For a number of years I have used navel oranges as floats in the velocity-area method. Oranges are better than the many other citrus like tangeloes manderins lemons etc. they need to be solid enough to have a density close to water. Take six-eight even-sized fruit, and have a stopwatch with a lap-timer. Float all the oranges at one time down the stream over the set distance (often in my case 5-10 metres) and record the 'lap' time of each one as it goes through the 'finish line'. Record these lap times on paper as individual times. I start this process by placing all the fruit into a plastic bag, and then placing this into the water as a type of control starting gate if you like. I simply have the top of the bag clinched shut at the surface and make sure all oranges are floating within, then pull the bag down into the water away from the oranges. Do this any number of times and you have a range of times from which to take an average. Some of the oranges will be slow due to eddies, backwashes and such like but from the range of times these outliers become obvious. After a few timed runs the oranges will be nice and cool for a stream side snack too. Oranges are good floats because they submerge to within a skins thickness of the water surface and so 'float' within the flow, not float on top of it.
Any good manual on hydrology monitoring methods will have some derivative on the salt dilution technique. Many of the streams I have monitored have been suitable for this method as well, but for the list of equipment required it is a good way to do it as well. I didn't like the thought of introducing a salt to the water either. I prefer the simple ways. Regards, Phil ----- Original Message ----- From: "Steven Schoeffler" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Saturday, January 29, 2005 11:27 AM Subject: Re: [microhydro] Measuring stream flow > > > Salt dilution method? Where does one learn about such things? Is there a > good reference that teaches everything about microhydro? > > Thanks. > > Steve > > ----- Original Message ----- > From: Carlos Bonifetti > To: [email protected] > Sent: Friday, January 28, 2005 3:11 PM > Subject: Re: [microhydro] Measuring stream flow > > > > Hi Brendan, Steve, ....: > > For that flow, the salt dilution or current velocity/area measurement > with > floating devices methods are both practical. > > Regards, > > Carlos > > > ----- Original Message ----- > From: "Steven Schoeffler" <[EMAIL PROTECTED]> > To: <[email protected]> > Sent: Friday, January 28, 2005 3:58 PM > Subject: Re: [microhydro] Measuring stream flow > > > > > > > > Please respond to the group.... I'd be interested in this also. > > > > Thanks, > > > > Steve > > > > ----- Original Message ----- > > From: B Fitzgerald > > To: [email protected] > > Sent: Friday, January 28, 2005 8:55 AM > > Subject: [microhydro] Measuring stream flow > > > > > > > > > > Hello Microhydro group, > > I am looking to measure accurately the flow in a stream that I am > > interested in developing. Using the flow prediction by area-rainfall > > method I have calculated that the provisional mean flow is > > approximately 0.25 cubic metres per second. I have investigated a > > number of methods and have decided that a dilution method or a > > velocity-area method utilising a propellor current meter or > > electro-magnetic current meter would be most suitable. (The weir > > method or bucket fill method are not possible in this situation). > > I would like to know if anyone has any information or is selling a > > reliable current meter or indeed if anyone had any tips on evaluating > > the flow of a stream. I will be taking measurements at regular > > intervals over the next 7 to 8 months. > > Thank you all for your time, > > > > Regards, > > Brendan Fitzgerald > > IT Tralee > > > > [Non-text portions of this message have been removed] > > > > > > > > Does your company feature in the microhydro business directory at > http://microhydropower.net/directory ? If not, please register free of > charge and be exposed to the microhydro community world wide! > > NOTE: The advertisements in this email are added by Yahoogroups who > provides us with free email group services. The microhydro-group does not > endorse products or support the advertisements in any way. > > More information on micro hydropower at http://microhydropower.net > > To unsubscribe: send empty message to > [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > > ------------------------ Yahoo! Groups Sponsor --------------------~--> In low income neighborhoods, 84% do not own computers. At Network for Good, help bridge the Digital Divide! http://us.click.yahoo.com/EA3HyD/3MnJAA/79vVAA/FGYolB/TM --------------------------------------------------------------------~-> Does your company feature in the microhydro business directory at http://microhydropower.net/directory ? If not, please register free of charge and be exposed to the microhydro community world wide! NOTE: The advertisements in this email are added by Yahoogroups who provides us with free email group services. The microhydro-group does not endorse products or support the advertisements in any way. More information on micro hydropower at http://microhydropower.net To unsubscribe: send empty message to [EMAIL PROTECTED] Yahoo! Groups Links <*> To visit your group on the web, go to: http://groups.yahoo.com/group/microhydro/ <*> To unsubscribe from this group, send an email to: [EMAIL PROTECTED] <*> Your use of Yahoo! Groups is subject to: http://docs.yahoo.com/info/terms/
