Surge Protector - strange reaction to light sources?

[cf879]

Surge Protector -- strange reaction to light sources?

We have 2 power strips in our home in which the indicator lights both react to a light source in the following manner: during the day (in the presence of sunlight) the indicator lights shine red with a small flicker every now and then. In the dark, the indicator lights are off unless a light is shone on them, say from a flashlight etc. whereupon they light up red. When the flashlight or other light source is turned off or covered, they go off again. What in the world could cause the indicator lights to react in such a manner?

 

[Tom.G]

That is typical of Neon lamps at their end-of-life. As they age their ionization threshold voltage increases. The external light adds a little bit of energy to the gas, lowering the threshold voltage.

This can also be demonstrated with new Neon lamps by applying a voltage just below threshold and then shining a bright light on them.

p.s. Typical Neon lamp lifetime is 2000+ to perhaps 25000 hours and decreases with increased current. I have about a dozen outlet strips here with about 20000 hours on them. One lamp has failed and 8 others are very dim. Quality control seems to be lacking.