Loading... Please wait...

SQ-326: Electric Calibration Line Quantum with 6 Sensors

Click images for larger view
  • Apogee Instruments SQ-326 Electric Calibration Line Quantum Sensor with 6 sensors.
  • Line quantum sensor-Sensor close up

Product Description

Apogee line quantum sensors measure a spatial average of  PAR (Photosynthetically Active Radiation). The SQ-326 has a sensor bar with 6 sensors and is self-powered with a 0 to 800 mV output. The sensor is calibrated for use in sunlight. The sensor housing design features an integrated bubble level and is fully potted making the sensor weatherproof. Typical applications include PPFD (Photosynthetic Photon Flux Density) measurement 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/PPFD in aquatic environments, including salt water aquariums where corals are grown.


Specification Sheets
Technical Information
Sample Datalogger
Technical Drawings
Technical Information


Case Studies

PAR Measurements Characterize Tree Coverages

PAR Measurements Characterize Tree Coverages
Using line quantum meter to study the percent of PAR (under canopy/open sky) and its relation to survival and initial growth of native forest species.
Read More >


Line Quantum in Greenhouse

Controlling Flowering of Orchids in Greenhouse
Line quantum sensor used to measure PPFD and daily light integral, while experimenting with temperature to control flowering.
Read More >


Product Videos

How to Choose an Oxygen Sensor for your Application (05:20)
What oxygen sensor do you need for your application? This how-to-video covers Apogee Instruments’ four different analog oxygen sensors and the applications they are best suited for, including measuring percent oxygen in air and soil. VIDEO CONTENT The video covers seven topics that should be looked at when trying to decide which oxygen sensor is right for your application. 00:21 1. What do Apogee SO Oxygen Sensors measure? Apogee Instruments oxygen sensors measure gaseous oxygen. This can be in soil, air, or in a chamber. It is important to note they do not measure dissolved oxygen or oxygen in liquids. 00:43 2. What is the difference between the SO-100 and SO-200 series? The simple answer is the difference between the SO-100 and SO-200 series is the signal size versus response time. The sensitivity for the 100 series is about 2.6 mV per percent O2 and the 200 series is about 0.6 mV per percent O2. The 100 series have a response time of 60 seconds and the 200 series is 14 seconds. Larger signal size equals longer response time. 02:15 3. Do I need to measure the sensor body temperature? This depends on your application temperature. 02:57 4. Should I choose a thermistor or thermocouple model? It really is up to your personal preference or whichever you datalogger needs. If you don’t have a requirement or preference it is our recommendation to go with the thermistor. We believe they make better and more accurate measurements. 03:20 5. Does the heater have to be powered to get the oxygen reading? You can read oxygen without the heater being plugged in, however, if you’re anywhere where water can condense on the membrane then you will want the heater plugged in so it is always evaporating and you are getting accurate readings. 03:43 6. How do I measure the oxygen? What is the wiring diagram? The wiring diagram for both SO-100 and SO-200 series is covered. 04:31 7. Do I need an accessory head? If you are in a chamber or a room you may not need an accessory head. If you’re in soil, media, dirt, or the ground we recommend the AO-001 diffusion head, and if you’re in a lab where you want flow through tubes connected we recommend the AO-002 flow through head. More information at https://www.apogeeinstruments.com/oxygensensor/. ------ More tech support tutorial videos can be found at https://www.youtube.com/playlist?list=PLOTpNTsJcpqcflPlQH_b8c_qO9bv2Jocp. ------- Follow us to see all the cool places our sensors are used, get notices for free classes and how to videos, and product announcements! -Blog http://blog.apogeeinstruments.com/ -Facebook https://www.facebook.com/ApogeeInstruments/ -Twitter https://www.twitter.com/ApogeeInst/ -LinkedIn https://www.linkedin.com/company/1084851 ------ BUY APOGEE OXYGEN SENSORS https://www.apogeeinstruments.com/oxygensensor/
  • How to Choose ...
    What oxygen sensor do you need for your application? This how-...
  • Why do I need ...
    Dr. Bruce Bugbee, of Apogee Instruments, explains the differen...
  • Quantum Par Me...
    Apogee Instruments quantum sensors measure photosynthetically ...


Power Supply
0.2 mV per µmol m-2 s-1
Calibration Factor
5.0 µmol m-2 s-1 per mV (reciprocal of sensitivity)
Calibration Uncertainty
± 5%
Calibrated Output Range
0 to 800 mV
Measurement Repeatability
Less than 0.5%
Non-stability (Long-term Drift)
Less than 2 % per year
Less than 1 % (up to 4000 µmol m-2 s-1; maximum PPFD measurement is 2500 µmol m-2 s-1)
Response Time
Less than 1 ms
Field of View
Spectral Range
410 nm to 655 nm
Spectral Selectivity
Less than 10 % from 469 to 653 nm
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
500 mm length, 15 mm width, 15 mm height
275 g (with 5 m of lead wire)
5 m of shielded, twisted-pair wire. Santoprene rubber jacket (high water resistance, high UV stability, flexibility in cold conditions). Pigtail lead wires
4 years against defects in materials and workmanship

Find Similar Products by Category

You Recently Viewed...