Specification Sheet

ManualsBrandsFGI ManualsIndustrial & ScientificApogee Instruments SDI-12 Digital Output Quantum Sensor

Dimensions

Features

APOGEE QUANTUM SENSORS |

SQ-421-SS & SQ-422-SS

Mulple Output Opons

• SDI-12

• ModBus

• 0 to 800 mV

• 0 to 2.5 V

• 0 to 5 V

• 4 to 20 mA

• USB

Accurate, Stable Measurements

Cosine-corrected with direconal errors

less than ± 5 % at a solar zenith angle of

75°. Long-term non-stability less than 2 %

per year.

Unique Design

Cost-eecve, original quantum sensors

work well for broadband radiaon sources

(sun, high-pressure sodium, metal halide,

cool white uorescent lamps). The

patented, dome-shaped aluminum head is

cosine-corrected, self-cleaning, and fully-

poed for a waterproof design.

Typical PPFD Measurement

Applicaons

• Incoming and reected PPFD over and

under plant canopies in greenhouses, in

elds, and in growth chambers

• Aquac environments including salt

water aquariums and freshwater lakes and

streams

Calibraon Traceability

Apogee SQ sensors are calibrated through side-by-side comparison

to the mean of (4) Apogee model SQ-110 or SQ-120 transfer

standard sensors under high output T5 cool white uorescent

lamps. The transfer standard sensors are calibrated through

side-by-side comparison to the mean of at least (3) LI-COR model

LI-190R reference quantum sensors under high output T5 cool

white uorescent lamps. The reference sensors are recalibrated

on a biannual schedule with a LI-COR model 1800-02 and quartz

halogen lamp that are traceable to the Naonal Instute of

Standards and Technology (NIST).

Measure photosynthecally acve

radiaon (PAR) in μmol m⁻² s⁻¹

SQ-311

Summary of content (2 pages)

PAGE 1
APOGEE QUANTUM SENSORS | SQ-421-SS & SQ-422-SS Measure photosynthetically active radiation (PAR) in μmol m⁻² s⁻¹ SQ-311 Features Multiple Output Options • SDI-12 • ModBus • 0 to 800 mV • 0 to 2.5 V • 0 to 5 V • 4 to 20 mA • USB Accurate, Stable Measurements Cosine-corrected with directional errors less than ± 5 % at a solar zenith angle of 75°. Long-term non-stability less than 2 % per year.
PAGE 2
Cosine Response Mean cosine response of (7) Apogee SQ-500 quantum sensors. Cosine response measurements were made on the rooftop of the Apogee building in Logan, UT. Cosine response was calculated as the relative difference of SQ-500 quantum sensors from the mean of replicate reference quantum sensors (LI-COR models LI-190 and LI-190R, Kipp & Zonen model PQS 1). The red data are AM measurements; the blue data are PM measurements.