Actinometer is a measurement device use to measure solar radiation. An actinometer is a chemical system or physical device which determines the number of photons in a beam integrally or per unit time. This name is commonly applied to devices used in the ultraviolet and visible wavelength ranges.
What device, invented by Peter Cooper Hewitt in 1902 and obsolete by 1975 with the introduction of devices such as the silicon diode and thyristor, converts alternating current to direct current by means of putting electricity through vapor?
What device measures its the proper acceleration relative to freefall, and is increasingly used in portable electronic devices and video game controllers to detect the orientation of the device or provide game input?
What is the name for a net of fine lines or fibres in the eyepiece of a sighting device, such as a telescope, a telescopic sight, a microscope, or the screen of an oscilloscope?
