Edison Tech Center Pi Day Quiz 2020

1) Most light bulbs today are specified by lumen output. This is measured by placing the lightbulb in an integrating sphere which reflects all of the light output onto a sensor. However, in use, the user is sometimes only interested in the light output over a specific area, like a worktable. This is measured in lux, the intensity of light that hits an area. One lux is defined as the intensity of one lumen measured one meter away over one meter squared (m^2) area. Using Pi in the equation, what is the conversion equation between lumen and lux at a distance r from the lightbulb?

2) How many lux are there on a table one meter wide by one meter long which is illuminated by a 840 lumen lightbulb which is one meter away from the lightbulb?

3) How many lux are there on a table one meter wide by one meter long which is illuminated by a 840 lumen lightbulb which is 1.75 meters away from the lightbulb?

4) If a safety officer says that the illumination of a worktable must be 538 lux, but it is currently measured at 269 lux, how much closer does the lighting need to be to the worktable?

5) If the illumination of a worktable must be 538 lux, but it is currently measured at 54 lux, design a single lens system to increase the lighting to at least 538 lux.

6) If the illumination must be 538 lux, but it is currently 54 lux, and illumination is additive, how many more light bulbs would be needed to increase the lighting to at least 538 lux?

7) What eight year old computer system has sold over 30 million computers?

Universe of Instrumention Unit 2 Production Begins

February marked the start of video production for part two of the Universe of Instrumentation – a program highlighting tools (instruments) used by electrical engineers.

Better measurement technology leads to better technology in general:

The Edison Tech Center’s learning program entitled Universe of Instrumentation was first started in 2015 with help from the IEEE Circuits and Systems Society. The program allows young people to learn about how we measure electricity, time, light energy and other basics.¬† These basics are the building blocks of all technology as better ways of measuring things leads to better technology. The program audience consists of tech-minded young people and features interviews with engineers as well as talks on historical instruments.

In alignment with the Edison Tech Center’s overall goal, the program promotes an understanding of the full continuum of electrical technology from the 1840s to today.

1940s oscilloscopes, 1980s computers (Atari) and 2020 cutting edge are joined to show the progression of measurement technology, and in Unit II we are focusing on time measurement.

Corporate and Government participation:

We’d like to thank the following corporations for allowing us access to experts in various fields:

  • Ball Aerospace
  • Seagate Technologies
  • National Institute of Standards and Technology

Time measurement in Unit II

For computers, phones, GPS and other technology we need to establish standards of timing. Whether its measuring wavelengths of star light or having computers communicate precise time measurement is needed. So where is the “clock” in your electronics? We examine a cross-section of devices and talk about how crystals, optics, mechanical devices, and atomic clocks keep time.

In unit one we covered how electricity is measured, and in unit two you will see how time measurement was combined with electric meters to make AC power possible.

Reaching our audience:

The Universe of Instrumentation project has reached over 95,000 people since we released unit one, now we look to expand our videos and written web content in unit two.

Universe of Instrumentation Course >

The Edison Tech Center Has Moved

The Edison Tech Center has moved to the Gazette building in Schenectady from its former location on North Broadway (2001-2019).

Online reach has exceeded our walk-in visitors since the online programs began in 2007. Our niche audience of just a few million  are spread out across the US and globe, so when it came time to scale down and keep overhead lower we moved to a location that is better suited for long-term operation. The Edison Tech Center and its tens of thousands of technological artifacts are still in use for video productions and research projects.

Gathering together technology from our archives to shoot the new Universe of Instrumentation videos in 2020.

Digital Reach of the Edison Tech Center

The organization as of February 2020 has over 71,000 video subscribers and 13 million views in the online video distribution network. Our two websites reach tens of thousands of students and engineers each month through more than 200 pages on technology history. Our main website EdisonTechCenter.org is undergoing updates so some information on our organization may be out of date.  EdisonTC.org is our news and blog page as well as home of certain programs such as the Universe of Instrumentation.

233+ videos online:


See our articles by subject below:

AC Power History articles – the surprising history of the electric power grid and its many innovators >
Electric Light History Pages – the 13 major categories of electric light >
Universe of Instrumentation Program – on instruments used by engineers >