INFORMATION
Description
Measure photosynthetically active radiation, PAR, in µmol m-2 s-1
Apogee Instruments' quantum sensors provide accurate and cost-effective measurement of photosynthetically active radiation (PAR) from all light sources used to grow plants.
Apogee Instruments SQ series quantum sensors consist of a cast acrylic diffuser (filter), photodiode, and signal processing circuitry mounted in an anodized aluminium housing, and a cable to connect the sensor to a measurement device. Sensors are potted solid with no internal air space. SQ-500 series quantum sensors are designed for continuous PPFD measurement in indoor and outdoor environments.
Features
Spectral Response
The full-spectrum quantum sensor has a spectral range of 389 to 692 nm ± 5 nm. The improved spectral response increases the accuracy of LED measurements.
The spectral responses can be seen in the graph below:
Accurate, Stable Measurements
Sensors are cosine-corrected to maintain their accuracy when radiation comes from low zenith angles. The sensors measure PPFD with a cosine response accurate within ± 5 % at 75° zenith angle. Long-term non-stability determined from multiple replicate quantum sensors in accelerated aging test and field conditions is less than 2 % per year.
Rugged, Self-cleaning Housing
Patented domed shaped sensor head (diffuser and body) facilitates runoff of dew and rain to keep the sensor clean and minimize errors caused by dust blocking the radiation path. Sensors are housed in a rugged anodized aluminum body and electronics are fully potted.
Ideal for Measurements in Air and Underwater
Apogee quantum sensor are calibrated to make absolute PPFD measurements in air. The waterproof sensors can be used to make absolute PPFD measurements underwater by applying an immersion effect correction factor, the SQ-420, SQ-520, MQ-210, and MQ-510 already apply the correction factor.
Calibration
To ensure accuracy each sensor is carefully calibrated in controlled conditions and traceable to NIST reference standards. The full-spectrum sensors are pre-calibrated for all light sources.
Mounting
The AL-120 Solar Mounting Bracket with Leveling Plate facilitates mounting the sensor to a mast or pipe. The AL-100 Solar Sensor Leveling Plate is designed to level the sensor while sitting on a flat surface or mounting to a surface.
Output Options
Available in multiple analog output options including 0 to 40 mV, 0 to 2.5 V, and 0 to 5 V. Additionally, a digital "smart" sensor that uses USB communication and custom software to interface directly to a computer is available. Sensors are also available attached to a hand-held meter with digital readout.
High Quality Cable
Pigtail-lead sensors feature an IP68, marine-grade stainless-steel cable connector approximately 30 cm from the head to simplify sensor removal for maintenance and recalibration. Cable is shielded-twisted pair wire with a TPR jacket for high water resistance, UV stability, and flexibility in cold conditions.
Warranty
All Apogee products are backed by an industry-leading 4-year warranty.
Applications
- PPFD measurements over plant canopies in outdoor environments, greenhouses, and growth chambers.
- Reflected or under-canopy (transmitted) PPFD measurements in outdoor environments, greenhouses, and growth chambers.
Helpful tips
PAR is often expressed as photosynthetic photon flux density (PPFD): photon flux in units of micromoles per square meter per second (µmol m-2 s-1, equal to microEinsteins per square meter per second) summed from 400 to 700 nm (total number of photons from 400 to 700 nm). While Einsteins and micromoles are equal (one Einstein = one mole of photons), the Einstein is not an SI unit, so expressing PPFD as µmol m-2 s-1 is preferred.
Sensors that measure PPFD are often called quantum sensors due to the quantized nature of radiation. A quantum refers to the minimum quantity of radiation, one photon, involved in physical interactions (e.g., absorption by photosynthetic pigments). In other words, one photon is a single quantum of radiation.
Green Houston is an official distributor for all Apogee instruments in Africa, imported directly from the USA.
Please contact office@greenhouston.co.za for all Apogee sensors and variants.
Please note: Apogee products are imported from the USA and due to the fluctuating exchange rate, prices are not fixed and may be subject to change. Requesting a quote before placing an order is highly recommended.
Educational videos
Why do I need a PAR-Quantum Meter?
In-depth Look at PAR-Quantum Meters