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Figure 3. Calibration Percentage CalculationsCalculations Confluence- Calibr.

Initial Prep Guide:

1. Gather equipment needed
   1. Leak valve
   2. Wrenches 
   3. Nitrogen tubing line
   4. Relevant Hardware
2. Ensure Nitrogen Dewar is full, and/or is at least more than half full.
3. Close-off RGA section with its respective valve
   1. Leaving it under vacuum
4. Close-off turbo/roughing pump section with respective valve
   1. Leaving it under vacuum
5. Connect nitrogen line to inlet valve with pressure relief valve
   1. Allow approximately 5 minutes for system to be backfilled with nitrogen
6. Remove blank from RGA cart hose, and replace with leak valve (Reference Figure 2)
   1. Ensure nitrogen is flowing through the system before starting this step!
   2. Ensure leak valve is tightly closed before placing onto hose
7. Once leak valve is tightly sealed/connected to hose, let the system backfill with nitrogen again
   1. Make the connection to the leak valve at the end of the hose, making sure to tighten bolts all the way until metal to metal contact is made.
   2. Backfill for approx. 3-4 minutes
8. Close, and then remove nitrogen line from current position and relocate to it respective spot on the leak valve
   1. Ensuring the leak valve is tightly closed, so no nitrogen is flowing into the system
9. Turn on the roughing pump.
   1. Monitor the pressure at the roughing pump by observing the pressure at the Pirani gauge(s) as you throttle the valve(s) which open the roughing to the system. Do not open the valve to the RGA head!
10. If turbo and pump are separately operated
    1. Once the cart and hose pressure are below 10-2 torr, switch on the turbo pump and wait for pressure to reach a value below 10-7.
    2. If pressure will not go this low, it is likely there is a leak somewhere on the cart or on the new connection
11. Open the valve to the RGA head slowly while observing any pressure changes at the cold cathode.
    1. Pressure should equalize slowly. If pressure spikes, throttle the valve until the pressure equalizes. This would be an indication that the RGA was last vented (oops!).

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