- frequency measurement by stroboscope
- 闪光测频
English-Chinese electricity dictionary (电气专业词典). 2013.
English-Chinese electricity dictionary (电气专业词典). 2013.
Frequency — For other uses, see Frequency (disambiguation). Three cyclically flashing lights, from lowest frequency (top) to highest frequency (bottom). f is the frequency in hertz (Hz), meaning the number of cycles per second. T is the period in seconds (s) … Wikipedia
Measuring instrument — Captain Nemo and Professor Aronnax contemplating measuring instruments in Twenty Thousand Leagues Under the Sea … Wikipedia
Gramophone record — A 12 inch (30 cm) 33⅓ rpm record (left), a 7 inch 45 rpm record (right), and a CD (above) A gramophone record, commonly known as a phonograph record (in American English), vinyl record (in reference to vinyl, the material most commonly used after … Wikipedia
Life Sciences — ▪ 2009 Introduction Zoology In 2008 several zoological studies provided new insights into how species life history traits (such as the timing of reproduction or the length of life of adult individuals) are derived in part as responses to… … Universalium
Electron — For other uses, see Electron (disambiguation). Electron Experiments with a Crookes tube first demonstrated the particle nature of electrons. In this illustration, the profile of the cross shaped target is projected against the tube face at right… … Wikipedia
High speed photography — [ Eadweard Muybridge, first published in 1887.] High Speed Photography is the science of taking pictures of very fast phenomena. In 1948, the Society of Motion Picture and Television Engineers (SMPTE) defined high speed photography as any set of… … Wikipedia
Optical chopper — An optical chopper is a mechanical device which periodically interrupts a light beam. Three types are available: variable frequency rotating disc choppers, fixed frequency tuning fork choppers, and optical shutters. A rotating disc chopper was… … Wikipedia
tachometer — tachometrically /tak euh me trik lee/, adv. tachometry, n. /ta kom i teuhr, teuh /, n. 1. any of various instruments for measuring or indicating velocity or speed, as of a machine, a river, or the blood. 2. an instrument measuring revolutions per … Universalium