6
2 Instrument schematic
16131.5’s scientific name is pyranometer. A pyranometer measures the solar radiation received by a
plane surface from a 180° field of view angle. This quantity, expressed in W/m
2
, is called
“hemispherical” solar radiation.
The solar radiation spectrum extends roughly from 285 to 3000 x 10
-9
m. By definition a pyranometer
should cover that spectral range with a spectral selectivity that is as “flat” as possible.
Figure 2.0.1
Overview of 16131.5:
(1) cable
(2) connector
(3) sun screen
(4) bubble level
(5) bubble level window
(6) outer dome
(7) inner dome
(8) thermal sensor with black coating
(9) quick release system of sun
screen
(10) instrument body
(11) levelling feet
The 16131.5 pyranometer series employs a state-of-the-art thermopile sensor with black coated
surface, two domes and an anodised aluminium body.
Version 00.16131.501030 offers irradiance in W/m
2
as a digital output. It must be used in combination
with suitable power supply and a data acquisition system which uses the Modbus communication
protocol over RS-485. In order to reduce the effect of dew deposition and frost on the outer dome
surface, 00.16131.501030 has a built-in heater. The heater is coupled to the sensor body. Heating a
pyrometer can generate additional irradiance offset signals, therefore it is recommended to activate
1
2
3
6
7
8
9
5
4
10
11
