Keith Nuttle wrote:

I am posting this to the woodworking group because wood workers know a
lot about everything. ;-)

I am a volunteer at church and one of things that I do is change the
florescent lights when they die. Most of the fixtures are four tube
fixtures.

Is there a test to tell if a Florescent light tube is bad and needs to
be replaced, or the light is not working because its companion is dead?

I have struggled with this. Sometimes when one of the tubes is replaced
the other seems to start working. So it would be nice to test the tube
to see if even though working it should be replaced.

If you have enough bulbs to check to justify a $120 investment...

https://www.amazon.com/Milwaukee-221...dp/B007EEXAQG/

https://www.youtube.com/watch?v=uxTMF8mAXVo

https://www.youtube.com/watch?v=sQ4nQgiaYK4