logging in or signing up operation of a typical diffusion pumped ... msmurali Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 390 Category: Education License: All Rights Reserved Like it (0) Dislike it (1) Added: January 21, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: bprasad2005 (30 month(s) ago) This quite useful for an educator Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Operation Guide : Preliminary Rotary pump Diffusion pump Rough pumping the vacuum chamber Pumping to high vacuum To remove/replace items in the chamber Shutting down the system System operation Operation Guide Preliminary : Preliminary This assumes that everything is off initially and that the chamber (bell jar) is in atmospheric pressure to start with Switch on the power Turn on water supply All the valves are closed Rotary Pump : Rotary Pump Switch on the power to rotary pump Pump will be noisy and spew oil vapor out its exhaust, when starting from atmospheric pressure The noise should subside as the vacuum improves Diffusion Pump : Diffusion Pump Open the fore-line valve to the d.P. And wait while the pirani gauge 1 is below 200 milli torr Switch on the diffusion pump heater and wait for half an hour Link Never let a hot D.P. see high or atmospheric pressure Rough Pumping the Chamber : Rough Pumping the Chamber Make sure that the air vent valve to the chamber is closed Close the fore-line valve to the diffusion pump Now open the roughing line valve Link Pressure on the pirani gauge 2 should begin to drop If O.K. Proceed to pumping the chamber to high vacuum else test for leakage Pumping to High Vacuum : Pumping to High Vacuum Close the roughing line valve Open the fore-line valve Then open the high vacuum valve Wait for few minutes then start the ion gauge (penning gauge) Wait till the gauge pressure is above 1?10-5 torr Link A good practice is to switch the gauge off and make only spot checks To Remove/replace Items in the Bell Jar : To Remove/replace Items in the Bell Jar Switch off the ion gauge Close the high vacuum valve Open chamber vent valve Wait for the chamber to rise to atmospheric pressure Raise the bell jar Remove/replace items Check bell jar sealing surface and base plate for dirt and wipe if necessary Cover the bell jar Shutting Down the System : Shutting Down the System Emergency shutdown Close all valves on the system Shut off the diffusion pump Complete shut down Remove items from the chamber and re-evacuate the chamber Switch off the gauges Leave the bell jar under vacuum Switch off power to diffusion pump Run the rotary pump with fore-line valve open (cooling) Close the fore-line valve leaving d.P. Under vacuum Switch off the rotary pump Slide 9: If you can’t get the chamber down to 200 milli torr or less in about 15-20 minutes, there is most likely a leak Close the roughing valve and reopen the fore-line valve and arrange to test the leakage Return You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
operation of a typical diffusion pumped ... msmurali Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 390 Category: Education License: All Rights Reserved Like it (0) Dislike it (1) Added: January 21, 2009 This Presentation is Public Favorites: 0 Presentation Description No description available. Comments Posting comment... By: bprasad2005 (30 month(s) ago) This quite useful for an educator Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript Operation Guide : Preliminary Rotary pump Diffusion pump Rough pumping the vacuum chamber Pumping to high vacuum To remove/replace items in the chamber Shutting down the system System operation Operation Guide Preliminary : Preliminary This assumes that everything is off initially and that the chamber (bell jar) is in atmospheric pressure to start with Switch on the power Turn on water supply All the valves are closed Rotary Pump : Rotary Pump Switch on the power to rotary pump Pump will be noisy and spew oil vapor out its exhaust, when starting from atmospheric pressure The noise should subside as the vacuum improves Diffusion Pump : Diffusion Pump Open the fore-line valve to the d.P. And wait while the pirani gauge 1 is below 200 milli torr Switch on the diffusion pump heater and wait for half an hour Link Never let a hot D.P. see high or atmospheric pressure Rough Pumping the Chamber : Rough Pumping the Chamber Make sure that the air vent valve to the chamber is closed Close the fore-line valve to the diffusion pump Now open the roughing line valve Link Pressure on the pirani gauge 2 should begin to drop If O.K. Proceed to pumping the chamber to high vacuum else test for leakage Pumping to High Vacuum : Pumping to High Vacuum Close the roughing line valve Open the fore-line valve Then open the high vacuum valve Wait for few minutes then start the ion gauge (penning gauge) Wait till the gauge pressure is above 1?10-5 torr Link A good practice is to switch the gauge off and make only spot checks To Remove/replace Items in the Bell Jar : To Remove/replace Items in the Bell Jar Switch off the ion gauge Close the high vacuum valve Open chamber vent valve Wait for the chamber to rise to atmospheric pressure Raise the bell jar Remove/replace items Check bell jar sealing surface and base plate for dirt and wipe if necessary Cover the bell jar Shutting Down the System : Shutting Down the System Emergency shutdown Close all valves on the system Shut off the diffusion pump Complete shut down Remove items from the chamber and re-evacuate the chamber Switch off the gauges Leave the bell jar under vacuum Switch off power to diffusion pump Run the rotary pump with fore-line valve open (cooling) Close the fore-line valve leaving d.P. Under vacuum Switch off the rotary pump Slide 9: If you can’t get the chamber down to 200 milli torr or less in about 15-20 minutes, there is most likely a leak Close the roughing valve and reopen the fore-line valve and arrange to test the leakage Return