The MQ-650 handheld underwater specific photosynthetically active radiation meter is based on the MQ-610 and has a built-in correction factor in the firmware for underwater measurement, making it very suitable for measuring underwater photosynthetically active radiation, especially the photon flux of artificial light sources (lights) underwater. It can be used to measure the total ePAR intensity above the plant canopy in all growth environments, monitor and regulate growth light, and study plant morphogenetic activity and photobiology.

The MQ-650 adopts a new ePAR sensor, which extends the spectral measurement range to 394nm~747nm (± 5nm), with a range of 4000 μ mol/m²/s， Significantly improved its measurement accuracy for LED light sources, which can better meet the measurement needs of natural light and artificial light sources. At the same time, it can achieve a 30m waterproof performance. Equipped with an AM-320 handheld probe, you can easily extend the sensor probe underwater or remotely for real-time measurement.

The MQ-650 recorder supports both automatic and manual measurement modes, and can store up to 99 measurement data. In automatic mode, the recorder measures every 30 seconds and automatically calculates the average of 60 30 second data points every 30 minutes and stores them. The Daily Light Integral (DLI) is calculated by averaging every 48 measurements over a 24-hour period.