EKO INSTRUMENTS CO., LTD. MS-56 Pyrheliometer Manual Ver.5
Pg. 14
5 - 3 . O p e r a t i o n
After installing and connecting MS-56 to the measurement device, MS-56 can be operated and is ready to
collect solar radiation data.
It is recommended to use the window heater to prevent dew deposition at the Quartz window. Turn on the
heater at least 30 minutes before sunrise. After sun rise, the window heater might be switched off to save
energy.
1. Calculate Direct Normal Incidence Solar Irradiance
The direct normal incidence solar irradiance is calculated from the measured output voltage according to the
following linear expression.
I
[W/m
2
]:
Direct Normal Incidence solar irradiance
E
[µV]:
Output voltage of the sensor
S [µV/W
･
m
-2
]:
Sensitivity (Indicated on the calibration certificate)
2. Calculate Direct Horizontal Incidence Solar Irradiance
The direct horizontal incidence solar irradiance is calculated from the measured output voltage according to
the following linear expression.
θ
[°]:
Solar Elevation Angle
3. Calculate Detector Temperature
When a thermistor temperature sensor
(44031 10kΩ) is used, the detector temperature T[
℃
] can be
converted from resistance R[
Ω] by using the following formula. The temperature conversion table is also
shown in Appendix A-2.
[Thermistor (44031
10kΩ)]
α
= 1.0295
・
10
-3
β
= 2.3910
・
10
-4
γ
= 1.5680
・
10
-7
When using a platinum resistance temperature sensor (Pt100, Class A), see the temperature conversion table
shown in Appendix A-3.
