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Multimeter low voltage diode check output upgrade?

Pexy

Feb 21, 2016
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Feb 21, 2016
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Greetings!
Today I bought my second multimeter. It's a UNI-T UT-33A.
It works great and displays exact same numbers as my older UT-33D except the diode check but with LEDs.
It doesn't want to light up the LEDs like the 33D does because the diode check voltage is 1.6V unlike 2.9V of the 33D. Is it because the 33A uses 2xAA batteries insted of 1x9V battery like 33D does?
Can I somehow turn up the 1.6V voltage on the output so I can visually inspect the LEDs or should i just stick with it?
Thanks
 

Terry01

Jul 5, 2017
206
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Jul 5, 2017
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I think you stuck with the 1.6v unless you really know how the insides work. There probably will be a way to change it but I doubt it will be as simple as changing a battery out.
In saying that there are some very clever guys on the forum so one may have an easy fix for you.
Good luck however you go.
 

Audioguru

Sep 24, 2016
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My Fluke multimeter uses a 9V battery and its diode test lights up only some LEDs dimly. The current is so low that the forward voltage display is useless. Use a new 9V alkaline battery with a 360 ohm series resistor instead.
 

Terry01

Jul 5, 2017
206
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My Fluke multimeter uses a 9V battery and its diode test lights up only some LEDs dimly. The current is so low that the forward voltage display is useless. Use a new 9V alkaline battery with a 360 ohm series resistor instead.

What fluke do you own?
They must change it quite a bit on all their meters.
I have the 177 and 289. The 177 uses a 9v battery and gives out over 7v on the diode test. The 289 uses 6 x AA’s and gives out 5.2v ish. I have the Brymen 867s too which gives out a poor 2.9v, one feature where I feel the Brymen is found really wanting more. I have a cheap Chinese meter I’ve had for years that is very accurate when matched up with any of my other meters but that meter also only manages around 1.5v on the diode test.
Funny how they are all so different. You’d think there would be a set number or whatever.
 

Audioguru

Sep 24, 2016
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So if i power it like this it might work?
It will light an LED. Then you measure the forward voltage across the LED with a voltmeter.
Do not connect the LED with backwards polarity.
 
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