wanted: continuous duty, low volume air pump

Client needs a dozen air sampling pumps, low volume, continuous duty, to move air from a laboratory to an RH sensor through 2 meters of flexible tubing (which mandates a threaded fitting or hose barb for tubing).

Lots of battery powered pumps intended for personal protection air sampling, but not really designed for continuous duty nor easily powered by 115Vac or a power supply.

Aquarium pumps are cheap and continuous duty (yeah, I know, they need frequent replacement) but lack a sample hose barb for the pump input.

Any suggestions?

I ran into a similar need some years back

The inexpensive aquarium pumps were put into inexpensive plastic boxes with a hose barb epoxied on to the side wall.

At less than $25 a pop, it satisfied the need. Looked OK,

A fish pump with a hose barb inlet would have been perfect, but I'm sure such a configuration would be a warrantee nightmare for the makers as the aquarium hobbyists would be sure to put a hose on the fitting and throw the other end into the water. Then wonder why no bubbles were to be seen.

thanks for the advice and the links. Dan

danw said:

Client needs a dozen air sampling pumps, low volume, continuous duty, to move air from a laboratory to an RH sensor through 2 meters of flexible tubing (which mandates a threaded fitting or hose barb for tubing).

Lots of battery powered pumps intended for personal protection air sampling, but not really designed for continuous duty nor easily powered by 115Vac or a power supply.

Aquarium pumps are cheap and continuous duty (yeah, I know, they need frequent replacement) but lack a sample hose barb for the pump input.

Any suggestions?

Click to expand...

Gast would be the first place I would look. May need to put a bypass valve in at the instrument end but this may not be so bad an idea - would give sample short transport time and avoid any condensation problems in the line.

Dan Bentler

Try Thomas Industries division of Gardner Denver.

They do exist i have several here running for CO2 metering.
another way is to box your pump inside an airtight box and put a small hose on the outlet to open air.
put the sensor before the pump.
i also use simple solenoid valves to control up to 10 storage holds on commercial ships)
CO2 is easy, RH is very temperature dependent and needs more
like pressure, temperature and yes the RH.
most RH meters are above 5% so dont worry too much.
i think you are better of with in every room a R and temp sensor.
or a dry and wet bulb temp sensor.
We have both types running, the dry/wet are cheap and will always work, the chemical RH sensors tend to deflect within a year, and do have problems with contamination.