Researchers at King’s College London have converted an off-the-shelf product, usually used to determine whether car window tint is legal, into a scientific instrument that can measure leaf water content in seconds.
Comparable field instruments can cost many tens of thousands of pounds, while the standard laboratory approach requires leaves to be picked, oven-dried and weighed over many hours.
However, the modified device, which costs about £140 ($190) in total to build from readily available components, approached the performance of laboratory methods across six plant species, explaining at least 81% of the variation in leaf water content.









