Seeking Advice on Achieving Stable Hydrogen Flow Control with LabVIEW

[Mohaimin_95]

I'm currently using an Omega FMA-1618A flow meter to monitor hydrogen gas flow at approximately 250 sccm. However, I’ve noticed that the flow rate tends to drop over time. To maintain a steady flow at 250 sccm, I’m planning to implement a PID control loop in LabVIEW by integrating an automatic valve.

One option I’ve been considering is the VSO miniature proportional valve (I have attached the data sheet). However, I’m unsure how straightforward it is to integrate this valve with LabVIEW.

Could anyone offer guidance or share experience on the best way to approach this setup? I’ve attached a sketch outlining the issue for reference.

Thank you in advance for your help.

[Kyle97330]

I mean, the valve itself can't be directly controlled by LabVIEW.  It has no PC interface.

Look at the schematic on page 7 of its datasheet:

If you want to control this with LabVIEW, you will need "something" that provides that "Control voltage input" in the upper left that is usable with LabVIEW, plus implementing all that other stuff in the circuit properly.  There's hundreds of devices out there that could be controlled by LabVIEW that can output 0-5V DC.

Honestly though, I think you just want a dedicated device for this.  There are two types of flow "meter".  One is a "reads the flow" meter, which I think you have now.  The other is a "sets the flow and also reads it" meter, though this is probably better called a "flow controller".  Unless you have basically zero budget for this, I'd look for one of them instead.  This is one example, but I'm not specifically recommending that exact model, just the concept in general.

LabVIEW is great for creating custom solutions to integrating multiple pieces of test, measurement, and manufacturing equipment, but if there exists a single-component out-of-the-box solution, it's usually best to get that and not re-engineer it.

[AnalogKid2DigitalMan]

I second Kyle's recommendation of using a COTS dedicated device.

-AK2DM

[Quiztus2]

A bought one will be calibrated. That's what you want. I have experience with Swiss Vögtlin, but I wouldn't recommend those. Software and Support are meh.