Menu Close

SQ-500-SS: Full-Spectrum Quantum Sensor

Make: Apogee                                      Model: SQ-500-SS
✅ It measures incident PPFD on plant canopies in outdoor environments or in greenhouses and growth chambers and reflected or under-canopy (transmitted) PPFD measurement in the same environments
✅ Measurand: Photosynthetic Photon Flux Density(PPFD)
✅ Sensor Type: Blue-enhanced silicon photodiode
✅ Signal Output: Analog (0 to 40 mV)
✅ Supplied With: 5 m Cable, Factory test/ Calibration Certificates.

SQ-500-SS: Full-Spectrum Quantum Sensor:

The SQ-500 is a self-powered, analog, full-spectrum quantum sensor with a 0 to 40 mV output. The sensor incorporates a blue-enhanced silicon photodiode and custom optical filters with a rugged, self-cleaning sensor housing design, an anodized aluminum body with an acrylic diffuser, and high-quality cable terminating in pre-tinned pigtail leads for easy connection to dataloggers and controllers.

Typical applications include PPFD measurements over plant canopies in outdoor environments, greenhouses, and growth chambers, and reflected or under-canopy (transmitted) PPFD measurements in the same environments. Quantum sensors are also used to measure PAR and PPFD in aquatic environments, including saltwater aquariums where corals are grown. To facilitate sensor removal and replacement for maintenance and calibration, the sensor includes an IP68 marine-grade stainless-steel cable connector 30 cm from the head.

The analog version of this sensor (SQ-500) comes with the inline cable connector placed 30 cm from the sensor head for either standard use as a long-cable pigtail sensor, or for use with our microCache Bluetooth Micro Logger by unscrewing the connector, discarding the long section of cable and then screwing the sensor to the mating connector on the microCache.

Apogee Instruments SQ-500 series quantum sensors consist of a cast acrylic diffuser (filter), interference filter,
photodiode, and signal processing circuitry mounted in an anodized aluminum housing, and a cable to connect the
sensor to a measurement device. SQ-500 series quantum sensors are designed for continuous PPFD measurement
in indoor or outdoor environments. The SQ-500 model quantum sensor outputs a voltage that is directly
proportional to PPFD. The voltage output by the sensor is directly proportional to radiation incident on a planar
surface (does not have to be horizontal), where the radiation emanates from all angles of a hemisphere.

Application and features of SQ-500-SS: Full-Spectrum Quantum Sensor:



✅ Applied to plant photosynthesis research, vegetation index research, etc.
✅ Greenhouse Monitoring
✅ Agricultural production
✅ Accurate, Stable Measurements
✅ Typical PPFD Measurement
✅ Calibration Traceability




Weight (Mass)

100 g


24 mm diameter, 37 mm height

Measurement Range

0 to 4000 µmol mˉ² sˉ¹


0.01 mV per µmol mˉ² sˉ¹

Operating Temperature

-40 to +70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m

Temperature Response

-0.11 ± 0.04 % per C

Cable Length

5 m of shielded, twisted-pair wire with TPR jacket (high water resistance, high UV stability, flexibility in cold conditions)

Field Of View


Protection Level



There are no reviews yet.

Be the first to review “SQ-500-SS: Full-Spectrum Quantum Sensor”

Your email address will not be published. Required fields are marked *

Quote SQ-500-SS: Full-Spectrum Quantum Sensor