How do you measure railfall? What are the instruments used?What is the method used for doing this?

Question

Is there any rain metre?

Answer 1

Measurement of precipitation
Main article: Rain gauge
The standard way of measuring rainfall or snowfall is the standard rain gage, which can be found in 4-inch/100 mm plastic and 8-inch/200 mm metal varieties. [1] The inner cylinder is filled by 25 mm/1 inch of rain, with overflow flowing into the outer cylinder. Plastic gages will have markings on the inner cylinder down to 0.25 mm/0.01" resolution, which metal gages will require use of a stick designed with the appropriate 0.25 mm/0.01" markings. After the inner cylinder is filled, the amount inside it is discarded, then filled with the remaining rainfall in the outer cylinder until all the fluid in the outer cylinder is gone, adding to the overall total until the outer cylinder is empty. These gages are winterized by removing the funnel and inner cylinder and allowing the snow/freezing rain to collect inside the outer cylinder. Once the snowfall/ice is finished accumulating, or as you approach 300 mm/12", one can either bring it inside to melt, or use luke warm water to fill the inner cylinder with in order to melt the frozen precipitation in the outer cylinder, keeping track of the warm fluid added, which is subsequently subtracted from the overall total once all the ice/snow is melted.

Other types of gages include the popular wedge gage (the cheapest rain gage and most fragile), the tipping bucket rain gage [2], and the weighing rain gage [3]. The wedge and tipping bucket gages will have problems with snow. Attempts to compensate for snow/ice by warming the tipping bucket meet with limited success, since snow may sublimate if the gage is kept much above freezing. Weighing gages with antifreeze should do fine with snow, but again, the funnel needs to be removed before the event begins. For those looking to measure rainfall the most inexpensively, a can that is cylindrical with straight sides will act as a rain gage if left out in the open, but its accuracy will depend on what ruler you use to measure the rain with. Any of the above rain gages can be made at home, with enough know-how. [4]

Once someone has a device to measure precipitation, various networks exist across the United States and elsewhere where rainfall measurements can be submitted through the internet, such as CoCoRAHS [5] or GLOBE [6]. If a network is not available in the area where one lives, the nearest local weather office will likely be interested in the measurement. [7] An important use of precipitation data is for forecasting of river flows and river water quality using hydrology transport models such as SWMM, SHE or the DSSAM Model.

Answer 2

Measure Rainfall Using a Rain Gauge
The barometer must be hung on a wall or a post. Find a place outside for the rain gauge where there will be no run-off of rainwater from trees, roofs or signs. There is a minimum distance official rain gauges must be from obstructions such as these. If a nearby tree is five metres tall, the rain gauge must be at least twice the distance (10 metres) away.
Your rain gauge can be set up in three ways, but make sure it is safe from theft and damage (such as being trodden on).

To make a freestanding rain gauge, place the cylinder inside the black holder so the spike points up. This gives a flat base.

To fix the rain gauge to an object such as the top of a fence, secure the black holder to the vertical surface before inserting the cylinder.

To put the gauge at ground level, reverse the black holder so the spike points down (main picture) and stick it into the ground.

At am each day, record the rainfall, referring to the scale (in millimetres) on the cylinder. Then empty the cylinder. If you catch hail or snow, wait for it to melt before taking a reading.


Do’s and Don’ts
Make sure the rain gauge is in a safe location.

Make sure you take readings with the rainwater at eye level to avoid errors of parallax.



How does it Work?
A rain gauge measures rainfall (in millimetres) over a set period, usually 24 hours. Official rain gauges have a housing to protect the measuring cylinder inside. The top of the housing has a larger surface area than the top of the measuring cylinder and catches more rain than the cylinder would. The extra rainwater collected makes it easier to read the measuring cylinder and improves accuracy. A simple mathematical formula is used to correct the rainfall total to allow for the extra rainwater collected.

Click here for information on Precipitation

Answer 3

Rain measuring gauges are made by numerous firms, including Davis Instruments in California and Oregon Scientific. There are two general types: manual, and automatic. Manual gauges are simply graduated cylinders; after a rain, you just look to see how much rain is in the cylinder, and from time to time, dump it out. Automatic gauges often use a tipping bucket: there is a lever in the gauge, with a pair of little buckets on it; rain fills one bucket through a funnel, and then the lever tips, dumping the one bucket and positioning the other one to catch the rain. In the process, an electrical signal gets sent to a register.

Answer 4

Rain gauge is an instrument for measuring rainfall.

Answer 5

A protractor. The center is placed over the the angle and the bottom of the protractor is aligned with one of the lines of the angle. The angle measurement is determined based on where the other line of the angle intersects the protractor.

Answer 6

A rain gauge is used for measuring rainfall.
You can make a simple one yourself
try here

http://www.weatherwizkids.com/rain1.htm

Answer 7

Get a bucket, put it in the rain and when it stops, put a ruler in the water and measure it.

Answer 8

Rain gauge can be found at Home Depot.

Answer 9

You can get a rain gage in a hardware or discount store, and put it in your yard. It is a glass tube. I have one.