The PMA2141 is an ISO-classified
second class pyranometer. It is based on the thermopile technology assuring very broad
spectral sensitivity with exceptional flatness and very good long term stability. The
sensor is provided to Solar Light Co. by Kipp & Zonen. The precision optical glass dome acts as a filter, with the spectral bandpass that permits the full solar spectrum to pass through to the sensor. The glass dome also protects the sensor from the elements.
The sensor is a high quality blackened thermopile. Heating of the sensor by incoming solar radiation produces a signal in the µvolt range. Each pyranometer has its own calibration factor. Along with the processing algorithm, it is programmed into a memory chip embedded into the sensor. Upon connection to the PMA2100 the processing algorithm is loaded into the meter and the correct reading is immediately displayed on the LCD.
Thermopile type radiation sensors exhibit the widest and most uniform spectral response. It is limited mostly by the spectral transmission of the dome. They are useful to monitor the total radiant power or solar radiation as well as artificial sources. The sensitivity of these types of sensors is somewhat limited and measurements of radiant flux below 10W/m2 are difficult.
Due to almost ideal flatness of the spectral response the pyranometer is often used with a set of low wavelength blocking filters in order to measure radiant power distribution in various bands. The difference between the total power and the power measured with the filter is the radiant power in the band blocked by the filter. A correction that accounts for energy reflected from the filter’s surface is necessary.
In solar radiation studies the diffuse component of the total radiant flux can be measured by using a shadow-band casting a shadow on the pyranometer's entrance. The difference between the total power and the diffuse power measured with shadow-band is the direct component. For better accuracy a correction should be made for the part of diffuse radiation obstructed by the shadow-band itself.
FEATURES
- Very wide and flat spectral response
- Excellent long term stability
- Cosine corrected
- NIST traceable calibration
- ISO classified
- Low cost
- Weatherproof
APPLICATIONS
- Meteorology
- Agriculture
- Solar power research and testing
- Heating and air conditioning
- Lighting
- Physics and optical laboratories
