INDEX
Long-Term Irradiance Stability under 24-Hour Continuous Irradiation
This page presents the results of irradiance stability measurements conducted under 24-hour continuous irradiation using SAN-EI single-lamp Solar Simulators.
24-hour measurement (24H measurement)
The purpose of this measurement is to visualize the variation characteristics of the reference irradiance (1 SUN) during long-term operation and to quantitatively show the fluctuation range and temporal variation behavior.
The measurement
The measurement is evaluated using the following two tests in order to observe the long-term behavior of irradiance and to confirm the influence of the irradiance sensor temperature.
24-hour measurement (24H measurement)
This measurement evaluates the temporal variation characteristics of irradiance during 24 hours of continuous irradiation and assesses the fluctuation range and long-term drift during extended operation.
6-hour measurement (6H measurement)
This measurement observes the irradiance behavior after system start-up and evaluates the relationship between pyranometer temperature and surrounding temperature.
Measurement Concept
In long-duration irradiance measurements, the measured value can change not only due to the light source but also due to the temperature characteristics of the irradiance sensor.
Therefore, this measurement distinguishes between the stability of the light source and the influence of the sensor temperature.
A 24-hour continuous irradiation test is conducted to observe the long-term behavior of irradiance.
In parallel, a 6-hour measurement with intermittent exposure of the sensor is performed to confirm the influence of sensor temperature rise.
To evaluate operational stability, the stability time is defined as the time when irradiance first enters the ±1% band of the average irradiance of a visually determined stable region and does not leave this band thereafter.
All statistical values are calculated using the data within this stable region.
The measurement results for each model are published as individual pages.
Target Models
Small size
20×20－50×50 mm
Medium size
70×70－200×200 mm
Large size
250×250－400×400 mm
Each model page
- Warm-up time
- Average irradiance
- Maximum value
- Minimum value
- Variation range
- Temporal variation rate
- Long-term drift
- Comparison of main and sub pyranometers
- Relationship between irradiance and temperature