LPUVA02
- 10 -
V2.0
5
MEASUREMENT
Below are the ways to calculate the irradiance.
5.1
LPUVA02
Each radiometer is distinguished by its own sensitivity (or calibration factor)
S
ex-
pressed in µV/(Wm
-2
) and shown in the label on the radiometer (and in the calibration
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 radiometer expressed in µV/(Wm
-2
).
5.2
LPUVA02AC
The 4…20 mA output signal corresponds to 0…200 W/m
2
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
= 12.5
•
(
I
out
– 4mA
)
where:
E
e
is the irradiance expressed in W/m
2
;
I
out
is the current expressed in mA absorbed by the radiometer.
5.3
LPUVA02AV
The output signal (0…1 V, 0…5 V or 0…10 V depending on the version) corresponds to
0…200 W/m
2
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
= 200
•
V
out
for the version 0…1 V
E
e
= 40
•
V
out
for the version 0…5 V
E
e
= 20
•
V
out
for the version 0…10 V
where:
E
e
is the irradiance expressed in W/m
2
;
V
out
is the output voltage expressed in V measured by the multimeter.
