Upaya Peningkatan Resolusi Sensor Load Cell Pada Timbangan Elektronik
Electronic scales are weight measurement instrument that are widely used both in the laboratory
and in the industry. One of the main sensors of electronic scales is Load Cell. Direct use of Load Cell only
resulted in standard resolution of load cell and the ADC system used so that the scale’s resolution is quite low because it is only determined by Load Cell’s measurement range and ADC resolution in which ADC’s dynamic range could not be achieved. This study done an electrical effort to increase the scale’s resolution so that the wighing accuracy could be better. Improving the resolution is done with electronic signal processor and conditioners using summing and leveling amplifiers and eliminating noise is done by filtering. Data processing was done by comparing resolution value from Load Cell with and without signal conditioning. Load Cell with weight range 0-5kg using 200x amplification resulted in 113 mV – 1200 mV output. Using standar resolution ADC of 20mV/bit, the result will be 0000 0110 until 0011 1110. By adding Levelling Amplifier circuit, the output will be 48 mV for 0 kg wight and 4,87 V for 5kg weight. ADC result in this condition is from 0000 0010 to 1111 1100. ADC usage without levelling is 22% and with levelling is 98%. Without levelling, weight resolution is 89 gr/bit and with levelling is 20 gr/bit. Weight resolution increase to 345%.