... measuring higher currents, than your amperemeter can suffer, is made by shunt resistors - you simply measure the voltage drop of a defined resistor and calculate the drawn current with Ohm's law.
E.g. you use a resistor of 0.1 Ohm and measure a voltage across this resistor of 3 Volts -- then the drawn current is simply I = 3 [V] / 0.1 [Ohm] => 30 Amps ... so simply use the voltmeter ;)
E.g. you use a resistor of 0.1 Ohm and measure a voltage across this resistor of 3 Volts -- then the drawn current is simply I = 3 [V] / 0.1 [Ohm] => 30 Amps ... so simply use the voltmeter ;)