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

SP-110 Pyranometer

The SP-110 is a low cost yet highly accurate self-powered sensor with a millivolt output and exhibits excellent cosine response. The SP-110 is the first choice sensor for scientists who want to measure global solar radiation.

The SP-110 incorporates a silicon-cell photodiode that measures total shortwave radiation with a sensor housing design that features a fully potted, domed-shaped head making the sensor fully weatherproof and self-cleaning.

The SP-110 measures radiation between 380 and 1120nm. This shortwave radiation is an important component in determining evapotranspiration rates, energy balance, net radiation as well as monitoring solar power panels.

The SP-110 is ideally supported by the LSM3 Light Sensor Meter for Pyranometers for data logging and long term monitoring.

Sensitivity: 0.20 mV per W m-2
Calibration Factor: 5.0 W m-2 per mV (reciprocal of sensitivity)
Calibration Uncertainty: ± 5%
Measurement Repeatability: < 1%
Non-stability (Long-term Drift): < 2% per year
Non-linearity: < 1% (up to 1750 W m-2)
Response Time: < 1 ms
Field of View: 180°
Spectral Range: 360 nm to 1120 nm (wavelengths where response is 10 % of maximum)
Directional (Cosine) Response: ± 1% at 45° zenith angle
± 5% at 75° zenith angle
Temperature Response: -0.04 ± 0.04% per °C
Operating Environment: -40 to 70°C, 0 to 100% relative humidity
Dimensions: 2.4 cm diameter and 2.8 cm height
Mass: 90g (with 5m of lead wire)
Power Supply: Self powered
Warranty: 4 years

Solar radiation at Earth’s surface is typically defined as total radiation across a wavelength range of 280 to 4000 nm (shortwave radiation). Total solar radiation, direct beam and diffuse, incident on a horizontal surface is defined as global shortwave radiation, or shortwave irradiance (incident radiant flux), and is expressed in Watts per square meter (Wm-2, equal to Joules per second per square meter). Pyranometers are sensors that measure global shortwave radiation.

Apogee SP series pyranometers are silicon-cell pyranometers, and are only sensitive to a portion of the solar spectrum, approximately 350 – 1100 nm (approximately 80% of total shortwave radiation is within this range). However, silicon-cell pyranometers are calibrated to estimate total shortwave radiation across the entire solar spectrum. Silicon-cell pyranometer specifications compare favourably to specifications for World Meteorological Organisation (WMO) moderate and good quality classifications and specifications for International Organisation of Standardization (ISO) second class and first class classifications, but because of limited spectral sensitivity, they do not meet the spectral specification necessary for WMO or ISO certification.

Typical applications of silicon-cell pyranometers include incoming shortwave radiation measurement in agricultural, ecological, and hydrological weather networks, and solar panel arrays.

Apogee Instruments SP series pyranometers consist of a cast acrylic diffuser (filter), 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 total shortwave radiation measurement on a planar surface in outdoor environments. SP series sensors output an analogue voltage that is directly proportional to total shortwave radiation from the sun. The voltage signal from the sensor is directly proportional to radiation incident on a planar surface (does not have to be horizontal), where the radiation emanates from all angles of a hemisphere.