Giới Thiệu · ResoScale
ResoScale is the first weight scale app based on a mass resonance in the Market. This measurements method let you weigh almost everything and almost everywhere with an appropriate spring. You can achieve a relative error less than 1% of the calibration weight. The weight is calculated by comparing current oscillation frequency and the frequencies of calibration points. A spring can be any form (spiral or flat) and of any material (metal, wood, plastic or elastic band) with a neglecting damping.Instructions: Attach a mass to the one end of the spring. The other end of the spring is connected with a rigid support. If the measured weight is less than your phone weight then switch an active sensor to a magnetometer. Put a small magnet on the spring near to the weight. Place the phone separately from it in the magnetic field. In other case you may put the phone on the mass, switching sensor to an accelerometer. Set the spring oscillate by releasing the weight or by giving the spring small pushes near the rigid end of it. Supported frequency range is 0.2...5 Hz for now. The curve of the oscillation and the graph of Fast Fourier Transform (FFT) let you guess the quality of the oscillation. Your goal is to clear sinus without a higher harmonic. Avoid double frequencies of the oscillation on the magnetometer case by changing the position of a phone or a magnet. You must save at least two calibration points for weighing. To compensate the non-linearity due to the mass of the spring, you can calibrate the midpoint with half of the calibration weight.
Features: Three point calibration; Sensors: accelerometer or magnetometer; Relative error less than 1%; Weight from milligrams to tons; Changeable Quality factor, unit, currency and price; Calculation of the sum; A tare and hold buttons.
