Rain gauges are used to measure the amount of rainfall over a given amount of time.
When measured by meteorologists, rain (or other forms of precipitation such as snow) that has fallen is collected in a rain guage. These sophisticated pieces of equipment can accurately measure the levels of very small amounts of rain.
Although rain gauges in professional use are extremely accurate and expensive, approximations of these gauges can be made at home for precipitation measurement, either to calculate average rainfalls over a longer period of time or to measure rainfall levels after one occasion of rain.
Instructions
Preparation
1. Take an empty plastic bottle to act as the rain catcher. The slimmer the bottle is, the more accurate the measurements can be, as the spaces between increments will be larger.
2. Cut the top off the bottle at a level where it is at maximum width; this will ensure that the part of the catcher that collects rain is as wide as possible and will not fall into the bottom part of the bottle.
3. Tape the removed top of the bottle upside-down on the bottom section so that it makes a funnel through which the rain can fall. Including this funnel rather than simply leaving the rest of the bottle open will minimize the amount of collected rainfall that is lost due to evaporation through the top of the catcher.
4. Draw some measurements onto the side of the catcher. Measure from the bottom of the catcher using a ruler. The markings should be made in the smallest increments possible to ensure the most accurate measurements. Make these marks with permanent marker.
5. Dig a hole approximately half the height of the rain catcher and place the catcher inside. The top of the catcher must be above ground level to prevent any insects from falling into it. Placing the catcher in the hole will prevent it from falling over and spilling its contents.
Measurement
6. Remove the catcher from the ground following rainfall or the duration of time for which you wish to measure the amount of rain.
7. Place the catcher on a flat surface and look at the level of water in the bottom of the catcher, using the increments you drew. Record this level.
8. Replace the rain catcher in the hole for further measurements of rainfall.
Tags: rain catcher, accurate measurements, bottom catcher, bottom catcher using, catcher hole