Low-cost weighing lysimeter: development, calibration, and evaluation

Abstract

Weighing lysimeters, which directly measure mass variations in the soil-plant system, provide high precision, but are typically costly, limiting their large-scale use. As an affordable alternative, six low-cost weighing lysimeters were developed, calibrated, and evaluated. The devices were built with low-cost materials and a modular design, integrating load cells with an Arduino microcontroller platform (ATmega 2560). The calibration with reference masses demonstrated excellent linearity, with determination coefficients (R²) ranging from 0.9890 to 0.9987, confirming a high measurement accuracy. The error parameters were also rigorously assessed, including hysteresis (up to 6.33 % of the full scale - FS), non-linearity (up to 10.92 % of the FS), and repeatability (up to 14.57 % of the FS). Despite the calibration consistency, the analysis of these errors and the maximum absolute error (up to 10.77 % of the FS) revealed limitations in achieving the precision required for highly sensitive scientific applications.

KEYWORDS: Arduino platform, efficient irrigation, water management.