colweather.org.uk

I'm experiencing a problem with this. Rain droplets are adhering to the funnel, therefore not all rain is dripping into the container, and consequently the amount measured is low, e.g: 3.1mm compared to 3.3mm in a nearby copper Snowdon gauge.
The manufacturer recommended a petroleum based product wiped inside the funnel, however this has not worked.

Suggestions, and an explanation of the physics involved appreciated. This adhesion does not occur in the Snowdon Gauge.

My Hellman gauge is not stainless steel and I have not had any problems at all. It compares very well with the standard and Casella recoding gauge nearby. It is of course only used for recoding rain intensity and time on the trace.
Have you thought of spraying it with waterproofing solution? It may not last but should work. Alternatively car polish should do the trick.

Mike

Thank you for your reply, Mike.

I finally resolved the problem by taking the Gauge out of service, and submerging the funnel in a rainwater butt.
I've just taken it out after 2 months. The droplets no longer adhere to the inside of the funnel.

I guess the funnel has been coated with a thin layer of algae. Hope it doesn't wash off!