Using an Integrating Sphere for Reflectance Spectroscopy

Introduction of Integrating Sphere:
The integrating sphere is a hollow sphere. The shell is generally made of metal. The inside of the shell is coated with a mansion. There are two or several light holes on the wall. The working principle of the integrating sphere is shown below. The light transmitted by the light source becomes parallel to the inside of the integrating sphere through the concentration sphere through the consecutive light mirror and lapse. In the end, the outlet is uniformly shot. Through the detection of the optical flux of the light port, data such as reflectivity and transmission rate can be converted according to the formula.

The integrating sphere system is generally used to test the spectrum power distribution, color, color temperature and other parameters of the light source, and transparent plastic. The test of the reflectance parameters is not very accurate, and the glass transparent plastic, optical film and other materials the reflectivity test does not have a clear national standard method for reference. The test system mentioned in the “Optical Level Percentage Based on Double -Board Sphere” has improved the accuracy of the reflectivity test using the integrating sphere system testing of the reflectivity test to a certain extent. It can be used as a test method for reference.

Applications:
The optical sphere works with a Spectroradiometer to do the photometry, colorimetry and radiometry parameters measurement.

Conditions for a good integrating sphere:
A. The surface of the integrating sphere is a complete geometric sphere, which is equal to the radius;
B. The inner wall of the sphere is a neutral uniform shot surface, which has the same man -reflex ratio for various wavelength incident light;
C. There are no objects in the sphere, and the light source is also regarded as glowing without physical abstract light sources.

Factors affecting the measurement accuracy of integrating sphere:
A. The inner wall of the sphere is a uniform ideal drift layer, obeying Langbo’s rules;
B. The reflectivity of each point in the inner wall of the sphere is equal;
C. The white coating of the inner wall of the sphere is neutral;
D. The radius of the sphere is equal everywhere. There are no other objects except the lights in the integrating sphere;
Therefore, the inner wall of the integrating sphere will be played and stripped off, and the yellow change will affect its measurement accuracy.

LISUN have the below diameter of integrating sphere:
• IS-0.3M/IS-0.5M is for LEDs, LED modules, mini LED bulbs & other small lamps. The flux testing range is 0.001 to 1,999 lm
• IS-1.0MA is for CFL or LED bulbs. The flux testing range is 0.1 to 199,990 lm
• IS-1.5MA/IS-1.75MA is for CFL, LED bulb and tube, fluorescent lamp, CCFL. The flux testing range is 0.1 to 1,999,900 lm
• IS-2.0MA is for HID lamps or high power lamps. The flux testing range is 0.1 to 1,999,900lm

How to install and operate the integrating sphere?
First of all, we know what equipment composition of the spectrometer &integrating sphere system: a complete set of spectrometer integrating sphere systems by the spectroradiometer, Optic fiber, digital power meter(measurement of electrical ginseng), AC power supply (power supply to the measured material), DC power supply (DC power supply ( Power measuring power supply to standard lights or DC inputs), integrating sphere (judgment according to the size of the lamp measurement), standard lamp (setting the integrating sphere standard) and cabinet (integrated all equipment). First of all, you need to do the following steps before the test:

1. Check the connection of all equipment and confirm that all the connection is correct and safe (the connection here includes the connection between the equipment and the equipment and the power supply);
2. Open the computer software and set related parameters (such as setting data and parameters needed);
3. Install the standard lamp in the correct position in the integrating sphere. Please follow the laboratory operation standards;
4. After installing the standard lamp, turn on the DC power supply, and enter the software in the setting of the standard light calibration report one by one. After confirming, click to start the preheating standard lamp and standard. After the standard is successful, turn off the DC power supply to remove the standard light, and switch the power to AC power supply;
5. Install the lamp (please note that the type of lamps is required. If the lamp is tested, the lamps are glowing around, such as LED integrating sphere bubbles, CFL energy -saving lamps, etc. The lamp measurement is directed, such as street lights, LED panel lights, etc. It is best to install the lamp on the position of the integrating sphere -side opening to do 2π test), install the lamp measurement, turn on the AC power supply, and set it in the test software to set up a quilt. The warm -up time of the lamp is usually stabilized for the LED light source output for about 10 minutes;
6. After the warm -up, the software will automatically analyze and calculate the corresponding data. At this time, the software interface will display the test results and print out the test report;
7. After completing the above action, you need to turn off the power and total control power switch of each instrument.

Why use the integrating and when is required to use the integrating sphere?
Generally speaking, if the optical diffuser is used carefully, it can reduce the tiny error caused by the uneven distribution of the incident light source on the detector or the shift of the beam during measurement, so it can improve the accuracy of the measurement. However, when a more precise measurement, the integrating sphere must be used as optical diffuser to minimize the test error.

When using the integrating sphere to measure the optical flux, the measurement results can be more reliable. The integrating sphere can be reduced and removed and removed from the glory shape, divergent angle, and the measurement error caused by different positions on the detector.

The integrating sphere can be used to use it with the spectroradiometer. The light output holes of the integrating sphere are connected to the incident port of the spectrometer through the fiber to make the accuracy of the measurement significantly improved. This measurement method is widely used in LED measurement and various lamp measurements.

How long does it take to set and maintain?
Most customers care about this issue. In principle, the standard is set once a week, and the difference will not exceed 5LM. Blow the dust gun once a month to keep the equipment clean and tidy. If you find that the inner wall of the integrating sphere is dropped or damaged, you can contact LISUN to buy paint or buy new integrating sphere to replacement. How long is the maintenance of the customer’s own comparison of the test results and the use of equipment, there is no fixed period request.

Under what kind of environment (room temperature, humidity)
The relative humidity of running/storage should be less than or equal to 80%, and water -free steam condensation should be condensed. The relative temperature requirements of running storage are appropriate to be about 25 degrees. Because the lamp work itself will produce temperature, if the temperature difference between the integrating sphere is relatively large, the inner wall reflection will affect.

Lisun Instruments Limited was found by LISUN GROUP in 2003. LISUN quality system has been strictly certified by ISO9001:2015. As a CIE Membership, LISUN products are designed based on CIE, IEC and other international or national standards. All products passed CE certificate and authenticated by the third party lab.

Our main products are Goniophotometer, Integrating Sphere, Spectroradiometer, Surge Generator, ESD Simulator Guns, EMI Receiver, EMC Test Equipment, Electrical Safety Tester, Environmental Chamber, Temperature Chamber, Climate Chamber, Thermal Chamber, Salt Spray Test, Dust Test Chamber, Waterproof Test, RoHS Test (EDXRF), Glow Wire Test and Needle Flame Test.

Please feel free to contact us if you need any support.
Tech Dep: Service@Lisungroup.com, Cell/WhatsApp:+8615317907381
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Tags：LPCE-2 (LMS-9000) , LPCE-3