The most accurate way to measure rainfall is to take a rain bucket of a known diameter (usually 12 or 24 inches) and place it on a scale. The scale subtracts the mass of the container from the mass of the rain.
They’re more accurate because they don’t underestimate the power of intense rain, which can actually affect the accuracy of an analog gauge and they can also measure other forms of precipitation including hail and snow.
Weighing gauges can even be equipped with a device that allows scientists to measure the quantity of chemicals contained in the atmosphere or a particular location through its rainfall. This is especially useful in studying the effects of greenhouse gases on the levels of acid rain.