The MP-200 has a sensor separated from the handheld unit by a 2m long cable. integrated into the top of the housing while the handheld meter displays and stores measurements. The MP-100 is ideally suited for quick and convenient spot measurements of global solar radiation in the range between 380 and 1120nm.
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.
Pyranometers are sensors that measure global shortwave radiation. Apogee MP series solar radiation meters incorporate 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 Standardisation (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 MP series solar radiation meters consist of a handheld meter and a dedicated pyranometer that is integrated into the top of the meter housing (MP-100) or connected by cable to an anodised aluminium housing (MP-200). Integrated and separate sensors consist of a cast acrylic diffuser (filter), photodiode, and are potted solid with no internal air space. MP series meters provide a real-time irradiance reading on the LCD display that determines the radiation incident on a planar surface (does not have to be horizontal), where the radiation emanates from all angles of a hemisphere. MP series meters include manual and automatic data logging features for making spot – check measurements or calculating daily solar insolation.
|Calibration Uncertainty:||± 5%|
|Measurement Repeatability:||< 1%|
|Non-stability (Long-term Drift):||< 2% per year|
|Non-linearity:||< 1% (up to 1999 W m-2)|
|Response Time:||< 1 ms|
|Field of View:||180°|
|Spectral Range:||380 to 1120 nm (wavelengths where response is 10 % of maximum)|
|Directional (Cosine) Response:||± 5 % at 75° zenith angle|
|Temperature Response:||0.04 ± 0.04% per °C|
|Operating Environment:||0 to 50°C|
|Dimensions:||2.4 cm diameter and 2.8 cm height|