I'm trying to decide on a vacuum pump set up and have come up with two candidates based on their compression ratios for H2:
Adixen ATH31+. 1E11 N2, 1E5 H2 Compression Ratio
Aprox Prices:about $4,700 pump, about $1,700 controller, about $600 required accessories. 4 1/2" CF High Vacuum connection.
Pfeiffer TMU 071YP >1E11 N2, 1E5 H2 Compression Ratio
Aprox Pricesabout $5,200 pump, about $1,300 controller. 4 1/2" CF High Vacuum connection.
|ATH 31+||14||1e5||5e-10||2.7||4.5" CF||KF16||45||1||$4,700||$1700|
l/s = Pump Speed in liters per second For H2
CR = Compression Ratio H2
TU = Ultimate pressure in mbar
Wt = weight lbs
IF = Input (High Vacuum) Flange
OF = Output (Fore Pump) Flange
FP = Max Foreline Pressure mbar
FPS = Min Foreline Pump Speed m^3/hr
$Pmp = Cost of the Pump
$Cnt = Cost of the Controller
The Pfeiffer looks like a better pump for the money. A lot will depend on the fore pump. I'm leaning to a roots blower or some other oil less type pump. So let us look at some. First some education: Scroll vs Rotary Lobe Pumps.
IDP-3, technical [pdf], dry scroll, 3 m3/hr rate, 2.5e-1 torr. ultimate, $2,650
ACP15, technical [pdf], rotary lobe, 14 m3/hr rate, 3.8e-2 torr. ultimate, $5,134
1 torr = 1.33 mbar