measure low flow rate under low pressure
measure low flow rate under low pressure
(OP)
Is there an easy and effective way to measure low flow rate fo air(6-10gal/hour) under low pressure (1psi)?
This is calc of orifice size.
Thanks
This is calc of orifice size.
Thanks
It boils down to simple math.





RE: measure low flow rate under low pressure
You might also be able to calibrate a hot wire to air flow. The wire will cool faster in higher flows, so you can measure the current it takes to keep the wire at a given temperature and correlate that to air flow past the wire.
"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics
http://virtualpipeline.spaces.msn.com
RE: measure low flow rate under low pressure
Do you need a continuous measurement of the flow? How accurate? And does the output need to be electronic, and trended, or is a periodic observation OK? And do you need flowrate rather than (totalized) flow quantity?
If the flow is out of a system and can be collected at a single point, a wet test meter (positive displacement flowmeter) will do the job most accurately, with a stopwatch if you want average flowrate. Want it electronioc? Put an encoder on it.
Or you can do it by simple downward displacement of water.
If the flow is into a system through a single point, what's feasible depends on what you mean by low pressure. Is the system pressure low AND the air supply pressure low?
No need to make your own hotwire anemometer- there are plenty on the market. Better still for low flows, there are thermal mass flowmeters and controllers- if your upstream pressure is high enough for them. See Brooks, Porter, Aalborg, Bronkhorst etc.
RE: measure low flow rate under low pressure
"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics
http://virtualpipeline.spaces.msn.com
RE: measure low flow rate under low pressure
"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics
http://virtualpipeline.spaces.msn.com
RE: measure low flow rate under low pressure
RE: measure low flow rate under low pressure
Biginch:
The tubing outside is 3/8" and I could just feel a little flow by hand. The flow rate is needed for environmental analysis and do not have to be very accurate.
I thought of the same thing and tried to use a differential pressure gauge to catch the flow rate. But I do not know how to make the orifice.
moltenmetal:
I wish I can find something inline and plug&play. Thanks.
It boils down to simple math.
RE: measure low flow rate under low pressure
http://www.bubble-o-meter.com/
RE: measure low flow rate under low pressure
unclesyd,
great idea.
"If everything seems under control, you're just not moving fast enough."
- Mario Andretti- When asked about transient hydraulics
http://virtualpipeline.spaces.msn.com
RE: measure low flow rate under low pressure
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