The SQ-500 is a self-powered, analog full-spectrum quantum sensor with a 0 to 40 mV output. The sensor incorporates an enhanced silicon photodiode and custom optical filters with a rugged, self-cleaning.
DESCRIPTION SQ-500-SS
The SQ-500 is a self-powered, analog full-spectrum quantum sensor with a 0 to 40 mV output. The sensor incorporates an enhanced silicon photodiode and custom optical filters with a rugged, self-cleaning sensor housing design, anodized aluminum body with acrylic diffuser, and an inline cable connector placed 30 cm from the sensor head for either standard use as a long-cable pigtail sensor, or for use with 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. Typical applications include PPFD 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. Sensor includes IP68 marine-grade stainless-steel cable connector 30 cm from head to simplify sensor removal and replacement for maintenance and recalibration.
How is the SQ-500 different from previous Apogee quantum sensors?
The SQ-500 is a full spectrum quantum sensor with a spectral range of 389 to 692 nm ± 5 nm, which can be seen in the graph below. This improved spectral response increases the accuracy of LED measurements.
Where is the SQ-500 used?
The SQ-500 is used to measure incoming PPFD measurements in outdoor environments, greenhouses, growth chambers, and aquariums.
SPECIFICATIONS SQ-500-SS
| Power Supply |
Self-powered |
| Output (Sensitivity) |
0.01 mV per µmol mˉ² sˉ¹ |
| Calibration Factor (Reciprocal of Sensitivty) |
100 µmol mˉ² sˉ¹ per mV |
| Calibration Uncertainty |
± 5 % |
| Calibrated Output Range |
0 to 40 mV |
| Measurement Range |
0 to 4000 µmol mˉ² sˉ¹ |
| Measurement Repeatability |
Less than 0.5 % |
| Long-term Drift |
Less than 2 % per year |
| Non-linearity |
Less than 1 % (up to 4000 µmol mˉ² sˉ¹) |
| Response Time |
Less than 1 ms |
| Field of View |
180˚ |
| Spectral Range |
389 to 692 nm ± 5 nm (wavelegths where response is greater than 50 % of maximum) |
| Spectral Selectivity |
Less than 10 % from 412 to 682 nm ± 5 nm |
| Directional (Cosine) Response |
± 5 % at 75˚ zenith angle |
| Azimuth Error |
Less than 0.5 % |
| Tilt Error |
Less than 0.5 % |
| Temperature Response |
-0.11 ± 0.04 % per C |
| Uncertainty in Daily Total |
Less than 5 % |
| Detector |
Blue-enhanced silicon photodiode |
| Housing |
Anodized aluminum body with acrylic diffuser |
| IP Rating |
IP68 |
| Operating Environment |
-40 to 70 C; 0 to 100 % relative humidity; can be submerged in water up to depths of 30 m |
| Dimensions |
24 mm diameter, 37 mm height |
| Mass |
100 g (with 5 m of lead wire) |
| Cable |
5 m of shielded, twisted-pair wire with TPR jacket (high water resistance, high UV stability, flexibility in cold conditions) |
| Warranty |
4 years against defects in materials and workmanship |
| Manufactured |
Made in the USA |