Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On 03/05/17 11:05, Terry Coles wrote: As I mentioned at last night's meeting, we are currently considering a solution based on measuring the air pressure in a pipe that is connected to the bottom of the butt. In case you didn't already know, 'digital' versions of these are available quite easily and probably cheap, or free. They are used in most if not all washing machines and dish washers. The one I've looked at recently has a screw for pressure adjustment. You could get hold of at least two of them (one for "too high" and one for "too low") and connect them to GPIO pins if exact water height doesn't matter. If the problem is making sure the water is pumped from the lower tank to the header tank, but the pump is turned off when the header tank is full or the lower tank is empty then there's some quite simple ways to do that. But they don't require a computer so aren't perhaps technical enough for this list. :) Also, I wrote my last e-mail before I had looked at the Wimbourne Model Village web site. I imagined it would be indoors and a lot smaller than it is! -- Andrew. -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On Monday, 1 May 2017 12:26:09 BST Terry Coles wrote: > Has anyone ever done anything like this? Ideally, for level, an ultrasonic > sensor with a good level of water resistance would be ideal (it won't be > immersed, but it will be exposed to rain, mist etc). The capacitive sensor > requires RF, which brings it's own issues and the other types may provide > readings that are too coarse to monitor rate of change of level. > > I haven't found anything much yet that will give us flow measurement in a > 'river'. The commercial types tend to be fairly cheap but designed to go > into pipes. However, we should be able to come up with something using > hall effect sensors, so I'm more interested in level at the moment. > > Any ideas, links to projects that have done this? A quick update on this: As I mentioned at last night's meeting, we are currently considering a solution based on measuring the air pressure in a pipe that is connected to the bottom of the butt. Obviously when the tank is empty the sensor will measure 0 kPa (as compared to the atmosphere) and when it is full it will measure the pressure due to the height of the water column, which I calculate to be up to 15 kPa in a 200 litre butt. Also, someone on the Raspberry Pi Forums has suggested using a load cell to weigh the butts. I'm still looking at that. Both solutions are based on the 'strain gauge' type of sensor, so the output voltage tends to be rather low (typically less than 30 mV). This would require us to design some low noise circuits to amplify the signal to the level where it can be converted to digital for the Pi to process. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On Wednesday, 3 May 2017 10:55:36 BST Ralph Corderoy wrote: > > If you go to http://explorer.geowessex.com/ and enter the WMT's > > postcode (BH21 1DY), the map will show the Model Town. Then go to the > > Layers control, turn on Flooding; Floodzones 3 > > There's a `Share' icon in the right-hand side. I've been using this tool for years and never noticed that ;-) -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
Hi Terry, > If you go to http://explorer.geowessex.com/ and enter the WMT's > postcode (BH21 1DY), the map will show the Model Town. Then go to the > Layers control, turn on Flooding; Floodzones 3 There's a `Share' icon in the right-hand side. http://explorer.geowessex.com/?search=BH21%201DY=9865,41=27=400782.43=99823.41=27700=15 Cheers, Ralph. -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On Wednesday, 3 May 2017 08:08:37 BST PeterMerchant via dorset wrote: > On 02/05/17 22:18, Tim wrote: > > Could be interesting if the Rivers ever flooded Wimborne having to get > > the model village replicate the situation, sorry a bit OT there, just > > my warped humour coming out. > I think that it would automatically happen. The Model Village is > virtually on the flood plain by Wimborne. Actually it's not. If you go to http://explorer.geowessex.com/ and enter the WMT's postcode (BH21 1DY), the map will show the Model Town. Then go to the Layers control, turn on Flooding; Floodzones 3 and you will see that the flood plain goes round the Model Town. Even the 1 in 1000 year layer doesn't really touch it. The main floodzone follows the River Stour with much smaller floodzones around the River Allen. The model town only includes the two branches of the River Allen within its boundaries. -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On Tuesday, 2 May 2017 21:45:46 BST Andrew wrote: > It looks like the real rivers are being monitored in at least two places: > > https://www.riverlevels.uk/river-stour-oakley-wimborne > https://www.riverlevels.uk/river-allen-colehill-walford-mill > > As a model town I would be tempted to find out how they are doing that > level monitoring and then make a miniature version in the correct places > on the model. Unfortunately, neither of those places are within the are encompassed by the model town. Also, I suspect that the Environment Agency or whoever does the monitoring on the real rivers can afford to spend just a little bit more on their sensors than we can. > Is the monitoring just to control the river flow? Does it need to be > more complicated than a header tank and a valve for each river entry > point to control the flow rate? The monitoring has two functions. Fundamentally it is to control the level of water in the in the 'river' (and therefore the flow). In the past, the river has 'flooded' when there has been a lot of rain or when an over enthusiastic volunteer forgot to turn the tap off. The main goal though is water sustainability. We want to catch rainwater in the butts and then pump it in and out of the river automatically, hence the need for extensive monitoring. It has been pointed out that this project is a bit 'over-the-top' for a few tens of metres of water channel. However, when finished, the workings of the control system will be made available for visitors to view on a monitor; the idea being to enhance the education value of the attraction. > Once you collect the water at the end of the river it can then be pumped > up to the header tank until it is full. That is effectively what we have at the moment, except that there is a sump at the bottom of the river system and a bog garden at the top. Water is pumped manually from the sump to the bog garden and the whole thing topped up from time to time when water is lost due to leaks and evaporation. They have no way to combat flooding at present. > For extra complexity, get the water level of the real rivers from > wherever the above web site gets its data and adjust the levels of the > model rivers accordingly... Now you're pulling my leg :-) -- Terry Coles -- Next meeting: Bournemouth, Tuesday, 2017-06-06 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
Re: [Dorset] A New Wimborne Model Town Project Query - Sensing Water Levels and Flow
On 02/05/17 22:18, Tim wrote: On 02/05/17 21:45, Andrew wrote: Hi Terry, It looks like the real rivers are being monitored in at least two places: https://www.riverlevels.uk/river-stour-oakley-wimborne https://www.riverlevels.uk/river-allen-colehill-walford-mill As a model town I would be tempted to find out how they are doing that level monitoring and then make a miniature version in the correct places on the model. Is the monitoring just to control the river flow? Does it need to be more complicated than a header tank and a valve for each river entry point to control the flow rate? Once you collect the water at the end of the river it can then be pumped up to the header tank until it is full. For extra complexity, get the water level of the real rivers from wherever the above web site gets its data and adjust the levels of the model rivers accordingly... Could be interesting if the Rivers ever flooded Wimborne having to get the model village replicate the situation, sorry a bit OT there, just my warped humour coming out. Tim I think that it would automatically happen. The Model Village is virtually on the flood plain by Wimborne. Peter -- Next meeting: Bournemouth, Tuesday, 2017-05-02 20:00 Meets, Mailing list, IRC, LinkedIn, ... http://dorset.lug.org.uk/ New thread: mailto:dorset@mailman.lug.org.uk / CHECK IF YOU'RE REPLYING Reporting bugs well: http://goo.gl/4Xue / TO THE LIST OR THE AUTHOR
