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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. If cart 2: Turn off Turbo, leave roughing pump on
   2. Leaving that section 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+turbo. (Do not open the valve to the RGA head YET!)
   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.
   2. Pump for approx. 3-4 minutes, wait for pressure to reach a value below 5*10-7
10. If turbo and pump are separately operated- Cart 2
    1. Since turbo is off, go ahead and throttle open the roughing pump
    2. Ensure the CCG is working, CANNOT continue without it.
    3. 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 5*10-7 or close to it.
    4. 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.
       1. This would be an indication that the RGA was last vented or has off-gassed (oops!).

Software Guide:

*Important: RGA Sum of Calibration.ppt

1. Log in to computer, go into 'Process Eye Professional' 
2. Click on 'Recipe List', then click on 'Easy View'
3. The RGA connected to computer through ethernet will have a distinct filled in symbol to its left. 
   1. This will open up an EasyView tab of respective RGA device
   2. If the device does not automatically connect, refer to this how-to document: https://confluence.slac.stanford.edu/x/dRoEEw
4. Turn on the filament, and select analog data view (see section 10 of HPS document for more details on Process Eye Professional).
5. Collect data for 5 minutes at accuracy 5 before continuing. At Accuracy of 3 is fine.
6. Note the pressure at the cold cathode. Slowly open the leak valve until the pressure slowly starts to rise. Keep opening the leak valve until the pressure at the cold cathode reads 1e-6 torr.
   1. At this point the 28 AMU (nitrogen) should be the highest peak in the RGA scan.
7. Open a bar graph and use the marker tool to select all the highest peaks on the graph. At accuracy of 6.
   1. Input the values to the provided spreadsheet to get the pressure that the RGA thinks it sees and to then get the percentage of the total pressure the nitrogen provides
   2. Spreadsheet: https://docs.google.com/spreadsheets/d/15D6ebvvUcVcYYJx70cF8eDa5uTvCGoae9l0nPlBS-ts/edit?usp=sharing 
      1. Example on Cart 2 Tab, at the top (reference Figure 3). Copy & paste calibration example to desired spot
8. BEGIN CALIBRATION
   1. If you have issues connecting to RGA, or get following error, ensure RGA labeled IP matches the IP that ProcessEye assumed IP.
      1. If not, you will need to go into RGA Device Manager, and reconfigure the RGA
         1. 'Configure' Tab>Click on desired RGA>Insert (IP:Label IP)(Subnet: 255.255.0) (Gateway: Leave Empty)

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