There are four typical forms of rain gauge. If you want to know more about these four forms in order to check out which type of rain gauge you would need, according to your specific purposes, then read on.
1.) The Graduated Cylinder or Standard Rain Gauge – this type was developed as the dawn of the 20th century approaches. It consists of a graduated cylinder with a funnel attached to it, placed in a larger container. The container contains the water that could overflow from the graduated cylinder. In measuring its results, the graduated cylinder is measured and the excess water that overflowed will be placed onto another graduated cylinder and measured again.
The usual measurement in the cylinder is millimeters and each of the horizontal line in it can be 0.2 mm or 0.007 inch. The usual measure of a graduated cylinder is only up to 25 mm or .098 inch. Anything over 25 mm will then flow over onto the small hole on the graduated cylinder’s top. This rain gauge utilizes a metal pipe attached to the larger container for adjustment purposes, just to make sure that it is level. Then, a metal rod placed on the ground will be fit over the pipe.
2.) Weighing Precipitation Gauge – A storage bin comprises this type of gauge. This bin is used to record the rainfall mass by weighing it. Some models of this gauge makes use of pen and rotating drum in order to get the mass, while in some models, a data logger is utilized which is attached to the bin through a vibrating wire.
This rain gauge type is usually more advantageous than the other type of rain gauge, commonly known as tipping bucket. It can measure other precipitation forms, such as the solid form of hail, sleet and snow and does not erroneously underestimate an intense or heavy rain. However, while it could generate far more accurate data, it is also quite expensive and needs maintenance more than the tipping bucket gauge.
Aside from measuring the total amount of rain on a given area for a specific period, the weighing rain gauge also has the ability to generate how much chemicals are present in the given area’s atmosphere. Scientists who study how the release of greenhouse gasses into the atmosphere can affect acid rain levels would find the data generated from this, very helpful.
3.) Tipping Bucket Rain Gauge – this makes use of big copper cylinder that is staked on the ground. A funnel is placed on top of this cylinder in order to collect the rain and channel it.
Then, the precipitation caught will fall into a small bucket placed on a lever, like a scale or seesaw. Whenever the precipitation amounts become equal to 0.2 mm or 0.007 inches, the lever will tip upward and it will send down to the recorder. A pen that is supported by an arm attached on a geared wheel serves as the recorder. The geared wheel will move once every time the lever sends a signal and every time it moves, the pen arm would either go on an upward or downward motion and leaves a recording manifested on a graph.
As previously noted, this type of rain gauge is not very accurate because sometimes, the rainfall has already stopped even before the lever was tipped and the next rainfall may not take more in order to tip the lever.
However, it is advantageous because through its records one can determine if the rainfall has been light, moderate or heavy. Nowadays, the modern type of rain gauge already comprises of a plastic rain collector, which is balanced on a pivot. Then, it activates a switch whenever it tips consequently recorded electronically or transmitted onto a remote station.
4.) Optical rain gauge – this type is comprised of a collection funnel set in a row. Below each of the funnels is a covered space with laser diode and phototransistor detector.