18WuD2x

dynatron frequency meter • dysprosium 223
dynatron frequency meter A heterodyne-type frequency
meter using a dynatron oscillator.
dyne Abbreviation, d. A unit of force. One dyne
(10 –5 newton) is the force that will give a mass of
1 gram an acceleration of 1 centimeter per second
per second. Compare NEWTON.
dyne-centimeter See ERG.
dyne-five In the Giorgi mks system, a unit of force
equal to 1 newton.
dyne per square centimeter Abbreviation, d/cm 2 .
A unit of pressure equal to 0.1 pascal (9.869 ×
10 -7 atmosphere).
dyne-seven A unit of force equal to 10 7 dynes.
dynistor A semiconductor diode that continues to
conduct after the forward voltage is reduced below
the normal threshold point. To stop the conduction,
a reverse voltage must be applied, or
voltage must be entirely removed from the device.
It is used in switching applications.
dynode In a photomultiplier tube, any of several
slanting electrodes that receives a beam of electrons
generated by the light-sensitive cathode
and reflects it, along with secondary electrons.
This amplifies the beam; the process is repeated
several times. Thus, the emission from the
Visible
light
−
Electron
beam
Photocathode
Dynodes
dynode
Dynodes
Load
+
Anode
cathode is greatly amplified when it reaches the
plate.
dysprosium Symbol, Dy. An element of the rareearth
group. Atomic number, 66. Atomic weight,
162.50. Dysprosium is a highly magnetic substance.