Misura luminosità delle lampade ¶
By: ptorr on Giovedì 09 Dicembre 2021 13:36
Mi domandavo come venga misurata l'intensità luminosa di una lampada. Mi ècapitato questo interessante documento storico trovato su Shorpy
March 21, 1938. Washington, D.C. Purchasing on an average of 4 million electric light bulbs annually, Uncle Sam is probably one of the largest users of light in the country. The National Bureau of Standards sees that the government gets value received in purchases by continually testing the incandescent lamps to determine their life and the amount of light they give. Using a special machine designed by the Bureau, Louis Barbrow is shown measuring the amount of light given by a lamp