Ping h2o

rulen

Is there any info as to when we can expect the PING H2O weatherproof sensor to hit the streets? It was featured in the Parallax 2010 calender but here we are almost half way through the year and it seems to have vanished. I am trying to record river heights with an ordinary ping, and although the sensor is well shielded from direct rain, it does not like misty mornings or the humidity associated with heavy rain. Needless to say, when it is raining is when the river is likely to rise, so my current situation is distinctly sub-optimal.

Thanks in advance,
Nick

Shawn Lowe

Nick-
Parallax ran into engineering problems with the Ping H2O. They may not be making them at all is the last I heard on it.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Shawn Lowe


When all else fails.....procrastinate!

rulen

Thanks. What a pity - you can not help liking the Ping - apart from this weather sensitivity it does exactly want it says on the tin!
I have tried covering bits of mine with liquid electrical tape, but I'm guessing there is something humidity sensitive where I did not dare go, ie close to the transducers.
Nick

kwinn

rulen, if power (120VAC) is available you could try heating the sensor enclosure to mitigate the effect of moisture. You may want to try another approach to measuring the river height if that does not work.

The simplest is a capacitive sensor consisting of 2 parallel conductive strips or a 1/2 inch copper pipe inserted in a 3/4 inch pipe. Both setups need spacers to hold things in place without blocking water access, but that is relatively simple. Add a resistor and measure the RC time constant to read water height. The only difficulty may be sediment fouling, but there are ways to avoid that.

The float from a new style toilet filler (float goes around inlet pipe) and a PVC pipe for a post might also work. Magnetic reed switches, optical encoder, multiturn pot, or a combination of reed switch and encoder could be used. More complicated than the capacitive approach or what you have now, but it has been proven in use.

rulen

Thanks; if the PING H2O really is no more I will have to bite the bullet - either another brand weather resistant sensor or the capacitive route sounds like the way forward. I'm also wondering if the IR range sensors work off water surfaces.
Nick

kwinn

Even if the IR range sensor does not work off the water surface you could have a captive reflector of some kind floating on the water. In my case I was measuring the height of water in a tank for a well system and found the capacitive method simple and reliable. The outer pipe was 3/4" copper, the inner pipe 1/2" copper, and holes were drilled through the inner pipe every 12" for the nylon screws that were used as spacers. A little bit of sanding of the screw heads was required for a snug fit.

rulen

Thanks, your post is very encouraging. I guess I do not rank my skills very highly, and am nervous of:
1) the need to calibrate (but I could use the PING on a dry day)
2) whether the capacitance changes according to sediment in the water
3) whether I need to periodically reverse the current to prevent electrolysis
In some seasons my river will actually deposit calcium on leaves on low hanging branches, so I am wary of changing chemistry in the water.


Nick

Shawn Lowe

Have you seen these:

http://www.parallax.com/Store/Sensors/PressureFlexRPM/tabid/177/CategoryID/52/List/0/SortField/0/Level/a/ProductID/590/Default.aspx

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Shawn Lowe


When all else fails.....procrastinate!

rulen

Good point. Its far from ideal (I really need to cover a range of about 70cms, and at a lesser accuracy about 3m), but it may be my simplest and most reliable option for the crucial range where flooding might occur.
Many thanks once again,
Nick

John R.

Nick;

You might want to contact the manufacturer of the sensors Shawn pointed out. I have not talked with them, but their web site talks about other lenghts, and somewhere even mentioned "continuous tape" to "cut your own length.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
John R.
Click here to see my Nomad Build Log

Tracy Allen

Maybe this?
maxbotix.com/MB7060__XL-MaxSonar-WR1.html

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Tracy Allen
www.emesystems.com

Thomas Bauer

rulen said...
Thanks; if the PING H2O really is no more I will have to bite the bullet - either another brand weather resistant sensor or the capacitive route sounds like the way forward. I'm also wondering if the IR range sensors work off water surfaces.
Nick

Hi Rulen,
The Ping H2O project is still lurking in the background of my to-do list. The project is not dead and I do plan on reviving it here in the very near future. A complete redesign is required and the newer version promises to be very exciting. I will give more details as the project progresses.

Thomas

rulen

My thanks to all who have helped me with this thread, I really appreciate your ideas. Thomas, if you ever need a beta tester (or even an alpha), just let me know.
Nick

Shawn Lowe

Thomas Bauer (Parallax) said...

rulen said...
Thanks; if the PING H2O really is no more I will have to bite the bullet - either another brand weather resistant sensor or the capacitive route sounds like the way forward. I'm also wondering if the IR range sensors work off water surfaces.
Nick

Hi Rulen,
The Ping H2O project is still lurking in the background of my to-do list. The project is not dead and I do plan on reviving it here in the very near future. A complete redesign is required and the newer version promises to be very exciting. I will give more details as the project progresses.

Thomas

Ahh, very good. I was not sure, but its sound like this will be a hot seller; given the number of inquires i've seen.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Shawn Lowe


When all else fails.....procrastinate!