DR BRUCE BUGBEE: Apogee PAR meters have been designed and refined by Dr. Bruce Bugbee, a world-famous crop physiologist. UNDERWATER ACCURACY: The MQ-510 ensures precise PAR measurements underwater by applying an immersion effect correction factor. It measures photons between 400 and 700 nm, providing a single PAR reading in µmol m-2 s-1 with less than 5% uncertainty. Its stable calibration boasts an accuracy drift rate of under 2% per year, unlike hobby-grade meters. FEATURES: The rugged detector measures photosynthetic photons from 400-700 nm from any light source by taking instantaneous or logged measurements; immersion correction-factor calibrated in for accurate UNDERWATER par-measuring. Bundle includes AM-330 UNDERWATER SENSOR WAND: This wand extends up to 36.25” (92cm), as measured from the end of the handle to the center of the mount making it ideal for reaching down into reef aquarium tanks. RUGGED DESIGN: The sensor head is made of machined aluminum and fully potted, making it waterproof and rugged. The tangle-free cable facilitates measurements over a large plant canopy, while still allowing the user to view the high-contract display screen. NOTE: Handheld-meter display is NOT waterproof MANUFACTURED IN THE USA: All meters are backed by our four-year warranty and supported by our US-based customer support team. Apogee MQ-510 Underwater Quantum Meter Designed for scientists and serious growers by world-renowned crop physiologist, Dr. Bruce Bugbee, Ph.D., the Apogee MQ-510 underwater quantum meter is the cutting edge standard in measuring underwater light levels. Product includes a complimentary Apogee neoprene carrying case. Trusted Quantum/PAR/PFFD Meter Scientists and serious growers all over the world trust the MQ-510 quantum meter to accurately measure photosynthetically active radiation levels from all light sources, which affects plant and coral growth. The quantum meter has a handheld display to display and store measurements. The sensor contains a precision silicon photodiode detector, a custom optical filter, and an acrylic diffuser all housed in a self-cleaning, dome-shaped, anodized aluminum sensor head. Multiple Applications This quantum PAR meter measures photosynthetic photon flux density (PPFD) for reliable light readings in natural waters and aquariums. MQ-510 quantum sensors are primarily used to measure PAR/PPFD in aquatic environments, especially saltwater aquariums where corals are grown. Three Measuring Modes The meter has a spot measurement, sample, and log mode and will record an integrated daily total in mol m-2 d-1. Sample mode will record up to 99 manual measurements and log mode will power the meter on and off to make a measurement every 30 seconds. Every 30 minutes, the meter will average the sixty 30 second measurements and record the averaged value to memory, up to 99 averages. Once full, it will overwrite the oldest measurements with new ones. A daily light integral will be recorded from the 48 averaged measurements for a day’s worth of readings and is downloadable via an Apogee AC-100 cable.