Rain Detector
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From: Paul Keinanen on 27 May 2006 11:36 On Sat, 27 May 2006 13:21:31 -0000, Grant Edwards <grante(a)visi.com> wrote: >On 2006-05-27, Leon <leon.heller(a)bulldoghome.com> wrote: >> An interesting technique is to count the impacts from raindrops in a >> given area, using a suitable transducer. It can be quite accurate, >> apparently. > >Do also have to measure the impacts to get an estimate of drop >size? You would have to apply the Marshall-Palmer-law and the Laws-Parsons-distribution to get a better relation between how much is raining and the drop size distribution. Paul
From: Paul Keinanen on 27 May 2006 11:36 On Fri, 26 May 2006 13:38:36 +0100, "Peter" <meltyb(a)hotmail.com> wrote: >"scilent-project" <Triblesix(a)gmail.com> wrote in message >news:1148642231.507115.158470(a)j33g2000cwa.googlegroups.com... >> Hi >> For final year project,I want to design a rain measurement device which >Pulsed microwave radar between 1 and 10cm is quite good for detecting rain >as it falls. The 10 cm (3 GHz) wavelength might be usable for detecting huge hails, but even a heavy (150 mm/h) rain will attenuate the 3 GHz signal with only 0.1 dB/km, so I very much doubt that you would get any usable reflections from the raindrops. Frequencies between 10 GHz (3 cm) and 100 GHz (3 mm) would be more suitable, although it might be hard to separate between drizzle and fog at the higher frequencies. Paul
From: Steve on 28 May 2006 07:11 On Fri, 26 May 2006 14:43:47 +0100, "Tom Lucas" <news(a)REMOVEautoTOflameREPLY.clara.co.uk> wrote: >As for the detection, the water level detection in the Industrial Boiler >Control I'm working on uses capacitance probes and is pretty sensitive. They >work by using an oscillator whose frequency varies with the capacitance of a >probe dipped in the water. Measure the frequency - know the depth. Picking up on this point - I'm interested in making an accurate aquarium level detector at the moment (saltwater) , and wonder how good this method could be. In an ideal world something like 1 mm resolution would be good. Could this method achieve this. Any suggestions on the general type of oscillator and ballpark frequency that might work best? Steve
From: John B on 28 May 2006 19:00 scilent-project scrobe on the papyrus: > Hi > For final year project,I want to design a rain measurement device > which can be read through parelle port of a PC. > All ideas on this topic are cordially welcome. > > thanks in advance. No, it seems from your post that you want the good folk here to design it for you, so that you can take the credit. Go away and design something, then come back here when it doesn't work. -- John B
From: John B on 28 May 2006 19:08
Oscar scrobe on the papyrus: .. > better one. Conductivity through collected water and periodic cup > dumping are common. Ah, the Chinese water clock. -- John B |