Development of a low-cost multifunctional scale for the study of plant transpiration using the Arduino platform

We report the development of a low-cost multifunctional scale and its application in measuring plant transpiration. The equipment is easy to assemble and handle, being composed of a load cell, an Arduino microcontroller, and environmental sensors (light, temperature, and humidity). A program was developed to integrate all components and to enable data acquisition and storage on a memory card. To test the equipment, we measured plant transpiration as a function of irradiance and soil water content. As expected, transpiration rates increased at higher irradiance levels, and the values obtained using the multifunctional scale were similar to those obtained using an infrared gas analyzer. The equipment was also adequate to characterize the transpiration response to the suspension of irrigation, with the advantage of identifying the whole process with a high level of detail. We conclude that the equipment is promising, especially when considering its low cost. Furthermore, monitoring the response to drought with high temporal resolution can be fundamental for the identification of nuances in the control of transpiration throughout the day and night, which are difficult to obtain using single-point measurements.