Testo-0560-0540-540-Lux-Meter-Illumination-Measuring-Device-Testo-0560-0540-P-The-540-Lux-Meter-from-Testo-can-be-used-to-measure-both-artificial-&-natural-light-&-provides-you-with-a-quick-&-easy-means-of-assessing-lighting-conditions-in-the-workplace-The-light-sensor-is-modelled-on-the-spectral-sensitivity-of-the-human-eye-&-is-ideal-for-use-in-a-variety-of-applications-P-P-This-compact-easy-to-use-meter-has-a-number-of-useful-functions-&-features-including-a-large-easy-to-