units are accepted for use with the SI?
SPOILER ALERT:
The official UK and USA metrology websites are INACCURATE
Since the inception of the International System of Units (SI) in 1960, it has always been recognised that some non-SI units, such as the litre, minute and hour, are “widely used and are expected to continue to be used for many years”.
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Early Metrication on Southern African Railways
During the last decade of the nineteenth century, events in Southern Africa were dominated by the gold rush as adventurers scrambled to exploit the newly discovered in the Johannesburg area. This and the egos of and animosity between the financier and Cape Colony prime minister Cecil John Rhodes and the aging and dour president of the Transvaal Republic Paul Kruger resulted in the Anglo-Boer War of 1899-1902.
Continue reading “Early Metrication on Southern African Railways”Driverless Cars
The on-going development of driverless cars is seldom out of the headlines. There are questions about the reliability of the software which will drive the cars and who will be liable should there be an accident.
Continue reading “Driverless Cars”International Vocabulary of Metrology
International Vocabulary of Metrology (VIM) is a “System of Units”, not a “System of Measurement”. The VIM explains the terminology used in publications related to measurement, including the official SI brochure.
Continue reading “International Vocabulary of Metrology”International Organisation for Legal Metrology
The International Organisation for Legal Metrology (OIML from the French “Organisation Internationale de Métrologie Légale”) is housed in a non-descript office in the Rue Turgot in the 9th arrondissement of Paris and is about 700 metres the from the Gare du Nord. Like the BIPM, the OIML is an inter-governmental organisation which gives its staff quasi-diplomatic status, though, like the BIPM, French nationals pay French income tax. The OIML works closely with BIPM, the International Standards Organization (ISO) and other international bodies in coordinating metrology around the globe, with each organisation having its own specific role.
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Metric Views 