Description

LP PYRHE 16 : Pyrheliometer ( First Class According to ISO 9060 Classification)

The LP PYRHE 16 Pyrheliometer (First Class Pyrheliometer according to ISO 9060 classification) is an instrument for direct measurement of solar irradiance (Watt/m2). The receiving surface must be positioned (via a solar tracker or else) perpendicularly to sun’s rays. The use of apposite diaphragms allows only direct light to hit the surface of the sensor. According to WMO (Seventh edition 2008) and ISO 9069 regulations, the Pyrheliometer has a field of view of 5°.

Working Principle

The LP PYRHE 16 Pyrheliometer is based on a new passive thermopile sensor. The sensitive surface of the thermopile is coated with a matt black paint, which makes the instrument not selective to the different wave lengths. The spectral range of the Pyrheliometer is determined by the transmission of the quartz window, whose function is to protect the sensor from dust and water. A special quartz allows to perform a 200nm-4000nm non-selective measurement.

The adopted sensor allows to have a response time lower than the requirements of the ISO9060 for the classification of first class Pyrheliometers (the response time is under 9 seconds while the standard requires a response time lower than 20 seconds). Radiant energy is absorbed by the blackened surface of the thermopile, thus creating a difference in temperature between the hot junction and the body of the pyrheliometer, which in this case acts as a cold junction. Through the Seebeck effect, the difference in temperature between hot and cold junction is converted into a Difference of Potential.

LP PYRHE 16 should be mounted in an easily reachable place to allow periodic cleaning of the quartz window and maintenance. At the same time you should avoid buildings, trees or obstructions of any kind intercepting the path of the sun during the day, all year round. For the automatic tracking of the pyrheliometer.

                                                                     Technical Specification

ISO 9060 Classification :  First class

Detector  type : Based on a passive thermopile sensor

Measuring range : 0 to 2000 W/m2

Spectral range : 200 nm to 4000 nm

Typical sensitivity : 10 mV/( W/m2)

Operating temperature :  - 40 0C to 80 0C

Operating humidity : 0 to 100%

Response time (95%) : < 9 sec.

Field of View : 5° (slope 1°) 

Zero Off-set : Response to temperature change of 5K/h : <± 3 W/m2

Long term instability (over 1 year) : <± 1%

Non linearity : <± 0.5%

Response depending on temperature : <± 2%

Response depending on Tilt : <± 0.5%

Spectral selectivity : <± 1%

Impedance : 5Ω to  50Ω

Cable : 10 meter cable

Weight : 1.5 Kg