Instruction manual

19
VHS-4, VHS-6 and VHS-250 Diffusion Pumps
D R A F T 6 / 1 8 / 1 3
Section 1. Introduction and Installation
1.1 Introduction
Before unpacking and installing a VHS-4, VHS-6 or VHS-250 diffusion pump, thoroughly
familiarize yourself with this instruction manual and the diffusion pump operational
specifications (Table 1-1). Examine all other technical material supplied in order to gain a
better understanding of the operating principles, limitations, correct application, and
hazards involved with the operation of this equipment.
1.1.1 Pump Specifications
Table 1-1 lists the specifications for the VHS-4, VHS-6 and VHS-250 pumps.
Table 1-1 Pump Operational Specifications
Power Rating VHS-4: 1450 Watts
VHS-6: 2200 Watts
VHS-250: 2200 Watts
Optimum Operating Range (Torr) VHS-4 and VHS-6: 1x10
−3
to < 5x10
−9
(1.3 x 10
-3
to < 6.6 x 10
-9
mbars)
VHS-250: 7x10
−4
to < 5x10
−9
(9 x 10
-4
to < 6 x 10
-9
mbars)
Maximum Pumping Speed (l/s) VHS-4: Air – 1200 with std cold cap; 950 with extended cold
cap
Helium –1500 with std cold cap; 1200 with extended
cold cap
VHS-6: Air – 2400 with std cold cap; 1600 with extended cold
cap
Helium –3000 with std cold cap; 2000 with extended
cold cap
VHS-250: Air – 3700 with std cold cap; Helium –4600
Maximum Throughput (Torr-l/s) VHS-4: 1.2 (1.6 mbar-l/s) in operating range
2.5 (3.2 mbar-l/s) @0.01 Torr
VHS-6: 2.4 (3.2 mbar-l/s) in operating range
3.5 (4.5 mbar-l/s) @0.01 Torr
VHS-250: 2.6 (3.5 mbar-l/s) in operating range
3.5 (4.5 mbar-l/s) @0.01 Torr
Maximum Forepressure No Load – 0.65 Torr (.87 mbars)
Full Load – 0.55 Torr (.73 mbars)