Need a light measuring tool

[Bee.talbot]

So, for the Group 4 project, my partners and I are measuring how pH affects the glowing of the bacteria Vibrio fischeri. So, we have the set up, and we know that we want to measure the output of light from our different samples of the bacteria, but I have been at a loss for days as to what instrument would be best to use for measuring the light - and one I can easily get my hands on.

Any suggestions? Has anyone tried to do something like this before?

[Sonneteer_Trombonist]

The instrument that I have used to calculate light output is a light meter, which is a short grey wand type thing that attaches to a CBL. This, in turn, attaches to your graphing calculator. By adding a Physics program to your calculator, the light-meter will tell you the intensity of whatever light it is pointing towards. It also measures the light coming from the overhead lights in the room, so you should either turn those off or take a baseline reading with only the room's overhead lights on and then subtract that from your total.

So, in short, a light-meter wand, a CBL, graphing calculator, physics program. All this stuff is in my school's lab, so hopefully it is for you too, and if not your lab techs should be able to find it fairly easily.

[Sandwich]

You can also get light intensity meters which give you the reading straight off. Your Biology department should have some form of equipment, if you ask, it's a pretty standard experiment.

Light intensity meters are very variable though, at least in my experience! I'd advise you to try and tape it somewhere to keep it as consistent as possible, the readings jetted around wildly whenever we used them.

[Bee.talbot]

Interesting...I will look into those. Thank you very much! However, does the light intensity meter send out light in order to measure absorbency/transparancy, like a colorimeter or spectrometer? I only want a reading of the glow from the bacteria, after all, so this would be a problem.