BACKGROUND: Measurement equipment was developed for inorganic nutrient concentration inside the hydroponic culture medium with several macro- and micro compositions, and applied for measuring the compositions of conventional medium.
METHODS AND RESULTS: Before the equipment development, sonicator and heater were manufactured to control temperature around of the module mixing with color reagent and target sample among the inorganic compositions. The measurement module and multi-sampler were also manufactured based on the COMS (Complementary Metal–Oxide Semiconductor) and installed inside the measurement equipment. Concentration of standard solution, value measured by the equipment, standard deviation or measured average value was used for estimating the accuracy and average recall of the equipment. Yamazaki solution samples of EC 0.5, 1.5 and 2.5 dS/m were offered to confirm the equipment accuracy and standard error.
CONCLUSIONS: It was suggested that the developed equipment could be automatically applied for measuring with above 96% accuracy and less than 5% standard errors of 12 macro- and micro compositions such as a NO3-N, PO43- or Fe.