Understanding IES LM-79 & IES LM-80

What are the limitations of LM-79?

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What are the limitations of LM-79?

As we all know about the strength of LM 79. Everything has its pros and cons. Let us have a look on the drawbacks of LM 79.

  • LM 79 depicts the parameters of the individual products. So the obtained Parameters cannot be used to access alike products.
  • Other limitation is the sample size. It does not state any sample size. So, the manufacturer provides only one sample instead of supplying more. This thus increases the vulnerability of lesser quality products.
  • This can be used only to determine complete luminary instead of LED used ( as based on absolute photometry) , which can produce different results due to quality of accessories used like glass, thermal effect, lenses etc.

If you’re Buyers Demanding for LM-79 Testing– Contact Now!

Wish this blog post will be help. If you have any other questions, please feel free to contact us. ITCIndia team looking forward work with you and get better together!

Mr. Puneet Sharma | Call: 08196980555 | E-mail: ITCIndiaOne@Gmail.Com

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What is LM 79 Test methodology?

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What is LM 79 Test methodology?

LM 79 is an approved method that describes the procedure to be followed and precautions to be observed in performing reproducible measurements of total Luminous flux, electrical power, luminous intensity distribution, chromaticity of Solid-State lighting products for illumination purposes under standard conditions.

LM 79 covers- LED based SSL products with control electronics and heat sinks. Luminaries (fixtures incorporating light source) as well integrated LED lamps.

LM 79 doesn’t cover fixtures without a light source, SSL products that require external operating.

LM 79


Test method for total luminous flux Measurements:

The total luminous flux of SSL product shall be measured with an Integrating Sphere or Goniophotometer. The method may be chosen depending upon what other measurements quantities (color, intensity distribution) need to be measured., the size of SSL products, and other requirements.

The integrating sphere is suited for total luminous flux and color measurements of integrated LED lamps and relative small size LED luminaries. Advantage of using integrating sphere is that it does not requires the “ Dark Room”., and also it is less time consuming.

The Goniophotometer provides measurements of Luminous Intensity Distribution as well as total luminous flux. It can take measurements of larger size luminaries as well as small size luminaries. It has to be installed in Dark Room. Measurements in goniophotometer are time consuming.

  Integrating Sphere Goniophotometer
Conditions No Dark room Dark Room
Size of SSL Small Size luminaries Large size as well as small size Luminaries
Measurements Total Luminous Flux Light Intensity Distribution , Total Luminous Flux
Duration of Test Fast Measurements Time consuming as compared to Sphere photometer.

If you’re Buyers Demanding for Luminaries  Testing– Contact Now!

Wish this blog post will be help. If you have any other questions, please feel free to contact us. ITCIndia team looking forward work with you and get better together!

Mr. Puneet Sharma | Call: 08196980555 | E-mail: ITCIndiaOne@Gmail.Com

Get Instant Quotations, Fill the Enquiry form: