第一章：全静压系统仪表(国外英文资料).docVIP

第一章：全静压系统仪表(国外英文资料) Chapter 1: all static pressure system instruments Section 1 altimetables What principle does the barometer use to indicate altitude? It is the use of vacuum bellows feel pressure to indicate that the height, height change air pressure also changes, vacuum bellows expansion or contraction, after transfer institutions make long pointer rotation, long pointer rotation at the same time, through the reduction gear turns short pointer, thus points out the corresponding level. What altitude does the barometer indicate? How do you do that? The barometer can indicate relative height, standard pressure height, absolute height. Operation: a. relative height measurement: before departure, the pointer with adjustment knob set to zero, at this point, the air pressure should dial indicator scene at that time, in this way, after the plane took off, altimeter is indicated the relative height; If after the plane took off, the airport scene pressure changed, altimeter can appear error, at this point, as long as to inform the pilot, let him adjust knob dispatch of pneumatic dial readings to change the original scene at the airport after pressure altimeter is accurately indicates the relative height of the original airport again; Flying in plateau area, the scene pressure may be beyond the scale range of pneumatic dial, then dial is not enough air pressure, the scene pressure by index to reflect, of course, the indication is not the scene pressure but the airports standard, but the two are equivalent, so the index as long as at the airport on standard, indicating relative height problem is solved. B. measure the standard pressure height = the standard pressure height = relative pressure height + airport standard pressure height; C. absolute height measurement: measure the absolute height, make pneumatic dial points out that the sea level pressure, to do this, to know how much is sea level pressure, sea level pressure is the use of scene pressure and airport elevation