| Scales |
It is evident, that the scales are apparatuses designate to weigh. The result of weighting is not quite comprehended so unambiguously. A lot of us have remembered yet that this what we got by weigh up it was the weight of subject, person and so on. Later [with the development of astronautics] the differentiation was necessary between this weight and gravitation [, which is dependent on working gravitation of force] and mass [, which is not dependent on gravitation] unambiguously. The basic unite for the force working is Newton [N], for mass it is kilogram [kg]. I am sorry that the word weight was erased from the dictionary of the Czech language during this change hastily as the result of weight and as the original expression from which was deduced all next words – even in a metaphorical word’s sense [respect, serious, appreciate and so on]. Other states [Germany, The USA, The Great Britain and so on] retained the word ” weight ” in a common life wisely [see for example data on the goods or on the pages of Internet and so on] and the word mass they use only in the technical text.
The equal – armed scales were the first apparatuses for measuring of mass. They used during exchanging of goods in Babylon, in ancient Egypt and China. These scales had not the indicator of the balance yet – a small lingual. It was substituted by the horizontal position of arms, which was got by balancing with different weights.
In time of Roman’s Empire the scales existed only on one arm, provided with a scale along which was moving by weight [runner]. These scales are named ” prezmen ”. Some of these Roman’s scales had several eyes for hinging and several ranges then they were scales of several ranges. It was a great progress because it was possible to using one pair of scales in a great scale of weight and it was possible with only one pair of scales.
Next change came only in 1669, when the member of The French Academy of Science professor Gilles Persone de Roberval invented so called Equator – scales. This construction was spread very later and [after they were adjusted by weight man Beranger in 1847] it was used after The Second World War yet. They were called handle _ weights commonly. They had two dishes and they had to be weighted up for long time again. They had still small languages and were quite accurate.
Approximately in a half of 19 century the principle of Roman’s ‘ prezmen’ were revived and the runner’s scales were in a fashion again, that time they were constructed as the stationary the most often as the table [kitchen] or personal [at the doctor]. Moving of the weight set up the weights, but the scales were two here, rough and fine.
The weights working on a gradient principle were the last construction, which used handles. These quick – sales were started to produce at the beginning of the 20-century. Their advantage was in it that the burden could be only put on the saucer and the scales showed themselves on the scale some value after turning aside. These classical scales have been using till present, which have been using in many shops and in industry yet.
The handle scales are rather complicated and sensitive and there is manifested certain inertia at them especially. For it the scales based on another principle were constructed especially for the springy scales. Most of them are famous as the kitchen or tread personal ones, where the scale is rotating in a small window. Here is used the principle of pressing of spring.
The modern laboratory scales
(picture from http://www.veit.cz/LabVahy.html)
