Solar Simulator: Functions, Types, Grades, Risks and More

Technology is a great creation – we are saying this because there’s something interesting that will make you feel enthusiastic about technology!

Testing for UV radiation has been done since the 19th century when scientists first learned about its effects. Thanks to the latest technological advancements! 

UV testing can be used in multiple ways that we would never have imagined in the 19th century. With a solar simulator and other advanced devices, we can now use this technology to precisely measure the impacts of the sun’s UV rays over multiple objects.

Now, you might be wondering – what a solar simulator is. You will learn about it as you scroll through this article! 

What is a Solar Simulator?

A solar simulator, also known as the artificial sun, is a device that produces light, closely resembling natural sunlight. 

The main function of a solar simulator is to create controlled experiment environments for testing solar cells, sunscreens, polymers, and other products. 

Types of a Solar Simulator

To understand deeply about solar simulators, you must know what their types are. Solar simulators come in three basic variants: 

• Continuous
• Flashed
• Pulsed

#1. Continuous Simulator

A continuous simulator is most frequently used for low-intensity testing. The most astonishing fact about it is that its intensity ranges from less than one sun to several suns. 

Continuous solar simulators combine multiple types of lamps (such as an arc source and halogen lamps) to expand the spectrum into the infrared. 

#2. Flashed Simulator

The next variant of the solar simulator is the flashed simulator. It incorporates flash tubes and is qualitatively comparable to flash photography. 

A flashed simulator is generally used for high-intensity testing. It can range to several thousand suns, attainable within a few milliseconds. 

What’s its crucial feature? Well, this device is frequently used to stop unnecessary heat accumulation in the gadget under inspection.

#3. Pulsed Simulator

The last type of a solar simulator is the pulsed solar simulator which uses a shutter to block and unblock light from a continuous source immediately. The pulses typically range between 100 and 800 milliseconds (ms) (for special Xe Long Pulse Systems).

Now, let us learn about the next category in solar simulators, i.e., the solar simulator grades. 

Solar simulator: what are the grades?

Solar simulators may differ as per the wavelengths and light variations. Different types of lamps are employed as light sources within the solar simulators. 

These lamps determine the wavelength of the transmission system, while optical filters may change the wavelength. The beam optics defines the effectiveness and light pattern.

Based on these characteristics, solar simulators are commonly graded into three categories: A, B, or C. Their characteristics include —

• wavelength resemblance to sunlight, 
• non-uniformity of the light ray, and 
• long-term stability of the light ray. 

If the grade and limits for these characteristics are not mentioned anywhere, the chances are it will be a xenon light source rather than a solar simulator.

The table below shows the different grades of a solar simulator. 

Grade	Spectral (wavelength) resemblance to sunlight	Irradiance Spatial Non-Uniformity	Temporal Instability(long-term)
Class A	0.75 – 1.25	2%	2%
Class B	0.6 – 1.4	5%	5%
Class C	0.4 – 2.0	10%	10%

Lamps Used in Solar Simulators

There are different lamps used in solar simulators for constant illumination. These are: 

• Xenon: The xenon arc lamp is the most popular lamp used in continuous and flashing solar simulators. These lamps provide strong illumination with an unfiltered range that resembles natural sunlight.

• Metal Halide: The metal halide arc lamp is mainly used in cinemas and television lighting systems. These lamps are used in gadgets that require temporal stability and a close match to daylight.

• QTH: The quartz tungsten halogen (QTH) lamp produces wavelengths that can closely match the radiations produced by the black body. However, it normally has a lower colour temperature than the actual sun. 

• LED: Light-emitting diodes (LED) are one of the latest inventions in solar simulators. They can produce energy-efficient artificial sunlight radiation.

UV Radiation from Solar Simulator: Risks and Hazards

With ample pros of solar simulators, there are a few risks and hazards associated with them. They release UV rays through visible to infrared radiation. UV radiation (UVR) poses the greatest risk to human health. 

Even working for a short period without protective gear can result in acute harm. Therefore, it is important to set the maximum exposure limits and determine the acute cutoff. 

Additional Risks Associated with Solar Simulators

There are a few additional risks associated with the use of solar simulators. Let’s take a deep dive into these risks. 

Lamp Explosion

Arc lamps, when used with solar simulators, contain high-pressure gas that might explode if performed incorrectly. Don’t handle or touch the lamp’s glass panel. 

You should clean the fingerprints with isopropyl alcohol and fresh tissue, or it can make the lamp casing less durable.

Install the lamp using the correct electrical wiring voltage. When tightening electrical connections, avoid stressing the glass components. 

When the lamp’s duration is complete, replace it. It’s important to change an old lamp that has darkened because it increases the risk of explosion.

Mercury (Hg)

Mercury-based arc lights are used in several solar simulators (Hg or HgXe). These mercury toxicities can spread in the air if the lamp cracks or explodes. Therefore, it’s advised to speak with an industry expert on handling mercury pollution properly.

Conclusion

If the term solar simulator sounded alien to you earlier, hopefully, after reading this article you now know everything about it. 

A solar simulator is used to analyse solar wavelength and irradiance.  

Although there are risks associated with it, they unleash only if you handle the device carelessly. Careful handling eliminates all risks and cons.

FAQs

Q. How is a solar simulator put to use?

Continuous solar simulators feature lamps that offer consistent light for several hours, while pulsed solar simulators use electric arc lamps (like Xenon arc lamps).

Q. What is the purpose of a solar simulator?

A solar simulator is a device that produces light that closely resembles sunlight. Solar simulators evaluate solar cells in controlled indoor environments under controlled laboratory settings. In solar simulators, various lamps have been employed as light sources.