QM1323 Multi meter -What is the red light built in used for ?

[tytower]

I have one of these QM1323 MMś and the red lamp flashes with no apparently consistent reason. Does anyone know what its for ?


Cat III Multimeter with Temperature


• Data hold
• Relative measurement
• Case included

A budget-priced meter with everything you need - capacitance, temperature and 10A on AC and DC, compact and light weight with rugged moulded case.

Specifications

Category: Cat III 600V
Display: 4000 count
Basic accuracy: 1%
DC voltage: 600V
AC voltage: 600V
DC current: 10A
AC current: 10A
Resistance: 40Mohms
Temperature: -50 - 760°C (-4 - 1400°F)
Capacitance: 40µF
Frequency: 5MHz
Ave/RMS: True RMS
Dimensions: 137(H) x 65(W) x 35(D)mm

 

[audioguru]

The operating instructions will say what the red light is for.
Maybe it is a low battery indicator?

 

[bountyhunter]

Maybe it is a low battery indicator?

I was just thinking that. Amazing how many battery operated equipment designers think:

"When the battery is almost dead, we need to light an LED to throw additional load on it to make sure it dies quickly."

 

[EN0]

I was just thinking that. Amazing how many battery operated equipment designers think:

"When the battery is almost dead, we need to light an LED to throw additional load on it to make sure it dies quickly."

Those LED's will take such a small current it isn't going to have much effect on the battery.

 

[audioguru]

The little 9V alkaline battery in my Fluke LCD multimeter lasts almost "forever". It turns itself off if it is idle for a few minutes. The low battery indicator uses the low power LCD display, not an LED.

 

[EN0]

Either way, it only takes a negligible amount of current. LCD's are low power as well.

 

[bountyhunter]

Either way, it only takes a negligible amount of current. LCD's are low power as well.

A bright LED will burn about 10mA, which I would not want to be giving away on any portable 9V instrument. If the LCD display is lit anyway, there is no added power wasted showing a low battery indicator there, but external LEDs are just a dumb design idea.

 

[EN0]

A bright LED will burn about 10mA, which I would not want to be giving away on any portable 9V instrument. If the LCD display is lit anyway, there is no added power wasted showing a low battery indicator there, but external LEDs are just a dumb design idea.

bountyhunter,

Sure, a bright LED will do that, but any portable equipment wouldn't want to consume 10mA for a dinky little LED. That is why they have LED's that require much less current; specifically for those applications.

 

[tytower]

Well what a complete load of shite !
You think I didn't read the manual properly ? Of course I did that was the first place I want . Not a mention of it . Then I went to their web site -Vendor and Manufacturer-nothing
So I ask here
And what do I get
A discussion on LED current consumption
As I said - Shite

Have a look at your posts and then tell me you are right and helpful.
Of course a fellow is going to get a bad reputation from such as you simply because you need a kick up the bum !


After some thought for anyone who is even remotely interested is it may be related to frequency measurement as when I bring it near a strong frequency source it lights up and if I put 1 probe on a transformer lamination it will go on (while it is switched off) and then if I switch the MM on and set to frequency I can measure the 50Hz cycle.

 

[bountyhunter]

I beg a thousand pardons.....

(deep bow..... not easy with my bad back)

You should contact the forum administrator immediately and demand a refund.

Oh, wait.... that's right....... never mind

 

[john1]

Thats cheered me up no end.
Ive had a good laugh, and believe me i needed it.

Cheers Tytower.

 

[EN0]

Whew! I just about fell outta my chair!

 

[JimB]

Well, now you have thrown all of your toys out of the cot, consider that maybe no one here has or knows anything about this DMM.

You think I didn't read the manual properly ? Of course I did that was the first place I want . Not a mention of it . Then I went to their web site -Vendor and Manufacturer-nothing
So I ask here.

You did not tell us that you had looked in the manual and the manufacturers website (who does make it, that is not obvious) we probably would not have suggested to RTFM.
Given the number of lazy students who come here asking for info which is as easily found as this discussion board, this is sadly a conditioned reaction. (Pavlov would enjoy it here!).

And what do I get
A discussion on LED current consumption .

Well, an LED on an LCD DMM is a bit strange in my opinion.

After some thought for anyone who is even remotely interested is it may be related to frequency measurement as when I bring it near a strong frequency source it lights up and if I put 1 probe on a transformer lamination it will go on (while it is switched off) and then if I switch the MM on and set to frequency I can measure the 50Hz cycle.

I can only comment that I have never seen a feature like that before.

JimB

 

[Mr RB]

1. it might be indicating when it changes range from DC to AC etc that matches your symptoms

2. it might indicate when it has saved an "autohold" reading, also matches your symptoms

3. please post the diagram from the instructions that shows the controls etc and their names, it's hard to believe the light is not shown or labeled

 

[john1]

Could it be to show theres a cable in the wall ?

Havent got one of these myself, so i'm just guessing.
You mentioned it will light up near an ac source,
even if its switched off, so it might be for showing
wiring hidden in the wall.

When you find out its proper function, i would like to know.

John

 

[audioguru]

Maybe the warning LED indicates that there is a high voltage nearby or is being measured. Maybe it is actually a neon bulb since it lights even with the MM turned off.

 

[tytower]

Good stuff .Now were getting somewhere anyway. I held it against the power point switched off and the bulb lit and stayed lit . Moving it across the wall (Masonry block) above the power point where the cable runs and this did not light it . Tapping it on the wall does light it for half a sec. All with the MM switched off.

Edit- I also put it next to a power cord with power flowing and it lit up from about 2 inches out

Its a bit bright for a LED and may well be a neon.If I tap it with my finger it lights for a sec also -its got me beat

 

[tytower]

I was playing with an Arduino starter kit today and got to looking at a vibration sensor. They seem to give a voltage increase as vibrations increase and I wonder if this is what it is.Would they build these into a multimeter and if so why?

 

[DCRTAS]

It indicates electrical noise

 

[exploroz]

I have just bought one for a present for a family member. I don't think it measures electrical noise at all . The led comes on when it senses vibration . With the switch either on or off it will light up . The meter was on the table and when I threw my keys on the table the led lit up . If you move the leads it lights up , you bump the unit it lights up . The instructions do not mention it , they do not even have it on the diagram which shows you the components with discriptions . Any help will be appreciated .

Thanks Peter