By D. A. Taylor
Read Online or Download Marine Control, Practice PDF
Best engineering & transportation books
Additional info for Marine Control, Practice
Movement of the core to the left or right will result in an output voltage which will be directly proportional to the movement. Variable capacitance Variable capacitance transducers can use a number of methods to measure displacement. The area of the plates or the permittivity between them is varied when measuring large displacements. The gap between the plates is varied when measuring small displacements. SPEED Most speed measurement with regard to rotating machinery is angular velocity, which is usually expressed in revolutions per minute.
A very sensitive measurement is therefore possible. T h e parallel arrangement has the hot junctions at different temperatures and the cold junctions all at the same temperature. An average reading is therefore obtained. e. absolute zero, will emit electromagnetic radiation. T h e intensity of the radiation is a measure of the temperature of the body. T h e intensity ranges from the invisible infra-red rays to the visible light range and is measured using a radiation pyrometer. T h e temperature measuring range for radiation pyrometers is about 700 to 2000°C.
E. less then atmospheric. The needlemoving linkage is adjustable to enable calibration adjustments to be made as required. Diaphragms and bellows gauges A number of pressure measuring elements use the elastic properties of either a deflecting diaphragm or bellows. T h e diaphragm in its simplest form is a thin flat plate of circular shape. T h e plate is held around its circumference and when a pressure difference occurs between the two sides the diaphragm will deflect. Only very small movements will give a linear relationship between pressure and deflection.