Assessment of External Factors on the Accuracy of Ultrasonic Sensors for Water Level Measurement in Peatlands

Peatlands function as vital ecosystems in the world and the decrease in water level can make peatlands that initially function as water and carbon stores into sources of emissions that cause the soil surface to dry out and cause natural disasters. In some cases, dry peatland due to lowering of the groundwater level. Therefore, a method is needed to measure the water level accurately so that later it can be useful to maintain the water level with solutions from experts. This study aims to determine the effect of external factors on the accuracy of ultrasonic sensors HY-SRF05, JSN-SR04T, and US-100. Calculation of accuracy by comparing the sensor value with manual tools to get the relative error value and calculating the correlation value using the analysis of the coefficient of determination $( \mathrm{R}^{2})$. Accuracy results for measuring water level indicate that the US-100 ultrasonic sensor is more accurate than the HY-SRF05 and JSN-SR04T sensors. The relative error value of US-100 is 0.93%, HY-SRF05 is 2.13% and JSN-SR04T is 2.83%. There is a significant influence of external factors on the accuracy of ultrasonic sensors in measuring water levels in peatlands. Ultrasonic sensor HY-SRF05: air temperature 0.801, humidity 0.8819, wind speed 0.951, soil temperature 0.7592, and soil humidity 0.222. JSN-SR04T ultrasonic sensor: air temperature 0.9234, humidity 0.6681, wind speed 0.7831, soil temperature 0.5092, and soil humidity 0.4685. US-100 ultrasonic sensor: air temperature is 0.8224, humidity is 0.6275, wind speed is 0.7471, soil temperature is 0.4667, and soil humidity is 0.511.