Vibration

The behavior of a machine's mechanical components as they react to internal or external forces. Magnitude of cyclic motion; may be expressed as acceleration, velocity, or displacement. Defined by frequency and time-based components.

Vacuum Annealing

Annealing carried out at subatmospheric pressure.

Vacuum Carburizing

A high-temperature gas carburizing process using furnace pressures between 7 and 55 kPa during the carburizing portion of the cycle.

Vacuum Furnace

A furnace using low atmospheric pressures instead of a protective gas atmosphere like most heattreating furnaces. Vacuum furnaces are categorized as hot wall or cold wall, depending on the location of the heating and insulating components.

Vacuum Nitrocarburizing

A subatmospheric nitrocarburizing process using a basic atmosphere of 50% ammonia/50% methane, containing controlled oxygen additions of up to 2%.

Vacuum Deposition

The electrical application of a layer of one material (such as a metal) to the surface of another (the substrate), carried out in a vacuum chamber (e.g., evaporation and sputtering).

Vacuum Impregnation

The impregnation of a device (such as a capacitor, transformer, or choke coil) in a vacuum chamber. The process causes the pores in the device and its insulating materials to be completely filled with the impregnant.

Variable Capacitor

A capacitor that can be adjusted from a low value (practically zero) to some maximum value. A step-type unit contains a number of fixed capacitors that can be switched in parallel with each other until, at the last step, all are in parallel. A continuously variable unit has a provision for moving one plate or set of plates, relative to another plate or set of plates; or one plate might be moved, with respect to another, so that the distance between them is changed. In a voltage-variable capacitor (such as a varactor), capacitance varies in accordance with an applied direct-current voltage.

Variable Inductance Transducer

A transducer in which a monitored quantity causes the inductance of a coil to vary proportionately. The coil thereby offers a varying impedance to an alternating-current supply voltage.