Testing lighbulb using multimeter

[zillah]

One pin type or bayonet bulb the two terminals are the silver/grey bumps at the bottom not the side case

Yes this is what I meant

 

[siggy]

Yes bayonet is push twist

 

[zillah]

Nice picture siggy

 

[siggy]

Test across the bumps and see should get reading

 

[jackorocko]

as long as the bulb is good, then you should get a reading less then OL across the two bumps on the bottom. If the bulb is blown, then you will OL and you know the bulb is toast.

With incandescent bulbs the resistance value is not very important. It will either work or not, this is why I use the diode test feature on the meter. It will give an audible sound when there is continuity and no sound when there is no continuity. That's all that matters with incandescent bulbs for them to work or not. Makes it easy, because then you don't have to look at the meter, you can concentrate on holding the probes on the correct place.

 

[zillah]

Test across the bumps and see should get reading

Unfortunate it was OL Mega ohms reading

 

[zillah]

this is why I use the diode test feature on the meter.

Do you mean continuity ?

 

[jackorocko]

Do you mean continuity ?

yes, you are checking for continuity.

 

[jackorocko]

Unfortunate it was OL Mega ohms reading

then the bulb is blown then. It should not work when hooked up.

 

[zillah]

It will either work or not, this is why I use the diode test feature on the meter. It will give an audible sound when there is continuity and no sound when there is no continuity.

Hi
Today I have done this test with two fridge light bulb same as the one below :

http://www.wickes.co.uk/philips-40w-ses-cooker-hood-bulb-pk2/invt/218920/

One light bulb burned out for sure and other is working (for sure it is working)

on DMM Push the select key to .))))) continuity (not --<I- diode) try to test both fridge lights bulb, non of them the buzzer sounded!!!!!!!

 

[(*steve*)]

on DMM Push the select key to .))))) continuity (not --<I- diode) try to test both fridge lights bulb, non of them the buzzer sounded!!!!!!!

Use a resistance range. Say 2K, or something like that.

Testing the 2 bulbs should show different results. If they don't, you're doing something wrong.

Low wattage bulbs may have a resistance high enough that "continuity" buzzers don't sound.

 

[zillah]

Hi Steve

On DMM I tried the resistance and I use select ohms symbol (not kilo ohms nor Mega ohms)
Yes on the working fridge light bulb DMM read 106 ohms and on the burned out it read OL.

Now my query why continuity didn't work ????

Regards

 

[siggy]

Turn on continuity touch probe tips together what happens?

 

[Rleo6965]

Hi
Today I have done this test with two fridge light bulb same as the one below :

http://www.wickes.co.uk/philips-40w-ses-cooker-hood-bulb-pk2/invt/218920/

One light bulb burned out for sure and other is working (for sure it is working)

on DMM Push the select key to .))))) continuity (not --<I- diode) try to test both fridge lights bulb, non of them the buzzer sounded!!!!!!!

Some Multimeter unable to emit sound if measured resistance was below required resistance for buzzer sound or continuity test. Mine was 40 Ohm. That is, it will measure 106 ohms for working bulb but will not emit beep sound.

 

[zillah]

Turn on continuity touch probe tips together what happens?

Beeps

 

[siggy]

Beeps

No need to swear cuz you don't know the answer

Oh it beeps not bleeps hahahahahahahaha

Rleo probably correct do you have the instruction manual

 

[zillah]

Some Multimeter unable to emit sound if measured resistance was below required resistance for buzzer sound or continuity test. Mine was 40 Ohm. That is, it will measure 106 ohms for working bulb but will not emit beep sound.

Okay that makes sense.
But when I checked the resistance for the working light bulb it was 106 ohms (I have checked the manual for my DMM, I couldn't find minimum value for resistance for the buzzer to beep ), then I would expect the continuity test should beep for the working bulb , but that didn't happen !!!!!

 

[(*steve*)]

then I would expect the continuity test should beep for the working bulb , but that didn't happen !!!!!

I think the reason it didn't has been explained twice, once in one of your quotes.

Here goes #3

The continuity buzzer will not sound if the resistance exceeds some value (and only your instruction manual can tell you that value). The resistance of a low wattage bulb is evidentially greater than this value, so no beeping or buzzing.