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Enabling better global research outcomes in soil, plant & environmental monitoring.

SU-100 Ultraviolet Sensor

Apogee UV sensors incorporate a photodiode that measures combined UVA and UVB radiation. The sensor housing design features a fully potted, domed-shaped head making the sensor fully weatherproof and self-cleaning.

Sensitivity: 0.2 mV per µmol m-2 s-1, 0.58 mV per W m-2
Calibration Factor: 5.0 µmol m-2 s-1 per mV (reciprocal of sensitivity), 1.65 W m-2 per mV (reciprocal of sensitivity)
Calibration Uncertainty: ± 10%
Measurement Repeatability: ± 1%
Non-stability (Long-term Drift): < 3% per year
Non-linearity: < 1% (up to 300 µmol m-2 s-1)
Response Time: < 1 ms
Field of View: 180°
Spectral Range: 250 nm to 400 nm
Directional (Cosine) Response: ± 10% at 75° zenith angle
Temperature Response: approximately 0.1% per °C
Operating Environment: -40 to 70°C, 0 to 100% relative humidity
Dimensions: 2.4 cm diameter and 2.8 cm height
Mass: 75g (with 5m of lead wire)
Cable: 5m of shielded, twisted-pair wire. Santoprene rubber jacket
Warranty: 4 years

INTRODUCTION

Ultraviolet (UV) radiation constitutes a portion of the electromagnetic spectrum from 100 to 400 nm, and is further subdivided into three wavelength ranges: UV – A (315 to 400 nm), UV – B (280 to 315 nm) and UV – C (100 to 280 nm). Much of the UV – B and all of the UV – C wavelengths from the sun are absorbed by the Earth’s atmosphere . There are also many artificial UV light sources available that output a selective wavelength range or offer a broadband UV radiation source.

Most UV sensors designed for sunlight measurements are sensitive to UV radiation in the UV – A and UV – B ranges. Apogee Instruments SU-100 UV sensors detect UV radiation from 250 to 400 nm and are calibrated in photon flux units of micromoles per square meter per second (µmol m-2 s-1). The output can also be expressed in energy flux units of watts per square meter (W m – 2, equal to Joules per second per square meter). Typical applications of UV sensors include incoming UV radiation measurement in outdoor environments or in laboratory use with artificial light sources (e.g. germicidal lamps).

Apogee Instruments SU-100 UV sensors consist of a photodiode and signal processing circuitry mounted in an anodised aluminium housing, and a cable to connect the sensor to a measurement device. Sensors are potted solid with no internal air space, and are designed for continuous UV radiation measurement in indoor or outdoor environments. The SU-100 outputs an analogue voltage that is directly proportional to UV radiation incident on a planar surface (does not have to be horizontal), where the radiation emanates from all angles of a hemisphere.