DESIGN, CONSTRUCTION AND IMPLEMENTATION OF DIGITAL DUAL-SCALE MEASURING MACHINE USING MICROCONTROLLER

A digital dual-scale measuring machine was constructed consisting of two identical ring magnets
coupled in repulsive configuration and a microcontroller. The two magnets in repulsive mode
behaves as an elastic spring obeying Hooke's magnetic law provided the elastic limit of the magnets is
not exceeded. The dual-scale machine with upper scale limits of mass 1.2 kg and extension 1.5 cm
was used to measure assorted masses of objects and their corresponding extensions. Using the linear
relation between mass and extension, the following magnetic quantities were determined: magnetic
force constant 8244.3 N/m, push strength of the magnet 44.15 N, pole strength 588.22 Am, magnetic
2 dipole moment 23.53 Am , magnetization 138762.70 A/m, and remanence 0.1744 T. In addition, the
product moment correlation coefficient between the actual mass and measured mass is 0.9926 and the
cumulative power consumption of the constructed machine is 4.25 watts.