Hello, I'm interested in measuring air (direction and mass (volume)) leaving a small (approximately 3 mm diameter) instrument vent tube during a rainfall event.
Is there a cost effective method to do this? ... I notice that there are commercial instruments like thermal mass flow meters that can do it, but they are quite expensive.
Any advice/ suggestions?
Thanks in advance.
Dear Michael,
1 ) Air Directions can be found out using Smoke tubes,
2) Volume can be measured by using soap bubble manometers.
Thanks
Regards
Manoj Bhagat
Thank you for the response Manoj,
The rainfall event may last (for example) 30 minutes or so, then we would like to monitor air flow for a further 30 minutes (or so) as the soil begins to drain.
I wonder how long does a smoke tube last? I suppose we could release a tube at say 5 minute intervals across the hour period to determine the overall pattern. However burning 12 tubes per experiment repeat could turn out expensive. .
Hi Mick,
I have no advice regarding your gas flow question :( but I really wanted to say hello and see how you are getting on. It sounds interseting waht you propose. Are you measuring soil microbe respiration? Coincidentally, I'm planning to measure methane flux of floodplain sediments in response to forest disturbance (thinning, flooding). If you have any references I could read let me know! Where are you living these days? I am living in Melbs with Kaili and 3 kids (all at high school now). WE are healthy and well. I'm working at Monash University on a forest understorey dynamics project (my field sites are only 2 hrs south of our old stompping ground at Wagga. I drop in to see Megan each xmas hols. SHe is doing some great research remote sensing vegetation condition. my email address is [email protected]. would be great to hear from you and good luck with your gas flux measurements :)
Cheers
Gillis
Hi Gillis, great to hear from you!
Yes lots of GHG soil sampling going on around the place (NSW DPI (Universities and other research bodies) have been doing it for decades) .. automated and manual chambers. I'm just a Techo doing the manual labour for a researcher, but I've done plenty of gas sampling.
I've just got an idea/ hunch and wanted to know if there was an inexpensive way to measure gas flow out (or in) from the chamber vent ..But as usual I've got no $$ ...
I think that there is no way round it but to acquire an expensive gas flow meter and data logger. Out of my jurisdiction.
I'll send you an email.
Mick.