Welcome to our site!

Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

  • Welcome to our site! Electro Tech is an online community (with over 170,000 members) who enjoy talking about and building electronic circuits, projects and gadgets. To participate you need to register. Registration is free. Click here to register now.

Electronic Disdrometer

Status
Not open for further replies.

Vizier87

Active Member
Hello guys, I'm designing a disdrometer for my weather station project. I'm currently using a piezo speaker mounted on a broken cd/dvd disc to increase it's sensitivity. When rain hits the surface, the transducer should give some output.

So the question: Is the LM2917 freq-to-voltage suitable to read the raindrop frequency?
If no,is there a way to 'latch' the output? So that, let's say a heavy raindrop gives 2.5 volts, and the frequency of it hitting the platform is 2 Hz, so that the output of the amplifier is not 'gated' but more of a 'damped' output. The Peak output will fall slowly with time' lets say 3 seconds, but it'll re-hit the peak after the next raindrop.
It'll be easier to translate it via an ADC.

Here's the link to a less defined project: https://www.instructables.com/id/Make-an-acoustic-rain-gauge-disdrometer/
 
Last edited:

jpanhalt

Well-Known Member
Most Helpful Member
The LM2917 is essentially an integrator. If each pulse is the same intensity and duration, then the output is proportional to frequency.

Will all rain drops, independent of size, make the same level of noise? What about sleet, snow, and hail? How are you going to resolve the situation when two or more drops hit the CD platter at roughly the same time?

I doubt any of us can say with certainty whether it will work or not, but there are obvious issues to consider.

You might consider as an alternative approach analysis of the sound. As an example, check out the freeware program called SoundRuler. That program is designed for analysis of bird calls. You can feed it a sound, identify a single call, and then the program will find and identify how many similar calls are in the analysis section. In your case, of course, a "call" is the sound of a single drop. Repeat sampling at, say, 4 sec intervals and you have your drop frequency. Further analysis of the sound may also help is assessing the size distribution too, not just the average volume over a period of time. There are other more sophisticated programs for sound analysis, but SoundRuler, while limited, is simple and will give you a feeling for whether that approach might work.

Sounds like a fun project.

John
 
Last edited:

jpanhalt

Well-Known Member
Most Helpful Member
I don't see how sending a signal to a PIC will compromise it. My view is pretty consistent with the "garbage in, garbage out" theory (GIGO). I would put my efforts upstream to get good data before worrying about its analysis.

John
 
Status
Not open for further replies.

Latest threads

EE World Online Articles

Loading
Top