Need Help? Call us at 1-317-895-9005
or email us at

Proudly serving Aquarists since 1996

Apogee SQ-520 Full Spectrum Smart Quantum Sensor - USB Output

$341.25 was $ 455.00
Item #
Eligible for Free Shipping Program
In Stock

The new SQ-520 full-spectrum, smart quantum sensor can be connected directly to a computer via USB for taking spot measurements or graphing and datalogging real-time PPFD using the included software. The sensor can also act as a stand-alone PAR datalogger by simply connecting it to any standard 5 V DC USB power plug. 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.
The SQ-520 is used to measure incoming and reflected PPFD around plants and other organisms in outdoor environments, greenhouses, growth chambers, and underwater.
Refined Spectral Response
The improved spectral response of the SQ-520 increases the accuracy of LED measurements making it ideal for use with both natural and electric light sources.
The versatile SQ-520 can be used two ways - it can be connected directly to a computer for real-time measurements and data logging using the provided software, or it can be connected to a standard USB power source and act as a stand-alone datalogger capable of storing 10,000 periodic measurements internally that can be downloaded to a computer later for analysis.
No Datalogger Required
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. The included Apogee 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.
Internal Data Storage
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 a stand-alone 5 V DC power supply such as an independent battery pack or USB wall adapter.
Software Overview:
Resolution 0.1 µmol m-2 s-1
Calibration Factor custom for each sensor and stored int he firmware
Calibration Uncertainty ± 5 %
Measurement Repeatability less than 1 % ( up to 4000 µmol m-2 s-1
Long-term Drift less than 2 % per year
Non-linearity less than 1 % (up to 4000 µmol m-2s-1
Response Time software updates every second
Field of View 180 °
Spectral Range 389 to 692 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum)
Spectral Selectivity less than 10 % from 412 to 682 nm ± 5 nm
Directional (Cosine) Response &plusm; 2 % at 45 °, ± 5 % at 75 °
Azimuth Error less than 0.5 %
Tilt Error less than 0.5 %
Temperature Response -0.11 ±; 0.03 % C-1
Uncertainty in Daily Total less than 5 %
Detector blue-enhanced silicon photodiode
Housing anodized aluminum body with acrylic diffuser
IP Rating IP68
Operating Environment -40 to 70 C; 0 to 100 % relative humidity; can be submerged to depths of 30 m
Dimensions 24 mm diameter; 37 mm height
USB Cable 4.6 m (15 ft)
Mass sensor head weighs 90 g
Current Draw (when Logging) 5.1 mA
Warranty 4 years

Customer Reviews

You must be logged in to post a product review.

No more wagging it Mar 17, 2020
I've slowly built up my lighting on my 220g over the past year and currently up to a t5ho hybrid fixture with 4 kessils @12" centers. Was amazed to discover how low the par was for my poor frags with glass lids. Will likely start replacing kessils with G5s (love my xr15 blue). Anyways, this par meter does tge trick at a lower price point. The cable is nice and long. The only thing that i was disappointed in is the software says XP compatible, but wouldn't work for me so i had to use a newer full-sized laptop. I didn't try any if the logging features. Lastly, gotta love the service