Water flow data logging

[JRL]

I'd be keen to have the ability to record some water flow statistics at a cave site for a month or two.  Some recordings need taking underground (150 metres from the surface) and some recordings in a stream on the surface. I've got no experience with this type of thing so any help or advise appreciated. I'm not a computer geek and don't converse in binary.

I realise that more information may be required to assist, if so please get in touch.

Thanks, JRL

 

[TheBitterEnd]

This recent thread covered some of the issues.

Palmer (Cave Geology) has a section on flow measurement with a description of techniques on pages 102/103.

I'm not a computer geek and don't converse in binary.

I am and I am there or there abouts with this project http://interestingto.me.uk/Open%20Source/low-cost-low-power-datalogger which does pretty much what you need -i.e record data to an SD card.

Upshot - depending on timescales etc. I'd be interested in helping out.

 

[ian.p]

Hi JRL
Also happy to assist if i can what is it you are trying to achieve (feel free to PM if sensitive)? If you need money to buy equipment for a research project don't forget you can apply for a CSTRI grant from the British cave Research Association http://bcra.org.uk/detail/research-fund.html

 

[JRL]

Thanks for the replies, I'll be in touch with you both asap.

 

[Badlad]

A cheaper and less technical alternative might be to get one of the DCC to stand there with a note book;

Dry feet - less than a foot deep
Wet feet - more than a foot deep
Very small penis - more than three feet deep
No more notes - over six feet deep

 

[JRL]

Brilliant idea but one flaw in the plan.

The 'very small penis' box would be ticked 'yes' at every reading.

 

[Bottlebank]

JRL is an easy one, but that's got me wondering who Badlad is, a pint for the first person to PM me with the true identity 

 

[adep]

A cheaper and less technical alternative might be to get one of the DCC to stand there with a note book;

Dry feet - less than a foot deep
Wet feet - more than a foot deep
Very small penis - more than three feet deep
No more notes - over six feet deep

Surely everyone has a small penis when standing in deep cold water??, my balls are usually in my throat as well!!

 

[TheBitterEnd]

Whilst this thread seems to have wandered off topic a bit, I was just struck by the thought that the ultrasonic airflow detection discussed in this thread  - http://ukcaving.com/board/index.php?topic=16123.msg210729#msg210729
may be applied to water with suitable waterproofing and adjustment of the measurement parameters.

It would need a short length of fairly straight, regular shaped channel, but presumably that could be created with a pipe or scaffold boards if there is nothing suitable naturally...

 

[Bob Mehew]

It would need a short length of fairly straight, regular shaped channel, but presumably that could be created with a pipe or scaffold boards if there is nothing suitable naturally...

I thought the normal flow measurement technique is to create a V shaped weir and measure the height for good sized flows of water (that is at least 1 foot square cross section).  But see http://www.appropedia.org/How_to_measure_stream_flow_rate for other ideas.  I presume you want to have the data logged whilst you are not present which makes it a bit more difficult.  The BitterEnd's data logger seems ideal for doing that, so all you need is to sort out a measuring device. 

For reasonably deep simple sided channels, a float linked to a potentiometer can do the job simply provided it does not get washed away.  My memory of the maths of placing a channel within an existing channel is you are getting into very complex non linear behavior.  Simpler to channel the whole flow through a pipe with a propeller in it linked to a small motor and measure the power output.  Build a temporary dam using sand bags.

 

[bograt]

One suggestion bandied about by the micro-hydroelectric community is to use a known volume drum and time how long it takes to fill, taking this one step further, if a flopjack is fitted, a data-logger could be used to count the number of tips in a set time span.

 

[TheBitterEnd]

Yep, it was just an idle musing more than anything else. I would tend to go for a V notch or submerged weir but I can see a few disadvantages to those in a typical upland stream such as installation, filling up with rocks/gravel up stream, mounting a depth sensor etc.

The thought about the ultrasonic approach was that if there is a metre or two of channel with fairly uniform cross-section then installing a couple of sensors may be easier and less obtrusive.

Anyway, no more distractions... back to the other thing ... once I've finished the decorating

 

[Pitlamp]

Can you learn anything useful from the datalogging work going on currently in the Peak / Speedwell system? (See recent Speleology magazine for a teaser.)

 

[Pringletours]

1. Not 0


Sent from my iPhone using Tapatalk

 

[JRL]

Thanks all for your comments. Hopefully sorted now.

Cheers, Johnny

 

[TheBitterEnd]

Some of us are interested in this sort of thing, are you planning to write up your approach/results at some point?

 

[JRL]

Yes. ASAP!