Cumulus Support

Hi,

We have a Vantage Vue with a US rain gauge. That means one tip = 0.01 inch. But we set the console to Metric and I am getting the feeling that then one tip = 0.2mm not 0.254. Cumulus rain count seem to go up by increment of 0.2mm. Is Cumulus counting the number of tips? then for sure we are being shorted

I am confused because the console is giving us the same amount of rain as Cumulus and that would mean that even the station is shorting us.

I realize we can buy a metric rain collector but dont understand the point. Isn't it just a simple calculatiion to get metric reading from a imperial gauge ?

thanks for your input

Yvan

If that is indeed the case, it is simple to correct with a rainfall multiplier under configuration/calibration.

or recalibrate the gauge to 0.2 by adjusting the stop screws and dropping a known amount of water through it.

You can set the console and Cumulus to metric rain units even if you have an imperial rain gauge, but you have to tell the console that you have an imperial rain gauge - this is a separate setting; you probably already have this set correctly, it's the default. The console will then convert the 0.01" tips from imperial to metric (rounding to the nearest 0.1mm). But ideally, if you want to display metric, you would fit the supplied metric adapter to the rain gauge and tell the console that you have a metric gauge. Then each tip is 0.2mm and you have no rounding errors.

That sounds a better solution!

steve wrote:You can set the console and Cumulus to metric rain units even if you have an imperial rain gauge, but you have to tell the console that you have an imperial rain gauge - this is a separate setting; you probably already have this set correctly, it's the default. The console will then convert the 0.01" tips from imperial to metric (rounding to the nearest 0.1mm). But ideally, if you want to display metric, you would fit the supplied metric adapter to the rain gauge and tell the console that you have a metric gauge. Then each tip is 0.2mm and you have no rounding errors.

talk about someone who knows his stuff. Thanks Steve.

but then why Cumulus shows rain amount in increment of 0.2mm instead of 0.25. In other words, after three tipping Cumulus shows 0.6 not 0.75?

Yvan

rayauger wrote:but then why Cumulus shows rain amount in increment of 0.2mm instead of 0.25. In other words, after three tipping Cumulus shows 0.6 not 0.75?

Cumulus rounds rain to 1 dp if you have metric (mm) selected. I'm thinking of changing this so that the user has complete control over the number of dps displayed for each item. But the station is already rounding to 1 dp in this case, so it wouldn't make any difference.

steve wrote:................... But ideally, if you want to display metric, you would fit the supplied metric adapter to the rain gauge and tell the console that you have a metric gauge. Then each tip is 0.2mm and you have no rounding errors.

IIRC one has to purchase the metric adapter separately? There is no mention of swapping these cartridges in the Vue ISS manual but does mention it as an alternative in the specifications.

Metric rain cartridge, Part No. 7345.319

whitenemesis wrote:IIRC one has to purchase the metric adapter separately? There is no mention of swapping these cartridges in the Vue ISS manual but does mention it as an alternative in the specifications.

The adapter is supplied with the VP2 (my VP2 certainly had one, and I've never heard of anyone not being supplied with one.). In my ISS manual, the procedure is described at length on pages 14 and 15, in a section "Optional: Insert the Metric Measurement Adapter", and step 1 is "Find the metric adapter included in the hardware".

From what you say it is not supplied with the Vue, which is surprising.

Having Googled, I see that the Vue comes in two versions, one which operates on US radio frequencies and has an imperial rain gauge, and another which operates on frequencies legal outside the US (as you would expect) and has a metric rain gauge. The gauge cannot be converted - the 7345.319 spare part is apparently a replacement mechanism for gauges which are already metric.

Apologies for my misinformation, I wrongly assumed the Vue would be the same as the VP2 in this respect.

steve wrote:Having Googled, I see that the Vue comes in two versions, one which operates on US radio frequencies and has an imperial rain gauge, and another which operates on frequencies legal outside the US (as you would expect) and has a metric rain gauge. The gauge cannot be converted - the 7345.319 spare part is apparently a replacement mechanism for gauges which are already metric.

Apologies for my misinformation, I wrongly assumed the Vue would be the same as the VP2 in this respect.

I can confirm that. Most vendors in North America offer both models as shown in Davis website. Radio frequency looks to be the same though.

From Davis:

Available in two versions:
US (United States): US version uses US radio frequency from 902 to 928 MHz (on units equipped with wireless transmission) and a 0.01" rain collector. Station reports in US standard units. Includes US power adapter.
USM (United States, metric): US/Metric version uses US radio frequency from 902 to 928 MHz (on units equipped with wireless transmission) and a 0.2mm rain collector. Station reports in Metric units. Includes US power adapter.

rayauger wrote:I can confirm that. Most vendors in North America offer both models as shown in Davis website. Radio frequency looks to be the same though.

Ah, right. That must be (at least) three different models, then: US imperial, US metric, and non-US metric. Perhaps there's also a non-US imperial to make the full set.

Steve, I made the same assumption and almost posted along those lines

But having checked the VUE ISS manual I saw the rain gauge is modular and fitted during set-up. As such it has got to be worth $15 to try replacing with the metric part?

So, the Imperial rain data displayed on my Vue console, is in fact based on metric readings from my UK spec Vue ISS?

Have I got that right?

Sunfish wrote:So, the Imperial rain data displayed on my Vue console, is in fact based on metric readings from my UK spec Vue ISS?

Have I got that right?

That would seem to be the case, yes.