Apogee USB Quantum Sensor

Apogee USB Quantum Sensor

  • $399.95
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Product Description

The new SQ-420 smart quantum sensor can be connected directly to a computer 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-420 is used to measure incoming and reflected PPFD around plants and other organisms in outdoor environments, greenhouses, growth chambers, and underwater.

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.

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. Independent Calibration

The SQ-420 is calibrated independently for sunlight and electric light to improve measurement accuracy.

The light source calibration can be selected in the settings menu of the Apogee software.

Specifications Resolution: 0.1 µmol m-2 s-1

Calibration Factor: custom for each sensor and stored in the firmware

Calibration Uncertainty: ± 5 %

Measurement Repeatability: less than 1 %

Non-stability (Long-term Drift): less than 2 % per year

Non-linearity: less than 1% (up to 3000 µmol m-2 s-1)

Response Time: software updates every second

Field of View: 180°

Spectral Range: 410 nm to 655 nm (wavelengths where response is greater than 50% of maximum)

Directional (Cosine) Response: ± 5 % at 75° zenith angle

Temperature Response: 0.06 ± 0.06 % per C

Operating Environment: -40 to 70 C, 0 to 100% relative humidity;

Can be submerged in water up to depths of 30 m

Dimensions: 2.4 cm diameter and 2.8 cm height

Mass: sensor head weighs 90 g

USB Cable: 4.6 m (15 ft)

Current Draw (when Logging): 5.1 mA

Warranty: 4 years