The compact Apogee Instruments model MQ-100 light meter is the latest generation of basic handheld quantum meter featuring a state-of-the-art quantum sensor built right into the top of the meter.  The MQ-100 features a greatly expanded, stable LCD display which prominently shows instantaneous Photosynthetic Photon Flux (PPF) units directly as µmol m^-2 s^-1. The new display also indicates selectable modes for light source and data capturing or logging and as well as the currently displayed data sample number.  Modes and on/off are selected with five graphically rendered tactile membrane switches which provide superior reliability under field conditions.  The MQ-100 is factory-calibrated for both artificial and natural light sources, i.e. electric or sunlight.  

 The handheld meter comes dual-calibrated for measuring PPF under both electric lighting sources or sunlight.  The MQ-100 may used to measure PPF levels from other sources for which it was not initially calibrated.   The instructions include a list of  correction factors  to easily convert readings obtained from other light sources such as sunlight,  incandescent, high pressure sodium and metal halide lamps.