LPPYRA10
- 15 -
V2.6
5
MEASUREMENT IN THE MODELS WITH ANALOG OUTPUT
Below are the ways to calculate the global irradiance in the models with analog output
LPPYRA10, LPPYRA10AC[S][4] and LPPYRA10AV[4].
5.1
LPPYRA10
Each pyranometer is distinguished by its own sensitivity (or calibration factor)
S
ex-
pressed in µV/(Wm
-2
) and shown in the label on the pyranometer (and in the calibra-
tion report).
The irradiance
E
e
is obtained by measuring with a multimeter the difference of potential
DDP
at the ends of the sensor and applying the following formula:
E
e
=
DDP
/
S
where:
E
e
is the irradiance expressed in W/m
2
;
DDP
is the difference of potential expressed in
µ
V measured by the multimeter;
S
is the sensitivity of the pyranometer expressed in µV/(Wm
-2
).
5.2
LPPYRA10AC[S][4]
The 4…20 mA output signal corresponds to 0…2000 W/m
2
(LPPYRA10AC[S]) or 0…4000
W/m
2
(LPPYRA10AC[S]4) irradiance range.
The irradiance
E
e
is obtained by measuring with a multimeter the current
I
out
absorbed
by the sensor and applying the following formula:
E
e
= 125
•
(
I
out
- 4
)
if f.s.= 2000 W/m
2
E
e
= 250
•
(
I
out
- 4
)
if f.s.= 4000 W/m
2
where:
E
e
is the irradiance expressed in W/m
2
;
I
out
is the current expressed in mA absorbed by the pyranometer.
5.3
LPPYRA10AV[4]
The output signal (0…1 V, 0…5 V or 0…10 V depending on the version) corresponds to
0…2000 W/m
2
(LPPYRA10AV) or 0…4000 W/m
2
(LPPYRA10AV4) irradiance range.
The irradiance
E
e
is obtained by measuring with a multimeter the output voltage
V
out
of
the sensor and applying the following formula:
E
e
= 2000
•
V
out
for the version 0…1 V with f.s.= 2000 W/m
2
E
e
= 4000
•
V
out
for the version 0…1 V with f.s.= 4000 W/m
2
E
e
= 400
•
V
out
for the version 0…5 V with f.s.= 2000 W/m
2
E
e
= 800
•
V
out
for the version 0…5 V with f.s.= 4000 W/m
2
E
e
= 200
•
V
out
for the version 0…10 V with f.s.= 2000 W/m
2
E
e
= 400
•
V
out
for the version 0…10 V with f.s.= 4000 W/m
2
where:
E
e
is the irradiance expressed in W/m
2
;
V
out
is the output voltage expressed in V measured by the multimeter.
