Building material for breakwater* levee* breast wall* etc*

Apparatus and method for testing electronic system

PURPOSE:To measure the coefficient of friction of a magnetic tape accurately regardless of temperature and humidity variation by using a DC motor as a driving source for magnetic tape movement and a measuring instrument. CONSTITUTION:A weight 3 is suspended from one terminal of a magnetic tape 2, a reel hub 5 is arranged at the other terminal, and the DC motor 6 is fixed concentrically with the hub 5. The correlation between the current and torque of the DC motor is obtained prior to measurement. Said DC motor 6 has such a small torque constant that the difference in current is varied with fine torque variation. When a voltage is applied to the DC motor 6 for the measurement, the motor 6 turns as shown by an arrow (a) to pull up the weight 3. Then the current value is read to obtain a static and a dynamic coeffieient of friction between the magnetic tape 2 and a tape guide post 1. Further, the moving speed of the magnetic tape 2 is made constant by holding the voltage constant to obtain a high-precision measured value.

Building material for breakwater* levee* breast wall* etc*

Citations

Apparatus and method for testing electronic system

Measuring device for coefficient of friction

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