The PMA2145 is an ISO-classified first class pyranometer. It is based on the thermopile technology assuring very broad spectral sensitivity with exceptional flatness and very good long term stability. The PMA2145 features a sixty-four thermocouple junction sensing element. The sensing element is coated with a highly stable carbon based non-organic coating, which delivers excellent spectral absorption and long term stability characteristics. The sensing element is housed under two concentric fitting Schott K5 glass domes.
 

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> With Sunscreen

>Detectors need to be used with a Radiometer

> Analog version of this detector can be used with any 0 to 5 VDC or 4 to 20mA recording device

FEATURES

• Very wide and flat spectral response
• Excellent long term stability
• Cosine corrected
• NIST traceable calibration
• ISO classified
• Low cost
• Weatherproof
• Bubble level

APPLICATIONS

• Meteorology
• Agriculture
• Solar power research and testing
• Heating and air conditioning
• Lighting
• Physics and optical laboratories

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.

Specifications

• Spectral response 310-2800nm FWHM Figure 1
• Range 2000 [W/m²], 200 [mW/cm²]
• Response time 18 seconds (95%)
• Sensitivity change/year <1%
• Non-linearity <1.0% (1000W/m²)
• Temperature dependence  <2% (-10 to 40°C)
• Angular response 1% for angles <70°
• Zero offsets <15W/m² @200 W/m² thermal radiation
• Display resolution 1[W/m²], 0.1[mW/cm²]
• Operating environment -40 to 175 °F (-40 to +80 °C), outdoors
• Temperature coefficient <5% (-10 to +40°C)
• Cable 30ft, 9m
• Diameter with Sun Screen 2.375" (60.3 mm)
• Diameter Without Sun Screen 3.08” (78.11mm)
• Height 3.31" (84.0mm)
• Weight 11oz (0.31kgram)

Analog versions of this detector are available See PMA1145

Analog connection: Two wire, stripped and tinned, 0 to 50 millivolt input.

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