CoCoRaHS Manual Rain Gauge

The CoCoRaHS rain gauge is a good quality manual rain gauge, specially designed for use by amateur observers for making rainfall measurements of good accuracy but utilising a more affordable gauge than the traditional Snowdon design. It is a traditional manual rain gauge, which needs to be read and emptied daily in order to maintain an accurate year-round rainfall record but may nonetheless be useful to customers of our automatic stations who might wish to use a manual check gauge for calibration and reference purposes.

The CoCoRaHS gauge is a more affordable option because it is made from high-quality plastics rather than copper, but is nonetheless of solid and durable construction using heavy-duty, UV-resistant polycarbonate. The gauge is about 350mm (14") tall and has a precision-dimensioned 100mm (4") diameter funnel opening, affording it greater accuracy than cheap narrow gauges. The funnel directs its collected rain into a calibrated inner measuring tube with a capacity of 25mm (1") rainfall. On the relatively rare (in the UK) occasions when daily rainfall might exceed 25mm, excess rainfall spills over into and is retained by the outer collecting tube, which has an overall capacity of 275mm (11"). Measuring rainfall >25mm is then effected by - carefully - filling the accurate inner measuring tube with the collected rainfall in 25mm batches until the outer reservoir is emptied

The gauge is also supplied with an easy-to-install quick-connect bracket - this bracket can be screwed to, for example, a vertical wooden post (as shown right) to secure the gauge. The main gauge body is then a slide-fit over the bracket making it quick and easy to remove the gauge for measurement and cleaning. A one-year log-sheet for recording daily rainfall data is also supplied free with each gauge.

This gauge is extensively used in the official US weather community. ('CoCoRaHS'is an abbreviation for the US-based 'Community Collaborative Rain, Hail and Snow Network'. Because this rain gauge is officially approved for use by the network of CoCoRaHS observers it has been thoroughly tested and its readings fully validated. For example, in one year-long comparative study the CoCoRaHS gauge measured an annual rainfall amount within 3% of the total recorded by an official US 8" reference gauge.

The CoCoRaHS manual rain gauge is available with either metric or inch calibrations.

Full details about the key features and use of the CoCoRaHS manual rain gauge are provided on the CoCoRaHS manual rain gauge page at our Main Site.