Development of a Low-Cost, Autonomous Pulse Amplitude Modulated (PAM) Chlorophyll Fluorometer for In-Situ Monitoring of Photosystem II Efficiency

TL;DR

This paper introduces a low-cost, autonomous PAM fluorometer capable of in-situ, large-scale monitoring of photosystem II efficiency in plants, offering comparable accuracy to commercial devices at a fraction of the cost.

Contribution

The work presents a novel, affordable, and compact PAM fluorometer that operates autonomously for extensive plant monitoring, filling a gap in existing commercial solutions.

Findings

Achieved measurement accuracy with R^2 = 0.95 compared to commercial sensors.

Cost of the prototype is approximately 150 EUR.

Device dimensions are 3 cm x 6 cm x 2 cm, weighing about 50 g.

Abstract

The quantum yield efficiency of photosystem II (PhiPSII) is an important parameter for assessing the photosynthetic performance and stress status of plants. Commercial PAM fluorometers can measure this parameter, but they are often expensive, bulky, or lack autonomous operation. This work presents the development of an autonomous PAM fluorometer designed to address these limitations and enable large-scale deployment. It supports high spatio-temporal monitoring of PhiPSII in forest canopies under a wide range of ambient light conditions. The prototype costs approximately 150 EUR, has dimensions of 3 cm x 6 cm x 2 cm, and weighs about 50 g. In side-by-side tests across three plant species, it achieved measurement accuracy comparable to state-of-the-art commercial sensors, with a correlation factor of R^2 = 0.95.