Hi.

On the follow photo you may see the standard induced tester,which the led inside
turns-on when you hold the metal tip of the screwdriver and move it close to sockets,
hot AC electric wire,etc.


My question is:what is the minimum strength of signal,that,usually makes the led to start turn-on?(the sensitivity).

 

I have no idea but I can tell you that it varies depending on whether you have your finger on the screw head at the opposite end to the probe.

 

Is it a led, or a neon bulb?

 

It's an led + a circuit + a battery.

 

As AlbertHall mentioned,it is led + a circuit + a battery.
But anyone know what is,more or less the minimum strength of signal
,that,usually makes the led to start turn-on?

 

Some model's (rated 120 - 240Vac ) I have seen would trigger at around 50 Vac , but I have seen them as low as 32 also .

 

I didn't refer to the Vac voltage,i refered to the power of the RF strength.(electric field strength/magnetic field strength).
What is the minimum electric field strength(RF signals)that makes the led turn-on?

 

That obviously depends, inter alia, on the circuitry used, which may differ according to the manufacturer.

 

xchcui.......it will depend on what the screwdriver is meant to measure. Most testers like that are to indicate AC power.....not rf.
I have not seen nor could I find a led tester like that on google.
If you are in a country that uses 120 ac.......then about 50-60 volts of ac (or rf).............will lite a neon bulb.

If you want to measure weak rf fields..............there are many other circuits to choose from.

 

That obviously depends, inter alia, on the circuitry used, which may differ according to the manufacturer.

You don't have to mention the exactly field strength of that particular tester.It will be enough to know,in general what is the minimum strength signal that will start turn-on the led.
I don't know which unit is exactly appropriate to use,but can you answer that question by using:mV/m(field intensity/strength)unit or maybe other unit?

 

can you answer that question by using:mV/m(field intensity/strength)unit or maybe other unit?

Sorry, I can't answer that. There are too many variables.

 

You don't have to mention the exactly field strength of that particular tester.It will be enough to know,in general what is the minimum strength signal that will start turn-on the led.
I don't know which unit is exactly appropriate to use,but can you answer that question by using:mV/m(field intensity/strength)unit or maybe other unit?

Given that nobody knows an answer to that question why don't you measure it and let us all know.

 

Given that nobody knows an answer to that question why don't you measure it and let us all know.

Are you joking,right.
If i had a measurment equipment,why should i bother you with that question?!
Anyway,thanks for your responses.