GHM Delta OHM LPPIRG01, Operating Manual, Page: 3 / 26

LPPIRG01
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V2.1
1 INTRODUCTION
LPPIRG01 pyrgeometer measures the far infrared radiation (FIR). The measures are
referred to radiations with wavelength greater than 4.5 µm.
The far infrared radiation derives from the measure of the thermopile output signal and
from the knowledge of the instrument temperature. The temperature is measured with
a 10 k Ω NTC inserted in the body of the pyrgeometer.
The pyrgeometer can be used also for energy balance studies. In this case, besides
another pyrgeometer which measures infrared radiation upwards, it is necessary an
albedometer (LPPYRA05, LPPYRA06 or LPPYRA11) for measuring the short wavelengths
radiation (<3 µm).
The pyrgeometer is available in the following versions:
•
LPPIRG01: Passive
•
LPPIRG01S: With RS485 Modbus-RTU output.
The pyrgeometer is supplied factory calibrated and with a calibration report. The cali-
bration is carried out outdoors, for comparison with a reference standard pyrgeometer
calibrated at WRC (World Radiation Center). The two instruments are kept outdoors for
at least one night in the presence of clear sky. The data acquired by a data logger are
then processed to obtain the calibration factor.