Rainfall values read incorrect - 'hidden multiplier'?

[gerardwood]

I installed Cumulus MX yesterday, adding in all my old data from Cumulus 1. Everything generally went without a hitch, apart from a strange anomaly with the rainfall counter - what was reported as 30.45in in Cumulus 1 AND on the Davis VP2 console was showing as 38.67in in Cumulus MX (causing all sorts of fun with the records, I suddenly had 8.22in of rain falling at once).

I couldn't find any reason for this to have happened, so I reset the rain the counter via the interface, and manually corrected the data/ini files this morning. Everything looked fine again.

Today, it's rained. Davis console reports 0.27in of rain; Cumulus MX says 0.35in... again it's too high, and it looks like is the same % increase, around 27%. There's definitely no '1.27' multiplier set in config anywhere that I can see. The only thing I can think of is related to the rain collector configuration, I recall it can be set to either 0.2mm or 0.01in... and the latter is 1.27 times the former... could this be it?

Regards,
Gerard.
http://www.musburyvillage.co.uk/weather

[steve]

Do you have a metric rain gauge (despite using inches in Cumulus)?

In converting the number of gauge clicks to actual amounts, I have assumed that people using MM in Cumulus have a metric rain gauge, and those using inches have a 0.01" rain gauge. This can be over-ridden by adding a line to the [Station] section of Cumulus.ini:

VPrainGaugeType=0

Where 0 is a 0.2mm gauge and 1 is a 0.01" gauge.

[gerardwood]

Hi Steve,

Thanks for the quick reply. Yes, it's a metric VP which I choose to display in imperial. Old fashioned

I tried setting VPrainGaugeType=0 which appeared to make no difference on restart.

Just to be sure, I set VPrainGaugeType=1 and restarted, and it made a right mess of the rainfall records again

I've now put it back to VPrainGaugeType=0, and just had a look at the log files; rain counter is at 30.73 which is CORRECT. It says the day start value was 30.38, which is wrong - it was 30.46 at the start of the day. Seems to have gone backwards. Maybe it will sort itself by tomorrow. Will investigate further later.

Thanks again for you help.

[steve]

I'm curious as to why you have your rain gauge set to metric, when you want to record in inches - wouldn't it be logical to have the gauge record in the same units, to avoid conversion and rounding issues?