It doesn't control something really....maybe itself though......

and yeah it has LED....but is it just red??? No....

1) An open refrigerator alarm, buzzes when the ref. light comes on. 2) a light meter. 3) a type of motondetector or headlight detector for the garage.

Rishieldjr, One of your 3 guesses are the CLOSEST of all guesses above!!!! Care to figure out specifially what this is?

I would go with light meter personally.

Close.....but its not a light meter......but pretty close.......so what is this for??? What is it?

A colour temperature meter maybe, or CRI meter

Wouldn't it be a device to see light spectrum?

#4 guess a frequency meter for finding 60hz or 50hz or HF ballasts like T8

Rishieldjr got it right...it tells if its electronic or maganetic ballast......works on MV, HPS, MH, and fluorescents! It is, believe it or not, called a discriminator!!!

Well I guessed right this time. We had someone come to survey the city's lights to convert to higher efficiency, and they used one of these although I didn't see it, I was only told about it.

It lights up green for electronic ballasts and red for maganetic

and thats useful again how?

Look at what Rich just said.....

But don't you have to get close to the ballast any ways, (you can just look at it)

I think it detects the flash pattern and then tells you whenever it's magnetic of electronic. I used my camera to do that before.

Okay that makes more sense.

How long do you think it will take to go up the ladder and open up EACH fixture looking at every one of them? It is faster to use the detector.....one of my friends used to do that for a living, looking and evaluate and survey the fixtures. He actually gave me this nice device....


The magnetic lights (and believe it or not incandescent) flashes 60 times a second while the electronic ballast will flash much faster frequency of like over 1000 HZ or more...I have tried this neat device on incandescent and it from 120 volts always turns out as "magnetic"

Now speaking of electronic and magnetic.....some of you may have known that NYC did a major changeover with 100/150 watt HPS and some left out MV fixtures with new OVG fixtures (they left alone the high wattage HPS) I have read they did that major changeover because the newer fixtures HPS ballast are electronic! So next time I go to NYC, I will bring the device and find out!

how far is the range on the "Discriminator"?

Remote for one of those remote-controlled outlet things that you can plug a lamp or whatever into.

Just read the comments to figure out what it is. That has to be the coolest thing. I didn't even know such a device existed.