Analog Engine Tachometer (Auto Range Type)
AR-7240B - Ono Sokki
The AR-7240B is an analog engine tachometer featuring the automatic full scale switching function. When engine rotation is measured in the low scale, such as idling speed adjustment, it can be observed in the low range with 200 r/min scale. And the meter scale can be switched automatically to the high range with 10,000 r/min scale when engine rotation is increasing up into high speed load domain.