DIY Rain Gauge

[Jack Harrison]

The Mk.1 version was a simple rectangular container.   OK, allowance needs to be made for rounded corners and the fact that the sides aren’t quite parallel but we are talking about principles here, not the finer points.  However even after a wet day like today with 14 mms rain so far, the depth of water in the container would be only a little more than 14 mms and thus difficult to measure accurately.

 

Adding the bottles does not affect the catchment area but makes the water depth that much greater.  Pie R Squared and all that sort of thing and you would arrive at a calibration factor, eg depth measured is say ten times rainfall.

 

The container shown in the photo is full as it represents several days rain.

 

I have yet to consider the implications of removal  of a bottle for alternative [primary] use during a rain event but the calculations should be easy enough before the alternative use is completed:-)

Jack

[Jack Harrison]

It has just been pointed out to me that the design illustrated is unsuitable for children.  For youngsters, Coca Cola bottles instead of wine/beer bottles could be used.

However the shape of Coke bottles would pose quite problem.  Perhaps a suitable testing question for an 'A' level maths exam.

Jack