Topic: Vantage Pro 2 low rain readings

[WheatonRon]

Here is what I am dealing with--copied from another thread in this Forum--amounts are in inches. Both VP2s have new rain collectors communicating via new PCBAs (all manufactured in 2016 by Davis) so it can't be the age of the equipment.

Today (October 1, 2016), we had the perfect rain. Steady but not hard rain over 5 hours. Results? Mr. CoCo 1.05, Rainwise 111 1.05, VP2 station A --.71, and VP2 station B--.90. Obviously, the VP2s need some calibration! All stations within 50'. I would expect some differences but the VP2s are off the mark, particularly station A.

[desrae20]

I believe .01" is the tipping amount, so you are approx 34 tips out on VP2-A, how many turns have you screwed the adjustment nuts out.
Incidentally I put a texture mark on the top of the nuts to help adjust each side the same.
Des

[WheatonRon]

I believe .01" is the tipping amount, so you are approx 34 tips out on VP2-A, how many turns have you screwed the adjustment nuts out.
Incidentally I put a texture mark on the top of the nuts to help adjust each side the same.
Des

Unfortunately, snow is coming shortly so this calibration exercise may have to wait, but 34 tips out can't  be right even if the math says so!  I complained to Davis but no response yet!

[ValentineWeather]

Which brings up another issue. I think even my heated bucket under counts about 20-25% with snowfall. I pretty much just rely on the manual gauges and adjust accordingly.

[desrae20]

Snow is something we do not have to contend with.
I had to screw the nuts out 3.6 turns, it is a concern when Davis claim they are adjusted before sale.
For say 1", each bucket must tip 50 times (assuming its adjusted right at .01"), so using the maths each bucket needed to tip about 17 to 18 more times over the 5hr period, I think this is a possible error.
Enjoy the snow.
Des

[WheatonRon]

Which brings up another issue. I think even my heated bucket under counts about 20-25% with snowfall. I pretty much just rely on the manual gauges and adjust accordingly.

Do you think the difference results from evaporation?

[WheatonRon]

Snow is something we do not have to contend with.
I had to screw the nuts out 3.6 turns, it is a concern when Davis claim they are adjusted before sale.
For say 1", each bucket must tip 50 times (assuming its adjusted right at .01"), so using the maths each bucket needed to tip about 17 to 18 more times over the 5hr period, I think this is a possible error.
Enjoy the snow.
Des

How much snow would you like? I can send you some, air collect, however!

[WheatonRon]

Snow is something we do not have to contend with.
I had to screw the nuts out 3.6 turns, it is a concern when Davis claim they are adjusted before sale.
For say 1", each bucket must tip 50 times (assuming its adjusted right at .01"), so using the maths each bucket needed to tip about 17 to 18 more times over the 5hr period, I think this is a possible error.
Enjoy the snow.
Des

In the other thread, I informed readers that Davis states its rain collectors are "laser calibrated." I have yet to grasp what this means! Maybe someone south of the equator can explain this to those of us north of the equator!

[ValentineWeather]

Which brings up another issue. I think even my heated bucket under counts about 20-25% with snowfall. I pretty much just rely on the manual gauges and adjust accordingly.

Do you think the difference results from evaporation?

Evaporation does play a roll along with other issues like flakes being diverted because of rising hot air over the bucket from the heater, plus the obvious issue with wind causing poor catch rate on all gauges.

[WheatonRon]

Which brings up another issue. I think even my heated bucket under counts about 20-25% with snowfall. I pretty much just rely on the manual gauges and adjust accordingly.

Do you think the difference results from evaporation?

Evaporation does play a roll along with other issues like flakes being diverted because of rising hot air over the bucket from the heater, plus the obvious issue with wind causing poor catch rate on all gauges.

I guess that is why I rely strictly on Mr. CoCo in the winter. It is a hassle (melting snow and remeasuring) but decent accuracy results and not having to worry about falling off a ladder servicing the VP2 ISS in the winter!