1. A glass, silica, or porcelain tube, that is resistant to high temperatures, which is a component of a combustion train.
2. A tube, resistant to high temperatures and usually composed of glass, silica, or porcelain.

It is used to hold samples during pyrolysis (decomposition of complex molecules by heat) or elemental (fundamental) analysis.

An evacuated enclosure (removal of gases and vapors) containing a gas at low pressure, through which current can flow when sufficient voltage is applied between metal electrodes in the tube.

A gas-filled tube used in plasma physics to suddenly ionize a gas.

A capacitor bank charged to a high voltage is discharged into the gas at one tube end to ionize and heat the gas, producing a shock wave that may be studied as it travels down the tube.

An instrument consisting of an airtight quartz tube that holds the material to be analyzed.

When a high-frequency electrostatic field, generated by microwaves, is applied to the tube, it emits energy of a wavelength that is identical to that of the contained material.

1. A cathode ray tube in which the beam of electrons produced in the tube's filament is deflected by a magnetic field.
2. A cathode-ray tube in which electromagnetic deflection is used on the electron beam.

1. A component in an electrometer that has a high input impedance and a low control-electrode conductance, facilitating the measurement of extremely low direct current or voltage.
2. A high-vacuum electron tube having a high input impedance (low control-electrode conductance) to facilitate the measurement of extremely small direct currents or voltages.

1. A tool which projects an optical image generated by electromagnetic radiation from a photosensitive surface onto a fluorescent screen.
2. An electron tube which reproduces on its fluorescent screen an image of the optical image or other irradiation pattern arriving at or striking its photosensitive surface.
3. A cathode-ray tube that has a photoemissive mosaic upon which an optical image is projected, and an electron gun to scan the mosaic and to convert the optical image into a corresponding electrical current.

A phototube with one or more dynodes (electrodes the primary function of which is secondary emission of electrons) between its photocathode (photosensitive surface that emits electrons when exposed to light or other suitable radiation) and the output electrode.

The electron stream from the photocathode is reflected off each dynode in sequence, with a secondary emission adding electrons to the stream at each reflection.

1. A small cathode-ray tube having a fluorescent screen on which the pattern varies with the voltage applied to the grid that is used chiefly in radio receivers to indicate accuracy of tuning.
2. A special-purpose electron tube in which electrons are accelerated by high-voltage anodes, formed into a beam by focusing electrodes, and projected toward a phosphorescent screen that forms one face of the tube.

To form a display, or image, on the screen, the electron beam is deflected in the vertical and horizontal directions either by the electrostatic effect of electrodes within the tube or by magnetic fields produced by coils located around the neck of the tube.

3. A type of recording-level indicator using a luminous display in a special tube.

The display is usually like an "eye" with a keyhole in the middle, and the maximum recording level corresponds to the closing-up of a slot at the bottom of the keyhole which is superseded by meters in current-model recorders.

A circuit which uses electron tubes to provide the additional power needed to increase a signal: "An electron-tube amplifier provides the required increase in signal strength."

1. A tool which transforms direct current into a radio frequency by passing it through an electron tube in an oscillator circuit.
2. A generator in which direct-current (DC) energy is converted to radio-frequency (RF) energy by an electron tube in an oscillator circuit.

An electric heating element for supplying heat to an indirectly heated cathode in an electron tube.

1. The relationship among the various parameters in an electron tube when voltage and current are constant.
2. The relation between two of variables of an electron tube; such as, electrode voltage and electrode current of an electrode with all other voltages maintained constant.

1. An instrument in which electrons move through a vacuum or gaseous medium within a gas-tight chamber; used to generate, to amplify, and to correct electric oscillations and AC currents.
2. An electronic apparatus that consists, typically, of a sealed glass bulb containing two or more electrodes.

It is used to generate, to amplify, and to rectify electric oscillations and alternating currents.

3. An electron device in which electricity is conducted by electrons moving through a vacuum or gaseous medium within an hermetically sealed envelope.

A tube can perform rectification, amplification, modulation, demodulation, oscillation, limiting, and a variety of other activities.

Examples include cathode-ray tubes, gas tubes, phototubes, and vacuum tubes.

1. An instrument; such as, a klystron (type of vacuum tube used as an amplifier), oscilloscope tube, or television picture tube, which functions through the generation of one or more electron beams.
2. An electron tube whose performance depends on the formation and control of one or more electron beams.

1. An electron tube consisting of a sealed glass or metal enclosure from which the air has been withdrawn.

It was used in early electronic circuitry to control a flow of electrons.

2. An electronic instrument which consists, typically, of a sealed glass bulb containing two or more electrodes.

It is used to generate, to amplify, and to rectify electric oscillations and alternating currents.

A relay which employs electronic tubes as components.

1. The voltmeter whose sensitivity is increased by amplification.
2. A voltmeter that uses the rectifying and amplifying properties of electron devices and their associated circuits to secure desired characteristics; such as, high-input impedance, wide-frequency range, crest indications, peak-to-peak indications, and so on.

It is called a "vacuum-tube voltmeter" when its electron devices are vacuum tubes.

An electron tube which includes an electron multiplier.

1. An image tube used in astronomy in which the electron image formed by the tube is recorded directly on a film or on film plates.
2. An instrument consisting of an electron tube in which an accelerated beam of electrons produces images on a fine-grain photographic emulsion.

An image produced with this tool.

A couple (component used to transfer energy from one circuit to another circuit) specifically designed to be inserted between an electron tube and an input or an output tool, as between a magnetron and a transmission line.

1. An electron tube which has mutually interacting streams of electrons with different velocities that cause a signal modulation to change progressively along the length of the electron streams.
2. An electron tube in which stream of electrons having different velocities interact and cause a progressive change in signal modulation along their length.

A cathode-ray tube in which electrostatic deflection is used on the electron beam.

A cathode-ray tube is a vacuum tube in which a stream of electrons is accelerated and focused in a beam that produces traces of light on a screen at one end of the tube and which is used in television sets, computer monitors, and as an indicator in radar sets, etc.

An electron tube in which information is stored with electric charges.

An electron tube using cathode-ray beam scanning and charge storage for the introduction, storage, and removal of information.

The numerous divergent fringelike processes on the distal part of the infundibulum (funnel-shaped structure) of the uterine tube.

A tube formed or a cylinder formed in some flowers by the fusion of the perianth (floral envelope) and the stamens (pollen-bearing organs of the flower).

An electrometer is a device that uses, as an amplifier, a vacuum tube having a very high input impedance which is the measure of the opposition that an electrical circuit presents to the passage of an electric current when a voltage is applied.

A gas tube whose voltage drop is approximately constant over the operating range of current and is also relatively stable with time at fixed values of current and temperature.

1. A glow-discharge tube that maintains an essentially constant tube voltage drop over the operating range of current.
2. A glow-discharge tube in which the tube voltage drop is approximately constant over the operating range of current.

It is used to maintain an essentially constant direct voltage in a circuit despite changes in line voltage or load.

A gas-filled tube normally working with a glow discharge in that part of the characteristic where the voltage is practically independent of current.

An oscillator tube that has an operating frequency which can be varied by changing one or more of the electrode voltages; as in a backward-wave magnetron.