To provide a rotational frequency measuring device which detects rotational frequency of an object, sets an upper limit and a lower limit according to the detected rotational frequency, and issues a warning, when the rotational frequency of the object deviates from the limits, by detecting a deviation.
A rotational frequency measuring device 10 comprises: a proximity switch 14 which detects rotational frequency of a measurement object; a control section 11 which receives a pulse signal from the proximity switch 14; and a display 34 which is connected to the control section 11. The rotational frequency measuring device 10 obtains the rotational frequency of the measurement object from the pulse signal through rotational frequency calculation means installed in the control section 11, and displays the rotational frequency of the measurement object on the display 34. The control section 11 has: reference rotational frequency setting means which enables a button operation to set the measured rotational frequency as reference rotational frequency; upper and lower limit setting means which sets an upper rotational frequency limit as well as a lower rotational frequency limit from the reference rotational frequency; and warning signal generation means which issues a warning output when rotation of the measurement object is beyond a range from the upper and rotational frequency limit to the lower rotational frequency limit.
Yoshihiro Kurita
Takayuki Imanaka
Next Patent: EMERGENCY VEHICLE ROUTE GUIDANCE DEVICE