FOR SCIENTISTS & SERIOUS GROWERS - Designed by world-renowned crop physiologist, Bruce Bugbee, PhD, the SQ-520 full-spectrum quantum USB sensor is the premium tool of choice among leading scientists and growers for accurately measuring the photosynthetically active radiation (PAR) from all light sources.
QUALITY QUANTUM SENSOR - Unlike cheaper LUX or footcandle sensors which are sometimes marketed as grow light sensors, but are meant for measuring light for human vision, our sensors feature a laboratory-grade PPFD (photosynthetic photon flux density), or “quantum,” optical detector precisely calibrated to measure the light intensity in µmol m-2 s-1 of the specific color wavelengths emitted by LEDs, HPS, MH, sunlight, and other light sources utilized by plants for photosynthesis.
USB COMPATIBLE - Smart quantum sensor can be connected directly to a computer (Windows or macOS X) for taking spot measurements or graphing and datalogging real-time PPFD using the included ApogeeConnect software. The sensor can also act as a stand-alone PAR datalogger by simply connecting it to most standard 5 V DC USB power plugs.
EXTREMELY ACCURATE & STABLE - PThe sensor precisely measures and combines the intensity of all photons between 400 and 700 nm to give a single PAR reading in µmol m-2 s-1 within 5 % uncertainty. Unlike hobby-grade PAR sensors, our sensor has a stable, accurate calibration with an accuracy drift rate of less than 2 % per year.
RUGGED & EASY TO USE - Quantum sensor head is machined aluminum and potted solid with epoxy for years of use in harsh environments, including underwater. Internal memory within the sensor head is capable of storing 10,000 user-specified periodic measurements that can be downloaded as a CSV file to a computer for analysis. For full-spectrum measurements with both a meter and a sensor, please see our MQ-500.
MADE IN THE USA - All sensors are designed, built, and calibrated at our headquarters in Logan, Utah, USA. Apogee Instruments has been creating research-grade instruments for scientists and serious growers for over 25 years. All sensors are backed by our industry leading four-year warranty and supported by our world-class, US-based customer support team.
FOR MORE PRODUCT INFORMATION, CHECK OUT THESE LINKS
• Software
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The improved spectral response of the SQ-520 increases the accuracy of LED measurements, compared to our previous models, making it ideal for use with all natural and electric light sources.

Software Overview

The sensor can be connected to a desktop, laptop, or tablet computer via USB 2.0 type A plug, to be used with the Apogee software (windows compatible, XP and later; Mac compatible, 10.10 and later). The included ApogeeConnect software gives the user control of data logging and calibration settings, provides a real time output display and graph of PPFD measurements and allows the data set to be saved as a csv file.
Click here to download the ApogeeConnect software for USB sensors.
The sensor has internal data storage capability with the ability to hold up to 10,000 measurements. This allows the sensor to collect data while connected to most stand-alone 5 V DC power supply such as a USB wall adapter.