WXforum.net
Weather Station Hardware => Hydreon RG-11 Optical Rain Gauge/Sensor => Topic started by: SLOweather on October 03, 2011, 12:25:45 PM
-
This is for discussion, installation, and operating tips and questions for the Hydreon RG-11 Optical Rain Sensor
(http://www.rainsensors.com/oe_images/rg_wht_bgnd_sm.jpg)
-
Does this unit connect to a read out box or a computer?
Tim
-
Does this unit connect to a read out box or a computer?
Tim
It's a bit more complicated than that. If by read-out box you mean a counter, then yes, that is one way it can be used.
You can read about it at http://www.rainsensors.com/ (http://www.rainsensors.com/) and download the manual PDF at http://www.rainsensors.com/docs/rg-11_instructions.pdf (http://www.rainsensors.com/docs/rg-11_instructions.pdf).
It has a single SPDT relay output, and several different modes.
* Tipping Bucket Emulation-- Replace your tipping bucket with a low maintenance alternative.
* "It's Raining"-- Close a skylight at the first sign of rain, and open it when it stops raining.
* Condensation / Frost Sensing
* Wiper control
* Irrigation Control-- No more watering during a downpour!
* Drop Detection
As a rain gauge it can be set for several different modes, like 0.01", 0.001", or even 0.0001" (and similar metric modes). However, even in 0.01" mode it's not as accurate as a tipping bucket, let alone a manual gauge.
There's a older thread about it at http://www.wxforum.net/index.php?topic=12273.0 (http://www.wxforum.net/index.php?topic=12273.0) if you want to read more.
-
Got one here too - must get round to setting it up (good intentions and all that, but last few weeks here have been seriously busy).
But I will aim to set it up at a site where there are good manual rainfall measurements being made (as well as Davis ones). So it will be an interesting comparison over the coming months.
-
I wonder if Davis is investigating these devices as an alternative to their leaf moisture sensors? These could actually provide some estimate of the amount of dew or frost on leaves instead of the unitless measurement number the current leaf sensors output. They of course would have to modify the leaf/soil stations to accept these or offer a special auxiliary station just to measure rainfall/moisture with them.
-
I wonder if Davis is investigating these devices as an alternative to their leaf moisture sensors? These could actually provide some estimate of the amount of dew or frost on leaves instead of the unitless measurement number the current leaf sensors output. They of course would have to modify the leaf/soil stations to accept these or offer a special auxiliary station just to measure rainfall/moisture with them.
I doubt it. The RG-11 requires 50 ma of AC or DC power, and the only output is a relay closure. It would take a major hardware and firmware rework to implement one of these on a VP system.
-
...and the only output is a relay closure.
Do you think it actually is a relay closure? I know the documentation says that but it just strikes me as a bit odd that someone would use a mechanical relay these days rather than a solid-state equivalent, eg a thyristor/triac or whatever they might be called now. The quoted max voltage seems somewhat low (24v) for relay contacts.
But same difference I know - equivalent to a contact closure.
-
Do you think it actually is a relay closure? I know the documentation says that but it just strikes me as a bit odd that someone would use a mechanical relay these days rather than a solid-state equivalent, eg a thyristor/triac or whatever they might be called now. The quoted max voltage seems somewhat low (24v) for relay contacts.
But same difference I know - equivalent to a contact closure.
Oh, yeah, it's a relay.
1) If you open your unit up, you will see it on the underside of the board.
2) If you do nothing more then power up your unit with 12 VDC in the stock 0.01" rain gauge mode, and spray a little water on the dome, you will hear/feel the relay click for every hundredth of an inch it senses. A the same time, the green activity LED in the center of the top of the board will light up.
-
Oh, yeah, it's a relay.
OK thanks - interesting. Just slightly surprised - I'd have guessed that the solid state part would do the same job, was cheaper than a mechanical relay, used less power, had a quicker response time and was more reliable. And Davis have been using the solid state part in the Alarm logger ever since it was introduced (5-6 years?). Guess there must be some design reason for Hydreon using the mechanical part but I can't immediately think what.
-
Guess there must be some design reason for Hydreon using the mechanical part but I can't immediately think what.
Relays are immune to bad hook ups, polarity issues etc.