单项选择题
A.the absolute pressure B.the gauge pressure C.the vacuum pressure D.the differential pressure
Movement of the diaphragm or bellows is （） by a linkage...
单项选择题Movement of the diaphragm or bellows is （） by a linkage to a needle or pointer display to indicate the differential pressure between two sides of the diaphragm or bellows.
A.measured B.recorded C.transferred D.controlled
When two different metals are joined to form a closed c...
单项选择题When two different metals are joined to form a closed circuit and exposed to different temperatures at their junctions （） which can be used to measure temperature.
A.a current will flow B.a power will develop C.a heat will flow D.a pressure will produce
（） is provided to alternators, in the event of prime mo...
单项选择题（） is provided to alternators, in the event of prime mover failure to ensure that the alternator does not act as a motor.
A.Reverse current protection B.Reverse power protection C.Synchronising device D.Frequency meter
