EKO INSTRUMENTS CO., LTD. - Pyranometer MS-60/60S - Instruction Manual Ver. 4
Pg. 18
5 - 3 . M e a s u r i n g S o l a r I r r a d i a n c e
1. Solar Irradiance Measurement
1) In case of MS-60 [mV output]:
Global solar Irradiance [W/m
2
] can be determined by measuring the output voltage [mV] divided by the
individual sensor sensitivity [μV/W
・
m
-2
]. The output voltage is measured by a measuring device such as
voltmeter or data logger. If solar irradiance is measured continuously, it is recommended to use data
logger which has sufficient recording capacity and calculation function.
Procedure for solar irradiance measurement is described below:
a. Configuration with a Data logger
If the measurement range can be selected on the data acquisition system, select the measurement
range, which can accurately measure the signal over a range of 0 to 20mV. The solar irradiance
assumed that it does not exceed 1,400W/m
2
in both horizontal and tilted measurement positions.
The maximum output voltage can be calculated by multiplying the maximum solar irradiance with the
calibration factor [e.g. when the sensitivity of the MS-60
pyranometer is about 10μV/W
・
m
-2
or
0.010mV/W
・
m
-2
, the maximum output voltage is about 1,400W/m
2
times 0.010mV/W
・
m
-2
= 14mV].
b. Calculate the Solar Irradiance [W/m
2
].
The solar irradiance in Watts per meter squared [W/m
2
] is obtained when the output voltage
E
[μV] is
divided by the sensitivity of the pyranometer
S
[μV/W
・
m
-2
]. This calculation is expressed by the
following formula:
I
[W/m
2
] =
*The sensitivity
S
for the pyranometer is stated on the calibration certificate and the product label.
2) In Case of MS-60S [4-20mA Output]
a.
Configure the Measurement Range
If the measurement range can be selected on the data acquisition system, select the measurement
range which can accurately measure the signal within a range of 4 to 20mA. The global
broad-band solar irradiance assumed that it does not exceed 1,400W/m
2
in both horizontal and
tilted measurement positions.
When this is converted into MS-60S output, the result will be 20mA
[default].The output for the MS-60S [4-20mA output] is set to be 1,600W/ m2 at 20mA.
b.
Calculate the Solar Irradiance [W/m
2
]
When the solar irradiance current value is
A
[mA], the solar irradiance
I
[W/m
2
] can be determined
by the following formula:
I
[W/m
2
] =
Sa
=0.01 (default setting)
E
[
μ
V]
S
[
μV/W
･
m
-2
]
A
[mA] - 4
Sa
[mA/W
･
m
-2
]