Ammeter HowTo

Introduction

Measure Current in Series

To measure current through a particular loop of your circuit, connect the ammeter in series with the other elements in the circuit loop. This means you must physically modify your circuit in the following way:

create a gap in the segment where you want to measure the current.
Reconnect the gap using your ammeter as a jumper wire

Notes

Notice that all of the current flowing in the circuit actually flows through the ammeter. Thus, the internal resistance of an ammeter is very small.
You can use the ammeter to measure the direction of current flow, provided to follow the convention of red to positive.
Because the ammeter is placed in series with the other circuit elements, you must physically alter your circuit in order to measure current with an ammeter.