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Comprehensive instruments are diagnostic devices that integrate multiple testing functions into one, making it more convenient for on-site fault diagnosis with multi-parameter detection. Currently, there are mainly six combinations of testing functions for such instruments: ① combination of pressure and flow; ② combination of pressure, flow, and temperature; ③ combination of pressure, flow, and power; ④ combination of pressure, flow, and rotational speed; ⑤ combination of pressure, flow, temperature, and power; ⑥ combination of pressure, flow, temperature, and rotational speed. Due to the integration of various detection functions, some literature refers to this type of instrument as a “hydraulic multimeter.”
Several domestic units have developed comprehensive hydraulic testing instruments. For example, the CYJ-B type hydraulic system monitoring instrument combines pressure, flow, and rotational speed. This instrument mainly consists of a connector body, sensors, and a signal processor. The testing accuracy is: pressure ± 0.7%, flow ± 1.5%, rotational speed ± 0.2%. The CHY12D hydraulic multifunctional testing instrument combines pressure, flow, and temperature. This instrument mainly consists of a turbine flow meter, pressure sensor, temperature sensor, and YQY-12D testing device, with the analog output values for the three parameters being: pressure 0-5V (0-25MPa), flow 0-5V (0~5kHz), temperature 0~5V (0~100℃). Additionally, there are hydraulic system diagnostic instruments and multi-point pressure flow testing instruments, all of which have multi-parameter detection capabilities and have been successfully used for on-site testing and fault diagnosis of various equipment.
There are many foreign comprehensive hydraulic testing instruments. For instance, the American company Flo-tech produces three series: PFM6, PFM6BD, and PFM8, with a total of thirteen specifications, whose detection functions combine pressure, flow, and temperature, among which the PFM8 series can directly display power. The testing accuracy is ± 1%, and the test results can be displayed digitally. The heaviest PFM8-200 model weighs only 91N. The American company Denison also produces the DHCR digital hydraulic detector with eight specifications, combining pressure, flow, and temperature detection functions. This instrument has a flow testing range of 0.1~800L/min and can reach a maximum pressure of 420MPa, with test results displayed digitally.
Note: Please contact the author for authorization to reproduce. Author: Professor Huang Zhijian, Guangzhou Xinuo Machinery Co., Ltd., 020-82333916
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