The reseach of speedometer measuring apparatusSHI Dong-xing 91245 Armies and 80 Elements,Huludao 125000, China Abstract:This text introdues one kind speedometer check-up device in succession adjustable standard rotational speed （0 -3000） r/min, this device adopts the digital control method, combine the accurate rotational speed sample unit and electrical machinery constant speed control circuit, has ensured the high stability of the standard rotational speed signal, the device is used for checkup the speedometer mainly.[著者文摘]
Key words:digital calsed coop; axamination ;analog control
