Help with the EX330 Multimeter

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tikishark
 
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Help with the EX330 Multimeter

Post by tikishark »

I just received a new EX330 and had a few questions. When I'm measuring Alkaline "AA" batteries am I supposed to be getting a high reading (1.76-1.80 volts)? Is this within an acceptable range of 1.5V battery? When I hook up an LED and switch over to the diode test... I notice that I get a faint light on the LED, but nothing happens on the meter. A non-light emitting diode will display a voltage, but not when testing a LED... Is this supposed to happen? I also get some really crazy readings when measuring capacitors. A 220 microfarad ranges on the meter from .016 all the way up to 5.84; a ceramic 104 capacitor reads at 61.6 instead of 100.

To make sure that this isn't a battery issue, I put new batteries in the unit. I also tested every component on a breadboard in isolation to avoid getting a reading from an additional component.

Do you think I have a defective unit?

Thanks... John

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adafruit_support_bill
 
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Re: Help with the EX330 Multimeter

Post by adafruit_support_bill »

When I'm measuring Alkaline "AA" batteries am I supposed to be getting a high reading (1.76-1.80 volts)? Is this within an acceptable range of 1.5V battery?
That is not unusual for fresh high-quality alkaline cells. They quickly drop to about 1.5v, then decline steadily over their useful life. If you get readings like that from a set of used cells, I would be concerned.
Image
I notice that I get a faint light on the LED, but nothing happens on the meter. A non-light emitting diode will display a voltage, but not when testing a LED... Is this supposed to happen?
The diode test is for standard diodes. It doesn't work with most LEDs.
I also get some really crazy readings when measuring capacitors. A 220 microfarad ranges on the meter from .016 all the way up to 5.84; a ceramic 104 capacitor reads at 61.6 instead of 100.
The meter is rated for capacitors up to 200uF. And it will take several minutes for a capacitor that large to charge. You have to wait until the readings settle before ending the test. Small capacitors without a tolerance code can be +80%/-20% and readings can be influenced by a lot of things. Just the way you hold the leads in your hand can give you a 100nF swing.

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tikishark
 
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Re: Help with the EX330 Multimeter

Post by tikishark »

Thank you for the information. With the exception of the battery reading (which always reads how no matter what type or age of battery I use), and capacitors the other measures are settling down. With the capacitor, I followed the instructions from the manual and allowed up to three minutes for everything to stabilize, but I still get really weird readings. I'm going to try a friend's meter tomorrow and see how far everything is off.

I appreciate the support.

John

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adafruit_support_bill
 
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Re: Help with the EX330 Multimeter

Post by adafruit_support_bill »

Let us know how the readings compare with your friend's meter. Batteries are not a great reference voltage since they change over time. Try something like the 5v pin on an Arduino, or the two outer pins on a USB port.

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tikishark
 
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Re: Help with the EX330 Multimeter

Post by tikishark »

adafruit_support_bill wrote:Let us know how the readings compare with your friend's meter. Batteries are not a great reference voltage since they change over time. Try something like the 5v pin on an Arduino, or the two outer pins on a USB port.
Okay - Everything checks out... the two tests you suggested came up with correct values and my friend's meter matched...

Thanks again for all the help....

John

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