H.P. 5988/5989 Probe Inlet Port with Automatic Stops

Description

Eliminates the accidental venting of the mass spectrometer via the probe inlet

• Complete Probe Inlet includes
  • Probe Isolation Valve Assembly
  • Probe Sealing Port Assembly
  • Mass Spec Mounting Bracket
  • Probe Guide Bar with Auto-Stop
• Mounts Directly to the HP Probe Inlet Port
• Three Automatic-Quick Release Positions
  • Ready or Load Position
  • First Vacuum Seal
  • Second Seal
• Easy Push-Pin Stop with Quick Release
• Adapts to all manufacturers 1/2 inch Diameter Probes

This new Probe Inlet System for the H.P. 5988 and 5989 mass spectrometers has been designed to prevent the occasional venting of the mass spectrometer by accidentally pulling the probe past the vacuum seals. The inlet system mounts to the probe inlet port on the H.P. mass spectrometers via the standard O-Ring sealing system supplied with the mass spectrometer.

The Probe Inlet System consists of -

• The Probe Isolation Valve Assembly & Mount
• The Probe Sealing Port Assembly
• The Guide Bar and Auto-Stop Assembly

The S.I.S. Probe Valve Assembly & Mount comes complete with all seals to permit the delivery of the 1/2 inch diameter probe rod through the valve and into the mass spectrometer. The assembly mounts directly on the mass spectrometer flange and is sealed via the O ring seal on the mass spectrometer manifold.

The Probe Sealing Port Assembly includes the redesigned PTFE probe rod seals, pump out valve and a 4ft length of Tygon vacuum tubing to connect the valve to the mass spectrometer vacuum pump. It mounts to the Probe Isolation Valve Assembly using an O-ring and clamp system. The probe sealing port assembly uses a new PTFE sealing system designed by S.I.S. which provides for much better vacuum sealing of the probe rod as well as longer life. The original vacuum seals on the probe inlet supplied by H.P. are an encapsulated O Ring and two inner spring seals. Our newly designed PTFE seals are far superior. They utilize a large PTFE sealing surface which provides for a cleaner system with longer seal life and superior vacuum sealing.

The Guide Bar and Auto-Stop Assembly is mounted directly onto the Probe Inlet Valve Assembly. Any 1/2 inch diameter probe can be clamped onto the guide bar assembly. The probe can then be pushed into the vacuum sealing system and valving system with automatic stops at the load position and at the two vacuum seals. This will prevent pushing the probe in too far during initial insertion damaging the probe tip and also prevent inadvertently pulling the probe out too far and venting the mass spec during probe removal. A quick release push button on the probe guide bar releases the probe for travel to the next position. The Probe Inlet System is designed for use with all direct probes, DEP (DCI) probes, FAB probes and other 1/2 inch diameter probes from S.I.S. and H.P.

SIS Probe Inlet vs HP Probe Inlet Study

The chart in the upper left shows the results from a study which was conducted at SIS comparing the HP probe inlet system to the SIS inlet system. The SIS probe inlet system was mounted onto an automatic probe injection system which was fitted to a vacuum chamber where the vacuum was measured with a ionization gauge tube. The vacuum in the chamber was measured after each injection of the probe through the probe inlet. This allowed us to monitor the vacuum levels as the seals in the probe inlet began to wear from repeated use. The probe inlet system was considered to have failed when the ionization gauge would not remain on (i.e. the vacuum was greater than 1x 10 -4 torr). As can be seen from the chart the SIS probe inlet system provided satisfactory performance for over 2500 injections of the probe until it failed at injection number 2649. The HP probe inlet was then mounted onto the automatic probe injector and the test repeated. The HP probe inlet first failed at injection number 14. The inlet was removed and inspected. There were fine pieces of graphite throughout the probe inlet. The probe inlet was cleaned, the same exact seals re-inserted and the inlet was remounted to the automatic injector. The test procedure was continued. The probe inlet failed again at injection number 29. The cleaning procedure was done a second time and the test continued. This failure and cleaning process was repeated seven times until the probe inlet failed completely at injection number 290.