Meter

Thread Starter

Mitch520

Joined Nov 10, 2007
3
Should the meter be in series/parallel when measuring current,voltage or resistance? Do you know why that is? Thank you
 

Distort10n

Joined Dec 25, 2006
429
Should the meter be in series/parallel when measuring current,voltage or resistance? Do you know why that is? Thank you
Voltmeter: parallel because you want to know what the voltage is across a particular element. If you put it in series then you are connecting to the same electrical point, and you will not measure any voltage.

Ammeter: series because the current must flow through the ammeter for it to determine the amount of charge flowing. Other members may have better knowledge on the mechanism that actually measures the current. Hall effect sensor perhaps...


Resistance: cannot be measured in circuit. There is a small amount of current that flows through your meter, and when other components are connected to the resistor in question those provide a current path. The reading will not be valid. You need to tombstone surface mount components or lift up through hole components. Resistance is usually calculated knowing the current or voltage in the system.
 

hgmjr

Joined Jan 28, 2005
9,029
I suggest you review the material available in the AAC ebook on the topic of meters .

If you need clarification feel free to post you questions here.

hgmjr
 

Thread Starter

Mitch520

Joined Nov 10, 2007
3
Taking a class at work for Basic Electronics DC and the question on the quiz was

a. When measuring current, the meter should be in series/parallel.
b. '' '' voltage,'' '' '' ''
c. " " resistance, " " " "


Thank you
 

thingmaker3

Joined May 16, 2005
5,084
Measure resistance in parallel, but never with power applied in the circuit. If one attempted to measure resistance in series with the meter, one would be measuring the air between the meter leads.
 

Thread Starter

Mitch520

Joined Nov 10, 2007
3
Still not sure what you mean, all I want to know is when the meter is in series/parallel which one am I measuring? Thanks.
 

thingmaker3

Joined May 16, 2005
5,084
The cart needs to go behind the horse, not in front of her.

First, decide what you want to measure. Then set up the meter appropriately.

If you want to measure Volts, set the meter switches correctly, and hook the meter in parallel. Circuit power must be on.

If you want to measure Amps, set the meter switches correctly and hook the meter in series. Circuit power must be on.

If you want to measure Ohms, insure circuit power is OFF, set the meter switches correctly, and hook the meter in parallel. Meter can be damaged if one attempts to measure resistance with power applied to circuit.
 
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