PERTANIKA JOURNAL OF SCIENCE AND TECHNOLOGY

Utilisation of low-cost sensor (LCS) for soil moisture measurement is increasing along with the advancement of integrated agricultural technology and environmental data collection. One such low-cost sensor, SKU:SEN0193, demonstrates that its measurement accuracy heavily depends on the calibration model. Unlike the commercial sensor, the LCS has less document related to the operation, especially the conversion equation to precisely estimate the soil moisture from the voltage records. Attaining LCS consistency is no straightforward task when many LCS had less been tested on the field at longer period to determine the durability attribute. The main challenge in applying the SKU:SEN0193 for soil moisture measurement is to determine the accuracy, reliability and suitability of records in long-term measurement routine. The present study focussses on developing a calibration model using field gravimetric measurement for accuracy assessment and to evaluate sensor reliability and durability through long-term calibration exercises. Results showed that calibration model produces promising relation to the gravimetric soil moisture with R2=0.81 and RMSE=1.02 %. Though, the SKU:SEN0193 encountered an average output difference of about 7% variation between measurement records that manifested in kurtosis peaks and significant changes in skewness distribution patterns. This study found that SKU:SEN0193 exhibits good durability through the consistent negative skewness distribution patterns and negligible differences in kurtosis peaks of when the sensor did not experience malfunction or significant deviation during the several tests.