- Отрасли: Aviation
- Number of terms: 16387
- Number of blossaries: 0
- Company Profile:
Aviation Supplies & Academics, Inc. (ASA) develops and markets aviation supplies, software, and books for pilots, flight instructors, flight engineers, airline professionals, air traffic controllers, flight attendants, aviation technicians and enthusiasts. Established in 1947, ASA also provides ...
A device used to generate a small electrical current. A thermocouple is made up of two dissimilar metal wires, such as iron and constantan, copper and constantan, or chromel and alumel. The ends of these wires are joined to form a loop. Electrical current flows through the wires when there is a temperature difference between the junctions, the points at which the wires join. The amount of current flowing in the loop is determined by three things:
# The types of metals used for the wires
# The temperature difference between the two junctions
# The resistance of the thermocouple wires
Iron and constantan or copper and constantan thermocouples are used to measure the cylinder head temperature of reciprocating engines, and chromel and alumel thermocouples are used to measure the exhaust gas temperature in both reciprocating and gas turbine engines.
Industry:Aviation
A device used to generate DC electricity to produce electromagnetism in the field of an alternator or generator.
Industry:Aviation
A device used to light an oxy-gas welding torch. The lighter consists of a small piece of flint that can be rubbed against a piece of rough, hardened steel. A metal cup behind the steel prevents the flame from reaching out and burning anything as the torch is being lit.
Industry:Aviation
A device used to lock the flight controls of an aircraft so they cannot be damaged by the wind. Internal locks hold the control stick or wheel and the rudder pedals, rather than clamping the control surfaces themselves.
Industry:Aviation
A device used to lock the flight-control surfaces of an aircraft in their neutral position when the aircraft is on the ground.
Control locking devices normally have some type of warning flag to direct attention to the fact that they are installed or engaged. This prevents their being left in place when the aircraft is readied for flight.
Industry:Aviation
A device used to make a temporary connection to an electrical circuit. The contacts of a banana plug are springs having the general shape of a banana. These springs press out against the walls of the banana jack to make a low-resistance contact.
Banana plugs are installed on the leads of test instruments such as volt-ohm-milliammeters (VOMs).
Industry:Aviation
A device used to measure rotational speed by the use of a stroboscopic light. A brilliant light which flashes at a controlled rate is shone on the rotating object. When the light is adjusted to flash at the same rate the object is rotating, the object appears to stand still. The flash rate of the light is calibrated in terms of revolutions per minute (RPM).
Industry:Aviation
A device used to measure the amount of physical strain (deformation caused by a stress) in a piece of material. A strain gage is made of very fine wire mounted between two pieces of tissue paper, about the size of a postage stamp. The strain gage is bonded (glued) to the material in which the strain is to be measured, and the two ends of the wire are connected into a sensitive resistance-measuring bridge circuit.
When the material on which the strain gage is mounted is under a tensile stress, the wire in the strain gage stretches — it becomes longer and thinner, and its resistance increases. When the material is under a compressive stress, the wire becomes shorter and larger in diameter, and its resistance decreases.
The change in resistance is proportional to the amount of strain in the material, and the amount of strain is proportional to the amount of stress causing it.
Industry:Aviation
A device used to move a liquid from a container, over an edge higher than the level of the liquid, down to a lower level. A curved tube is put into the liquid, and some form of mechanical force is applied to start the liquid flowing through the tube. A suction is often put on the end of the tube to start the liquid flowing.
When the flow is started, atmospheric pressure forces the liquid from the higher container into the tube, and the weight of the liquid flowing through the tube to the lower level keeps the liquid flowing.
Industry:Aviation
A device used to produce an accurate amount of pressure to calibrate pressure-measuring instruments. Oil pressure built up in the tester is applied to a cylinder fitted with a free-floating piston. This piston has an accurately known area and is loaded with an accurately known weight.
The amount of pressure needed to raise the piston is found by dividing the weight being lifted by the area of the piston. This pressure is applied to the gage being calibrated, and the gage is adjusted to read this amount.
Industry:Aviation
