Large Sphere Calibration for Flux Measurements

With the recent boost in LED-based replacement lamps for fluorescent lighting, accurate testing of these devices is becoming extremely important to ensure consistency both in color and in brightness. To accurately test these sources for both color and total luminous flux, an integrating sphere is often used. We’ll explain the requirements for performing optical testing using an integrating sphere, as well as walk you through the process of calibration.

Characteristics of a Properly Designed Integrating Sphere

The integrating sphere chosen should have a high reflectivity coating, preferably >98% to ensure a good response. The sphere should also be properly fitted with baffles to prevent direct rays from impinging upon the detector port. A NIST traceable total spectral flux standard should always be used in conjunction with an auxiliary lamp to correct for any self-absorption of the test sample.

The exit port of the sphere should include a diffuser to guarantee the detector is able to “see” the entire sphere and not just the backside of the baffle.

4 Step Calibration/Measurement Process for Total Luminous Flux

To obtain an accurate total luminous flux measurement, the following steps of calibration/measurement process should be used.


  • Install the NIST traceable standard of total radiant flux at the center of the sphere and provide power at the specified current setting. Using the OL 770 software, you can then take a reading of lamp output.
  • Shut down the standard lamp, but do not remove it from the sphere and then power the auxiliary lamp and allow it to stabilize. Measure the auxiliary lamp and save the file for future reference. This is simply a transfer calibration, making the auxiliary lamp a temporary calibration lamp.
  • While keeping the auxiliary lamp powered, remove the NIST traceable standard lamp and install your test fixture into the sphere. Open the calibration software and measure the auxiliary lamp again, this time with your test sample installed, but not yet powered. You’ve now created a total spectral flux system response calibration.
  • With this new calibration loaded into the software, you can power your test lamp and allow it to stabilize prior to measuring.

Learn More About Gooch & Housego’s Integrating Spheres

Gooch & Housego offers a variety of integrating spheres for your optical testing needs. For more information on our products, don’t hesitate to contact our sales team today toll-free at 800-899-3171.

Spectral Imaging for Geologic Analysis

Spectroscopy has been a popular way to identify minerals and geologic materials in the visible to near-IR, shortwave-IR, as well as longwave-IR spectral regions. This approach has formed the basis for measurements using spectral imaging taken remotely, which is actually comprised of imagery in hundreds of different spectral bands with a unique spectrum at each image pixel.

While visible to near-IR (VNIR) and shortwave-IR (SWIR) measurements have been relatively easy to obtain for decades, longwave-IR (LWIR) has been much more difficult. It is only recently that full range HSI data analysis has been able to be gathered.

New research is focused on improving identification and also the ability to map geologic materials using information from the full spectral range. Using data from NASA’s imaging spectrometer spanning the VNIR-SWIR and data covering the LWIR, researchers were able to apply a standard approach to analyze the HSI data.  

Individual analysis of the SWIR AVIRIS and VNIR, as well as LWIR hyperspectral data for each range, provided extremely rich and complex data patterns. Researchers were able to directly relate spatial materials and spectral endmembers to geological processes and physiochemical properties based on emissivity minima, geologic context, and specific reflectance absorption. This unique mapping approach showcases some similarities that are not easily observed by simply mapping the spectrally predominant material in individual ranges. The combined VNIR-SWIR-LWIR combined mapping led to results that could not have been accomplished with a single spectral range.

Spectral Imaging in High Demand

As the market for spectral imaging continues to grow, Gooch & Housego is proud to offer a variety of spectral imagers and spectroradiometers for truthing and reference to clients of all capabilities. For more information on Gooch & Housego’s products and services, don’t hesitate to call 800-899-3171, or fill out their contact form online.

The Future of LEDs is Very Bright

The entire lighting industry has changed significantly over the past several years, thanks in large part to LED testing and lighting technology. Long life, efficiency, quality of light, and lower carbon emissions have all been factors in the growing market share of this relatively new lighting source.

Researchers at the Industrial Technology Research Institute suggest that the worldwide LED lighting market was worth $30.5 billion as of 2014 and should increase to roughly $51.6 billion by 2018. As new technologies continue to be released, the future of LED lighting seems quite promising.

Cost No Longer a Hindrance to Market Growth

When LEDs were first being introduced, the largest barrier to adoption was primarily price. However, in 2012, this began to change as competition increased and production costs began to decrease. With the price decrease, the improved return on investment made more companies begin to look at LED lighting as a viable and economical alternative to traditional lighting fixtures.

Presently, most LEDs offer a rough average of 115 lm/W, but many manufacturers claim they have the capability to produce 200 lm/W light sources, which would only need 5W to produce the equivalent amount of light from a 60W incandescent bulb.

Longevity Key to Success of LED Lighting

Some manufacturers claim to have performed LED testing that show their products have the capacity to last up to 100,000 hours. While some dispute these claims, the point is that LED lighting lasts many times longer than incandescent bulbs at prices that continue to look more favorable.

Return on Investment Depends on a Number of Factors

The return on investment of LED lighting depends on a variety of factors, including energy considerations, maintenance, life, color quality, and consistency. As technology continues to improve, there is no doubt that LED lighting will one day outpace traditional incandescent lighting in commercial, as well as residential, applications. For more information on LED testing systems, please call Gooch & Housego at 800-899-3171.

Huge Growth Expected in LED Usage in NVIS

While LED usage is growing in almost all aspects of the lighting industry, night vision imaging system (NVIS) lighting is being used in a variety of applications, including law enforcement, military, and emergency services. This market should see a rise from just under $75 million in 2014 to over $178 million in 2021, based on findings in a recent research study.

Military Continues to Dominate the NVIS Compatible Lighting Market

The usage of LEDs in night vision applications by the military continues to dominate the entire NVIS lighting market. The use of LEDs in military night-vision technology grew from just over $60 million in 2013 to over $72 million in 2014.

The primary increase in LED use in night vision compatible lighting devices is being driven by a variety of dynamics including:

  • Size
  • Weight
  • Durability
  • Technological innovations
  • Lower maintenance needs
  • Energy savings

Use of LEDs for Naval Ship & Watercraft Lighting

Another area where night vision imaging is experiencing growth is the naval/military sector. This sector is looking to utilize the latest in night vision technology as they attempt to convert a variety of military and naval ships. This type of LED lighting allows safety for personnel located on-board, while not affecting the ability for pilots to land safely using night vision goggles.

Law Enforcement and EMTs Also Seeing Benefit From New Technologies

Night vision technology is no longer just for military applications. Law enforcement and emergency personnel are beginning to use night vision technology to apprehend suspects, as well as to protect the public.

Bright Future for Night Vision Technology

As the market continues to grow, there will undoubtedly be all sorts of new avenues where night vision technology can be utilized. No longer is darkness a hindrance for military, law enforcement, or emergency personnel looking to do their jobs. For more information on Gooch & Housego’s products and services, such as NVIS compatibility testing systems, call 800-899-3171, or contact them online.

Night Vision is Now Appearing in Car Headlights

Everyone that has driven for more than a few years has undoubtedly had an experience when driving on a dark road to be surprised to see an animal, biker, or pedestrian in the road. This can be a very scary and dangerous situation. While headlights may help drivers see what is in front of them, they often don’t do a very good job of seeing anything off to the side. Thankfully, headlights, like most parts on new cars, are finally beginning to get smarter, thanks to night vision.

Ford Leading the Way with New Night Vision Technology Advancements

Ford has two new lights that are currently in development to help identify animals or people in the road earlier than traditional headlights. These technologies are meant to help identify subjects like animals, bicyclists, or pedestrians that are not equipped with any type of safety lighting.

One of the designs uses an infrared camera located in the front of the car to track up to eight objects simultaneously. If an object is recognized in the path of the car, a spotlight will shine on the subject and a warning will display on the dashboard.

Another type of night vision technology that Ford is testing involves widening the beam of headlights at bends in the road or intersections, which makes it easier to see if anyone is coming from the side. In addition, this system uses a camera to recognize lane markers and curves and uses GPS to customize lighting for a specific route. On roads that are unfamiliar, the system can store new details for future travel along the same route.

Foreign Car Makers Have Long Used Night Vision Assistance Technology

These attempts from Ford are not the first to help car owners better illuminate animals and pedestrians along dark routes. Mercedes, BMW, and Audi currently have systems in place to detect pedestrians or animals and alert the drivers. While these solutions are not as advanced as the new technology from Ford, it’s promising to see some of this technology in action.

New Technology Means Fewer Collisions

New technology offering collision warnings has been proven to reduce the number of crashes significantly. The Insurance Institute for Highway Safety states that collision warning technology alone can cut car accidents by between 7%-10%, and by adding automatic braking, this number goes up to around 15%.

Testing Key for Advances in Night Vision Technology

Large car manufacturers like Ford, Mercedes, BMW, and Audi are working hard to make driving safer. Through improving night vision technologies, it’s exciting to see these companies continue to innovate on an almost daily basis.

At Gooch & Housego, we understand the importance of thorough testing when developing new night vision technology. To help companies with night vision testing, we offer a variety of products including the OL 770-NVS Night Vision Display Test & Measurement System.  For more information about all of our testing equipment, don’t hesitate to contact us online, or by phone at 800-899-3171.

Integrating Spheres at Gooch & Housego

Gooch & Housego has been an integrating sphere manufacturer for over 20 years.  Integrating spheres are used for a variety of different applications. They are most often used to measure the total power or flux of a light source the sphere collects which can be compared against a reference photometric standard similarly measured.

Integrating Spheres from Gooch & Housego

Gooch & Housego offers a variety of integrating spheres ranging from one inch up to two meters, including spheres that are fully motorized. Our spheres can be used for a variety of measurements including:

Irradiance as Well as Illuminance Measurements

  • Nearly perfect cosine response
  • Standard as well as custom designs
  • Many different size options from 1 inch up to 76 inches
  • Wide range of wavelengths

Flux Measurements

  • Wide range of wavelengths
  • Many different sizes from 7 inches up to 76 inches
  • Washable coating available on larger spheres
  • Standard as well as custom designs
  • Auxiliary lamps included
  • Optimized design
  • Internal and external mounting options
  • Wide range of wavelengths

Calibration Sources for Reflectance and Transmittance Measurements

  • Large number of available accessories
  • Direct interface to instruments or through fiber optics
  • Dual beam construction
  • NIST traceable
  • Choose solutions that are either fully automated or manual
  • Range of light levels from high to extremely low
  • Calibrations for luminance, radiance, and irradiance

Are You Interested in More Information About Integrating Spheres?

If you’re in the market for integrating spheres, Gooch & Housego has a wide selection of solutions that will meet your needs. We offer a wide range of sphere sizes as well as multiple port and baffle configurations to meet your needs. For more information, feel free to contact our team online, or phone at 800-899-3171. We look forward to helping you meet your integrating sphere needs.

Museums Shifting to LEDs to Protect Precious Paintings

exhibition-362163_1280As museums around the world look to protect some of the most famous paintings from artists like Vincent van Gogh, few realize the harm that light can have on the darkening of bright colors in these iconic paintings. The yellow pigment used specifically by van Gogh has darkened so noticeably over time that other artists have started using other pigments entirely.

Museums Switching to LED Lighting

As companies look to not only save money, but also better protect their paintings, they’re looking to LED lighting in droves.

Scientists have identified the colors of light that are most damaging to paintings, which are typically blue and UV light. In the past, art museums would put UV filters over their incandescent bulbs, but LEDs make it much simpler by not emitting UV light at all.

LED Innovations Leading to Less Damage to Paintings

However, LED light is still light and, therefore, can damage paintings. Scientists have therefore been working hard to find ways to minimize this damage. One way is through the creation of LED lights that offer users the ability to change the direction of the light. This allows art museums to better direct light sources to minimize the amount of light that is directly hitting precious paintings. Another way museums are protecting paintings is by minimizing the amount of overhead light. Art lovers visit museums for the art, and by dimming the overall gallery, it doesn’t detract from a typical day at the museum.

LED Tunabilty Offers Additional Creativity

One of the benefits of LED lighting is the ability to play around with different varieties of lighting in a museum. Artists can use different types of LED lighting to make objects look completely different, which opens up the possibilities for the lighting itself to be a part of art exhibits around the world.

LED Testing Key to Protecting Paintings

LED testing is especially important when lights will be used to illuminate valuable paintings.  At Gooch & Housego, we offer a variety of testing equipment, such as the OL 770-LED that allow lighting manufacturers to ensure their products will meet all necessary industry standards.

IKEA to Only Sell LEDs By 2016

the-lights-231485_1280Modern furniture retailer, IKEA, recently announced that by 2016, the company plans to replace all of its traditional lighting fixtures with LED lights. IKEA claims that it will be the first US furniture retailer to move toward selling LED lighting exclusively, and points to the many environmental benefits of LEDs as the reason for the change. And what are some of the benefits of using LEDs? Spectroradiometer manufacturer, Gooch & Housego, lists some of the benefits of using LEDs over traditional incandescent light bulbs.

Costs of LED Lighting Continue to Fall

While many may look at this move as cost prohibitive for a variety of consumers, thanks to advances in LED testing and technology, LEDs are must more affordable than ever before.  IKEA contends that they will be selling LED bulbs at the lowest prices in the market (currently their lowest priced bulb starts at $9.99).

Renewed Focus on Longevity

While IKEA’s furniture is not always looked upon as long lasting, IKEA claims that its LED bulbs will last up to 20 years, which is comparable to other major manufacturers, such as Philips that sell bulbs at much higher price points.

What Does This Means for the Lighting Industry?

As large companies like IKEA make a vow to utilize LED lighting exclusively, other companies will no doubt follow to gain traction and notoriety in their markets. This is great news for energy conservationists that are focused on renewable resources. LED lighting is no doubt the future of inexpensive, yet extremely efficient lighting in all types of industries.

Gooch & Housego Commends IKEA On Their Stance on LED Lighting

At Gooch & Housego, we commend IKEA for taking a stand when it comes to LED lighting.  The reality is that if more companies were to take a similar stance, they would command much more buying power with LED manufacturers, allowing prices for LED bulbs to continue to fall. We hope that as more companies follow IKEA’s lead, we’ll see a worldwide adoption to LED lighting.

Gooch & Housego offers a variety of spectroradiometers and LED testing equipment, like the OL 770-LED, that lighting manufacturers use to ensure their lighting products meet certain regulatory standards. If you have questions about any of our products, don’t hesitate to reach out to our support team today at 800-899-3171.

That Salad You’re Eating? It May Have Been Grown by LEDs

Philips has recently opened GrowWise City, an indoor farm based in the Netherlands. This indoor experiment is meant to perform research into how our world can respond to the ever-growing demands for more food with a limited amount of usable farmland.

Details of GrowWise City Environment

GrowWise City is completely LED powered and covers a whopping 2,500 square feet of area.  Researchers are attempting to develop what they’re calling “LED light growth recipes” that allow farmers to grow crops using LED lighting for the entire year without the need for soil or sunlight.

The environment at GrowWise is completely clean and closed so that no natural light or air can enter the space. The site uses a completely customized LED system that can provide varying sequences of light based on the unique needs of different plants. This unique targeting of nutrients will allow farmers to grow produce vegetables that are fully pesticide-free and 100% organic.

The area is made up of four layers of plant racks in eight different rooms, all with differing climates. Each layer of the racks use Philips’ GreenPower LEDs, which have been specifically developed to work with growing crops. These unique LEDs are able to be customized-based on the unique needs of the plants.

Wide Array of Applications for This Type of Lighting

Currently, researchers are focused on recipes to grow herbs, strawberries, and leafy vegetables, but once these have been mastered, researchers can move towards other crops, like wheat and potatoes.

LED Testing Key to Safety

When you’re dealing with LED lighting in close proximity to a food source, it’s important that proper LED testing is conducted to ensure that the lighting fixtures are safe. At Gooch & Housego, our OL 770-LED offers lighting manufacturers an easy way to ensure that their LED fixtures are 100% safe, even when used in a facility that grows a variety of crops. To learn more about our LED measurement equipment, contact our team today at 800-899-3171.

5 Bridges in NYC to Use LED Lights

New York City residents will be excited to hear that decorative LED lights are about to be installed on bridges over the Codorus Creek in New York City. County commissioners recently approved a deal that will allow a local nonprofit, Downtown Inc, to install LED lights on five county-owned bridges.

  • Benefits of LED Lighting: These new decorative LED lights will be installed on the railings of these bridges and will allow light to be cast onto the sidewalks as well as portions of the Codorus Creek.
  • Variety of Lighting Options Being Considered: There are a variety of different lighting options being considered. One option is just to use standard white LED lights, while another is to use lights that can change colors. This would allow the bridges to be lit up with various colors for different community events and holidays.  The versatility of LED lighting offers a whole host of economical and attractive lighting options for York City.
  • Lights Also Meant for Safety: At least one of the bridges will also feature a motion sensor light that will trigger the LED lights when someone is walking under the bridge.

While New York City is starting with just five bridges, they’re hoping to expand this initiative to a variety of other bridges in the city. Since this project is just in its infancy stages, it could take years to complete.

All LED Lighting Subject to Intense Testing

Before any type of LED lighting can be installed, rigorous LED testing must take place to ensure that fixtures are not emitting dangerous levels of radiation. Using LED measurement equipment, like the OL 770-LED from Gooch & Housego, companies can ensure that their lighting equipment meets certain specifications laid out by the government. For more information about the OL 770-LED, don’t hesitate to contact the Gooch & Housego sales team today at 800-899-3171.