There are a lot of instruments used to measure water volume. There's also the displacement method to measure liquids.
ruler
The instrument for measuring the angles of a triangle is called a protractor.
A ruler.
Protractors
caliper
Rain Guage
A spirometer measures the amount of air in lungs
volume
an 'ammeter'
Cusec
A thermometer
respiromterrespirometer
A flow meter.
a stopwatch
Potometer
dewpoint apparatus
A rain gauge measures in inches because it collects and measures the amount of precipitation that has fallen in an area.