| 摘要 |
Apparatus and method are disclosed for measuring and displaying predetermined characteristics of reciprocating piston machines. In the preferred embodiment, the predetermined characteristics comprise indicated horsepower, crankshaft angle and piston position. The apparatus comprises a central processing unit, memory devices, keyboard assembly, display controller, display unit, sweep generator, pressure data acquisition and scaling system, shaft encoder and pressure transducer operatively connected by an address bus and a data bus to measure and display the predetermined characteristics. A method is provided whereby an electrical signal is generated which is proportional to the instantaneous position of a designated piston in the reciprocating piston machine. A method is also provided whereby an electrical signal is generated which is proportional to the instantaneous angular position of the crankshaft with respect to a top-dead-center position of a piston in a predetermined cylinder of the reciprocating piston machine. Predetermined data is entered into the apparatus by the operator as well as from the pressure transducer and crank angle or shaft encoder attached to the engine/compressor which is to be analyzed. The sweep generator circuitry maintains an accurate sweep length for the display unit over the entire range of speeds from zero to the top speed of the engine or compressor being analyzed.
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