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The first postage meter device consisted of a manual crank, chain action, printing die, counter and lockout device. In 1902, he received a patent for "a hand-cranked gadget with two locking counters - one counting down the amount of postage remaining from the original amount purchased, the other counting up to show the total postage dispensed ...
The krypton-86 discharge lamp operating at the triple point of nitrogen (63.14 K, −210.01 °C) was the state-of-the-art light source for interferometry in 1960, but it was soon to be superseded by a new invention: the laser, of which the first working version was constructed in the same year as the redefinition of the metre. [126]
File:An Army at Dawn - The War in North Africa (book cover).jpg; File:An Eye For An Eye (book cover) by John Sack (1993).jpg; File:AnAmericanDilemma.jpg; File:Anatomy of an Epidemic-cover.jpg; File:Ancient Maya The Rise and Fall of a Rainforest Civilization book cover.jpg; File:Ancient Society (book).jpg; File:And the Band Played On (first ...
The 24-year-old from Brooklyn was the first to use a new technology called digitalization to capture images. Four decades later, we carry his invention in our pockets on our phones. Courtesy of ...
Arnold Orville Beckman (April 10, 1900 – May 18, 2004) was an American chemist, inventor, investor, and philanthropist. While a professor at California Institute of Technology, he founded Beckman Instruments based on his 1934 invention of the pH meter, a device for measuring acidity (and alkalinity), later considered to have "revolutionized the study of chemistry and biology". [1]
Analog multimeter Digital multimeter. A multimeter (also known as a volt-ohm-milliammeter, volt-ohmmeter or VOM) [1] is a measuring instrument that can measure multiple electrical properties. [2] [3] A typical multimeter can measure voltage, resistance, and current, [4] in which case can be used as a voltmeter, ohmmeter, and ammeter.
US 6657571, Gordon, Bernard M.; Weedon, Hans & Poulo, Louis R. et al., "Data acquisition system using delta-sigma analog-to-digital signal converters", published 2 December 2003 U.S. patent 6,188,745 CT scanner comprising a spatially encoded detector array arrangement and method
If you’re interested in learning about Tubman’s service in the Civil War, pick up “Harriet Tubman, Secret Agent,” a book by Tom Allen. You can also watch “Harriet,” the 2019 biopic ...