Analysis of Temperature Stability Distribution in Waterbath Using Fuzzy Logic

Abstract

Waterbath is a tool used to create a constant temperature. This tool is used for incubation in microbiological analysis. The temperature is maintained according to the desired setting. The heating element is controlled by the heater driver. This module is made using Arduino Uno R3 as a minimum system and time controller, using a Fuzzy Logic controller as a temperature controller, and using a DS18B20 sensor as a temperature sensor. The processor is an Arduino UNO, and is displayed on a 20x4 Character LCD. The temperature selection is 30 ˚C, 35 ˚C, 37 ˚C, 40 ˚C, 45 ˚C, 50 ˚C, 55 ˚C, 60 ˚C. This study used a pre-experimental method with after only design research. The measurement results were carried out by comparing the module with a standard measuring instrument which produced the largest % error at a temperature setting of 30 ˚C which was 1.13%, this was related to the limit between the water temperature and the temperature setting which was too short which affected the DS18B20 temperature sensor reader which it takes time, to get a stable temperature reading. The minimum % error lies at 60 ˚C, because it takes a long time to reach the temperature setting so that the DS18B20 sensor reading is stable from the setting temperature, which is 0.26%. The % error timer value is 5.4% where the magnitude of the error is influenced by the number of DS18B20 sensors used and the delay of the microcontroller. Based on the results obtained, the temperature control error value is still below the tolerance limit because the error value is less than 3%.