Hi, I will be measuring the flow rate at the device's outlet in any case. I would have done that even if I had a suitable mass flow controller, in order to calibrate it with retards to the outgoing gas. m On 10/11/10, Brian Stahlwrote: > Full disclosure: my experience with peristaltic pumps is limited to > low-viscosity liquids. Peristaltic pumps will create a pulsatile flow, > which may be important depending on application specifics. The factors I > see as being most important are the back pressure at the pump outlet and the > inlet pressure from your gas source. Peristaltic pumps can generate > significant output pressures (depending on the working fluid). If your gas > source is a pressurized cylinder with a regulator and your pump inlet > pressure is different from the outlet pressure you will have to do a > conversion to find the outlet volumetric flow rate. But I am not aware of > any thermodynamic reasons why you can't pump a gas with a peristaltic pump, > and your gas selection should only be limited by the type of tubing you use. > I hope this helps (or at least doesn't cause further confusion). > > Best regards, > > Brian C. Stahl