Roberto,Roberto Ferrari wrote: ↑Mon Jan 22, 2018 4:47 pm Hi Jerry
Good point, thanks!
That one is 100 torr but we have also 10 torr FS.
We will manage to put an elbow or swap positions with the viewport, now at cross lower port.
Please be aware,that the 10 torr FS unit puts out 1mV per Micron of pressure, so that you are at the very far edge of the transducers usefull range.
With fusor pressures around 10-50 Micron, You will be measuring from 10-50mV, not a lot in a noisy environment. A better choice would be a 0.1torr unit, or even a 0.05 torr unit.
With a full scale output of 10V, the latter will still produce a full one volt at 5 Microns, and as such deliver a better resolution.
Another benefit of having a transducer with a FS close to the fusing pressure is, that it is able to deliver useful output at a couple of decades higher vacuum, prior to letting the deuterium into the fusor, the 10 torr unit will "bottom out" long before that.
In short, with a 10 torr unit, you will miss most of the action you get from the diff. or turbo pump, since it's output has fallen to 1mV at a pressure of 1 Micron.
Just some thoughts I did before choosing my Baratrons, both 0.05 torr FS. (One of which, by the way, clearly is marked, that it must be mounted horizontally to read correctly, go figure)
Cheers, Finn Hammer