ammeters and voltmeters are alike in their design.
"Letters of a Radio-Engineer to His Son"
John Mills
In the case of the voltmeter, as you know, we have a large resistance in series with the current-measuring part for the reason of which I told in Letter 8. In the case of ammeters we sometimes let all the current go through the current-measuring part but generally we let only a certain fraction of it do so.
"Letters of a Radio-Engineer to His Son"
John Mills
ammeters used for measuring direct and alternating currents make use of the magnetic effects of the currents.
"The Radio Amateur's Hand Book"
A. Frederick Collins