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 (fō′tō-to͞ob′, -tyo͞ob′)
An electron tube with a photosensitive cathode.


(Electronics) a type of photocell in which radiation falling on a photocathode causes electrons to flow to an anode and thus produce an electric current


(ˈfoʊ təˌtub, -ˌtyub)

an electron tube with a photosensitive cathode, used like a photocell.
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References in periodicals archive ?
Microscope optical trinocular with a phototube (a biological working microscope) consisting of: a
A separate program, assuming equal phototube efficiencies, was developed for evaluating the effects of varying different input and model parameters.
Tenders are invited for Fluorescent microscope (axio imager a2) including illumination system, digital camera and imaging software or acceptable alternate, meeting the following minimum specifications: an imager stand, nosepiece, illuminator, mechanical stage, specimen holder (76 x 26 mm, immersion), binoc phototube, eyepiece, and dust protection cover; condenser; optics (plan-neofluar 5x, 10x, 20x, 40x and plan-apochromat 63x); accs for fluorescence (fl/hd light train man imager, reflector turret, shutter for transmitted light, attenuator, diaphragm slider w/luminous field).
The phototube and photometer permit determination of the null point with a high degree of sensitivity.
For better timing of showers, a third reflector, this one 7 meters across and reflecting light on a similar phototube array, will be placed 240 meters from the other two.