Reading a multimeter - units

In summary, the user is trying to determine the correct units for the data they are reading off their multimeter. They have tested with a known resistor and battery, but the results seem odd. Other users suggest trying a different battery and resistor and checking the manual for their specific multimeter. It is concluded that the measurement is likely in milliamps.
  • #1
Cspeed
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I am trying to make sure that the data I read off my multimeter has the right units.

I have a multimeter that is a similar model to this one:
http://www.tequipment.net/BK2703B.html
You can enlarge the image to see the settings.

When I measure AC current, my result says "2.95" when the setting is on 20m/10A, using the mA and COM ports (this model doesn't seem to have AC current, but the DC current has the same label). Is it 2.95 milliamperes?

Thanks.
 
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  • #2
I hate autoranging.

Put a known resistor on battery (know current) and see what the meter says.
 
  • #3
This is odd. I'm just using V = I*R, with .235 V, 38.3 ohms, and it should be .00671 amps. I put the meter on 20m/10A, and it spit out 2.71. That's still in the milliamp range, but I'm just not sure if I want to trust it. I'd hate to have done all the work getting these results, just to use the wrong units.

Does anyone know for sure how to interpret the results? I hope AC doesn't have any affect on it.
 
  • #4
It looks like the impendance of your meter is comparable with 38 ohms, when in 20mA mode. That would reduce the current you actually get.

Try a 9V battery with a 1k or 10k ohm resistor and see what you get.

EDIT: I just realized something. 2.71 A is way over the range of a 20mA range setting. So it must be 2.71 mA ... but checking things out by doing a measurement like you are doing is definitely a good thing, it helps you learn about and become more familiar with your meter.
 
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  • #5
2.95 should be mA, but I would think that since the meter doesn't measure AC current, it is just a bogus reading.
 
  • #6
The one I linked to isn't the model I have - mine does measure AC (it has a switch for Ac/DC).

After some more testing it seems that any of the settings that are labeled with an 'm' like 20m or 200m are measured in milliamps. Thanks for your help.
 
  • #7
I'd recommend having a read-over of the manual for your particular multimeter:
http://www.bkprecision.com/

(That's assuming it's actually manufactured by BK Precision)
 
  • #8
I've looked over the manual - no help in there. I think I'm safe to assume it was .00295 Amps.
 
  • #9
russ_watters said:
2.95 should be mA, but I would think that since the meter doesn't measure AC current, it is just a bogus reading.

this
 

1. What are the basic units on a multimeter?

The basic units on a multimeter are volts (V), amps (A), and ohms (Ω). These units are used to measure voltage, current, and resistance respectively.

2. How do I switch between units on a multimeter?

To switch between units on a multimeter, use the selector knob or button to select the desired unit. Make sure to set the correct range for the unit you are measuring to get an accurate reading.

3. What is the difference between AC and DC voltage on a multimeter?

AC (alternating current) voltage is the type of electrical current found in most household outlets, while DC (direct current) voltage is the type found in batteries. Most multimeters have a setting to measure both AC and DC voltage.

4. Can a multimeter measure temperature?

Some multimeters have a temperature setting that allows them to measure temperature using a temperature probe. However, not all multimeters have this capability, so it is important to check the specifications of your particular model.

5. How do I interpret the units shown on a multimeter?

The units shown on a multimeter indicate the measurement being taken. For example, if the unit is set to measure volts, the display will show the voltage in volts (V). It is important to pay attention to the range setting and any other symbols or abbreviations on the display to ensure an accurate reading.

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