Most of the rain gauges that are available work in much the same way. However, you still need to think about your application and whether you need to rent or lease a professional grade gauge or if you should get a consumer grade gauge instead. There are a number of different styles available as well, and the measurements are easier to take and record today thanks to better quality technology and materials.
How rain gauges work
The gauges in use today work on the same principal as those that were in use a hundred years ago. The gauges feature a large cylinder that has a funnel located at the top. This funnel collects the rain into a measuring tube. The tube has a tenth of the cross section area as the top of the funnel. This means that half an inch of rain (five-tenths) would fill five inches of the tube. In most rain gauges, this would cause an overflow, which would then be poured into the measuring tube after first emptying out the water it has already collected.
The device allows meteorologists to determine the amount of rainfall very accurately. The measurements are usually to one-hundredth of an inch. They are also able to measure precipitation from snow and hail using these gauges. However, the process is somewhat different. They need to remove the funnel and the inner tube. Then, they will collect the hail or snow from the outer cylinder and melt it so they can get a reading. This takes longer, but they can still produce some very accurate results about the amount of precipitation that has fallen.
About rain gauges
Rain Gauge Manufacturers
Some of the popular brands of rain gauge include Siemens, Scientific Sales, and Miles Kimball.