US rain collector on Vantage Vue

[steve]

Davis vantage pro2 us/metric version

So you have a metric rain gauge, and you told the console you have a metric rain gauge? So what's the problem?

[katdoc]

It goes metric if i put the adapter.but in my case there is no adapter.its lost or thrown away so until now although i checked on console metric units it used inches.in conclusion the station has the option for metric if you use the adapter.otherwise its inches.
Now the tip is 0,01" which is equal to 0,254mm instead of 0,2mm that the panel shows

[steve]

So you have an "inches" rain gauge. So you tell the console that you have an "inches" rain gauge. You don't need to change anything in Cumulus.

[katdoc]

So you have an "inches" rain gauge. So you tell the console that you have an "inches" rain gauge. You don't need to change anything in Cumulus.

and i change nothing to cumulus and it does the conversion to mm automatically?

[steve]

and i change nothing to cumulus and it does the conversion to mm automatically?

Yes; Cumulus displays and logs all data in the units you tell it to use when you first run it, regardless of what units the station uses.

[katdoc]

and i change nothing to cumulus and it does the conversion to mm automatically?

Yes; Cumulus displays and logs all data in the units you tell it to use when you first run it, regardless of what units the station uses.

You were very helpfull!Once again what a great piece of software!!! Do you believe that there will be no difference between this way and if i had installed the metric adaptor?
Im seeing now that although i changed the console to .01" it continues to show yesterdays rain in mm and so the rain rate in mm/hr?

[steve]

Do you believe that there will be no difference between this way and if i had installed the metric adaptor?

If you set the wrong gauge type in the console, then it will report the wrong value to Cumulus, and Cumulus will display the wrong values. It doesn't matter what units you choose to display it in. If you set the correct type of gauge in the console, it will report the correct value to Cumulus. I must be missing something. You've set the correct gauge type in the console, yes? So there's no problem.

Im seeing now that although i changed the console to .01" it continues to show yesterdays rain in mm and so the rain rate in mm/hr?

There are two completely unrelated settings. The first is to tell the console what type of rain gauge you have. You don't have any choice in this, you have to tell it what type of gauge you actually have. The second, unrelated, setting is what units you want the console to use to display the rain. It doesn't matter what type of gauge you have, you can choose any units.

[katdoc]

If you set the wrong gauge type in the console, then it will report the wrong value to Cumulus, and Cumulus will display the wrong values. It doesn't matter what units you choose to display it in. If you set the correct type of gauge in the console, it will report the correct value to Cumulus. I must be missing something. You've set the correct gauge type in the console, yes? So there's no problem.

Until now it was wrong.Now i set it to 0.01" which is actually the default gauge unless you use the metric adapter which i dont.

There are two completely unrelated settings. The first is to tell the console what type of rain gauge you have. You don't have any choice in this, you have to tell it what type of gauge you actually have. The second, unrelated, setting is what units you want the console to use to display the rain. It doesn't matter what type of gauge you have, you can choose any units.

i cant remember how you choose this.I thought that if you choose a gauge that counts the rain in inches the console will actually so the data in inches.

Ok you are right.I found the manual.Maybe im a kind of dumb but i did not understand the meaning of using the adapter after all.If you have us version you can display the units in metric so whats the problem?

[steve]

If you have us version you can display the units in metric so whats the problem?

It's just more accurate/precise to use the adaptor if you intend to use metric units. Without the adapter, one tip = 0.01 inches = 0.254 mm, so there will be rounding errors.

[katdoc]

If you have us version you can display the units in metric so whats the problem?

It's just more accurate/precise to use the adaptor if you intend to use metric units. Without the adapter, one tip = 0.01 inches = 0.254 mm, so there will be rounding errors.

understood! Thanks for all the info!

[katdoc]

Hi again

If i use the metric adapter to the us rain gauge should i choose also 0,01'' on the console or the 0,2 mm ??In the manual it says that you have to calibrate CAL to 0005 if you use the adapter.How about that?

[steve]

If you install the metric adapter, you have to tell the console that you have a metric (0.2 mm) rain gauge. I've never heard of that CAL setting before, sorry.

[prodata]

In the manual it says that you have to calibrate CAL to 0005 if you use the adapter.How about that?

Not in my Vue console manual it doesn't AFAICS! In which section of your manual are you reading that?

The only thing I can imagine that you're looking at is what's in the Calibration section. This is really intended for error correction, so if you're convinced that your Vue rain gauge is readings say 10% low then it's possible to apply an error correction (or 'calibration' if you will) of +10, for example. (Actually, it's not obvious to me how this works. Maybe in my example it will multiply the current number of tips by 1.1 and round to the nearest integer before re-storing the new integer value? But that doesn't really fly in the context of the archive record say, unless you've got a very high rain-rate and/or long archive interval. Perhaps it's only eg daily etc rainfall totals that are 'calibrated' by this process?)

But this has nothing directly to do with rainfall increment 'hard-coded' into each tipping spoon assembly.

[katdoc]

http://www.davisnet.com/product_documen ... _Rev_B.pdf

page 4: RAINFALL CALIBRATION NUMBER (check the note on page 5 )

[prodata]

page 4: RAINFALL CALIBRATION NUMBER (check the note on page 5 )

Ah, that's the 7852 rain gauge intended for use with the old WMII and Wizard stations, which did use calibration numbers. The instructions are nothing to do with the Vantage Pro 2 or Vue stations.

Actually, the tipping bucket mechanism is the same as on a VP2, but the way that the rain-clicks are processed by the VP2 console is somewhat different - there is no provision that I'm aware of for calibrating rainfall on the VP2 console.