[James98]

The level of suction is important but it’s not as important as a sensor.

I have not seen a pump advertised as having a sensor. BB pumps have settings, but it just changes the number of seconds it pumps before releasing.

I have been working on building one, and it turns out to not be as easy as I thought. I had hoped to sell them for $300, but now I think I will have to charge significantly more. Main problem has been to reduce sensor noise, that is the reading bounces  around too much and it takes careful design to make it stable and accurate. Currently varies about +/-1kPa which is probably good enough.