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--- gas_handling_system [2013/12/13 20:58]
pereira created
+++ gas_handling_system [2013/12/13 21:37]
pereira [Removing Gas from Focal Plane Detectors]
@@ Line 15: / Line 15: @@
   * A log file should be specified before operating the gas handling system
       * A window automatically pops up asking for the name of the log file when the program starts
-      * Use the number of the current experiment (or “test”) as the name of the log file and save in file
+      * Use the number of the current experiment (or “test”) as the name of the log file and save in file /intranet/files/departments/operations/s800/TO_BE_SPECIFIED
-//intranet/files/departments/operations/s800/TO_BE_SPECIFIED
       * The On indicator next to Is VI running? will flash until a log file is specified and the program initiates communications with the hardware
@@ Line 29: / Line 28: @@
-Preparation of Gas bottles
+===== Preparation of Gas bottles =====
-	In Data-U6
+==== In Data-U6 ====
-	Ensure I265GV is closed to isolate focal plane vacuum chamber from the rest of the beamline
+      * Ensure I265GV is closed to isolate focal plane vacuum chamber from the rest of the beamline
-	Confirm that the focal plane chamber is under vacuum
+      * Confirm that the focal plane chamber is under vacuum
-	Confirm that the only open gas handling system valves are 4, 5, 6, 20, 21, and 22
+      * Confirm that the only open gas handling system valves are **4, 5, 6, 20, 21, and 22**
-	In the S3 vault
-	Ensure that the gas handling system roughing pump is running and has a good vacuum
-	The pump sits on the floor under the focal plane behind the south support post (PICTURE GOES HERE)
-	The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post (PICTURE GOES HERE)
-	Ensure that the main valves on the gas bottles are open
-	Ensure that the gas bottles are not empty
-	The gas regulators are not normally adjusted.  They should all be set to provide a pressure around 20 psi.
-	The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber.  It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-	The bottle supplying CF4 (tetrafluoromethane) gas for the CRDCs is secured to the cross-brace of the south support for the focal plane chamber.  It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-	The bottle supplying isobutane (C4H10) for the CRDCs is secured to the south support post for the focal plane chamber.  It sits on a scale for monitoring the isobutane consumption – the electronic display for the scale sits on the chiller unit under the focal plane chamber.  It has a mechanical pressure gauge downstream of the regulator. (PICTURE GOES HERE)
-Filling Ion Chamber with Gas
+==== In the S3 vault ====
+      * Ensure that the gas handling system roughing pump is running and has a good vacuum
+           * The pump sits on the floor under the focal plane behind the south support post
+           * The display unit for the pressure at the pump has a needle indicator and is mounted under the focal plane on the south support post
+      * Ensure that the main valves on the gas bottles are open
+      * Ensure that the gas bottles are not empty
+           * The gas regulators are not normally adjusted. They should all be set to provide a pressure around 20 psi.
+           * The bottle supplying the P-10 gas for the ion chamber is secured to the cross-brace of the south support for the focal plane chamber.  It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator.
+           * The bottle supplying CF<sub>4</sub> (tetrafluoromethane) gas for the CRDCs is secured to the cross-brace of the south support for the focal plane chamber. It has an electronic Ashcroft pressure gauge upstream of the regulator (toggle on and off with the “on/off” switch) and a mechanical pressure gauge downstream of the regulator.
+           * The bottle supplying isobutane (C<sub>4</sub>H<sub>10</sub>) for the CRDCs is secured to the south support post for the focal plane chamber. It sits on a scale for monitoring the isobutane consumption – the electronic display for the scale sits on the chiller unit under the focal plane chamber. It has a mechanical pressure gauge downstream of the regulator.
-	Follow instructions under PREPARATION FOR FILLING DETECTORS WITH GAS above
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
-	Confirm that the detector pressure as indicated by the display labeled P.T. #1 reads below a couple of Torr
-	To zero this display:
-	Click on the Slot 3 (PT1) tab to access the details page for PT #1
-	Click the Zero Sensor button
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system
-	Close valve 6
-	Open valve 2; the flow reading at MFC #1 should jump momentarily
-	Fill Ion chamber
-	Enter the desired fill pressure and start the automatic filling process
-	Click on the tab labeled Slot 8 (M-card) IC to access the page with the pressure set point control
-	Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point
-	Click button labeled Return to AUTO Mode on left to start filling/regulation
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling
-	The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior)
-	If necessary, the filling process can be stopped at any time by pressing the valve button labeled Close MFC #1
-	Open valve 9
-	The filling process will take several minutes
-	When the detector is filled, close valve 5
+===== Filling Ion Chamber with Gas =====
-Filling CRDC1 and CRDC2 with Gas
+  * Follow instructions under [[#Preparation of Gas bottles|Preparation of Gas bottles]]
-	Follow instructions under PREPARATIONS FOR FILLING DETECTORS WITH GAS above
+  * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
-	Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr
-	To zero this display:
-	Click on the Slot 4 (PT2) tab to access the details page for PT #2
-	Click the Zero Sensor button
-	Click the Valves tab at the top of the LabView window to return to the overview display of the gas handling system
-	Close valve 22
-	Open valves 10 and 15
-	Open valve 12; the flow reading at MFC #2 should jump momentarily
-	Open valve 17; the flow reading at MFC #3 should jump momentarily
-	Fill CRDCs
-	Enter the desired fill pressure and start the automatic filling process
-	Click on the tab labeled Virtual Ch. 0 (CRDC) to access the page with the pressure set point control
-	Enter the desired pressure (typically 40 Torr) in the field under the knob labeled Set Point
-	Click button labeled Return to AUTO Mode on left to start filling/regulation
-	Click the “Valves” tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling
-	The flow readings for MFC #2 and MFC #3 will increase
-	The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant)
-	If necessary, the filling process can be stopped at any time by pressing the valve button labeled Close MFCs #2 & #3
-	Open valve 25
-	The filling process will take several minutes
-	When the detector is filled, close valve 21
+  * Confirm that the detector pressure as indicated by the display labeled P.T. #1 reads below a couple of Torr
+      * To zero this display:
+          * Click on the **Slot 3 (PT1)** tab to access the details page for PT #1
+          * Click the **Zero Sensor** button
+          * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system
-Removing Gas from Focal Plane Detectors
+  * Close **valve 6**
-	Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while gas is being removed from detectors; the pressure normally stays below 5E-5 Torr
+  * Open **valve 2**; the flow reading at MFC #1 should jump momentarily
-	Ensure that the system is in the normal state for flowing gas through the detectors
-	Confirm that the focal plane chamber is under vacuum
+  * Fill Ion chamber
-	Confirm that the only open gas handling system valves are 2, 4, and 9 for the Ion Chamber and 10, 12, 15, 17, 20, and 25 for the CRDCs
+      * Enter the desired fill pressure and start the automatic filling process
-	Confirm that the detector pressures as indicated by the displays labeled P.T. #1 for the Ion Chamber and P.T. #2 for the CRDCs show the correct fill values (typically 300 Torr and 40 Torr, respectively)
+          * Click on the tab labeled **Slot 8 (M-card) IC** to access the page with the pressure set point control
-	Ensure that I265GV is closed to isolate focal plane vacuum chamber from spectrograph
+          * Enter the desired pressure (typically 300 Torr) in the field under the knob labeled Set Point
-	Stop the gas flow into both detectors by clicking valve buttons labeled Close MFC #1 and Close MFCs #2 & #3
+          * Click button labeled **Return to AUTO Mode** on left to start filling/regulation
-	Isolate the gas supply by closing valves 2, 12, 17, 10, and 15
+          * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #1 will increase and eventually disappear as the readout value overflows the display field (this is normal behavior)
-	Open valves 5 and 21
+      * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFC #1**
-	IMPORTANT:  CLOSE VALVE 25 to protect CRDCs from Ion Chamber pressure
+      * Open **valve 9**
-	Empty Ion Chamber to a pressure at or below the pressure of the CRDCs
+      * The filling process will take several minutes
-	Open valve 8
-	Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes
+  * When the detector is filled, close **valve 5**
-	Finish emptying both detectors
-	Open valve 25
-	Open valve 24
-	Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour
+===== Filling CRDC1 and CRDC2 with Gas =====
-	Close valves 9 and 25
-	Close valves 8 and 24
+  * Follow instructions under [[#Preparation of Gas bottles|Preparation of Gas bottles]]
-	Open valves 6 and 22
-	Enter vault and close main valves on gas bottles:  P-10 for Ion Chamber isobutane (C4H10) and CF4 (tetrafluoromethane) for CRDCs
+  * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while detectors are being filled with gas; the pressure normally stays below 5E-5 Torr.
+  * Confirm that the detector pressure as indicated by the display labeled P.T. #2 reads below a couple of Torr
+      * To zero this display:
+          * Click on the **Slot 4 (PT2)** tab to access the details page for PT #2
+          * Click the **Zero Sensor** button
+          * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system
+  * Close **valve 22**
+  * Open **valves 10 and 15**
+  * Open **valve 12**; the flow reading at MFC #2 should jump momentarily
+  * Open **valve 17**; the flow reading at MFC #3 should jump momentarily
+  * Fill CRDCs
+      * Enter the desired fill pressure and start the automatic filling process
+          * Click the **Zero Sensor** button
+          * Click on the tab labeled **Virtual Ch. 0 (CRDC)** to access the page with the pressure set point control
+          * Enter the desired pressure (typically 40 Torr) in the field under the knob labeled **Set Point**
+          * Click button labeled **Return to AUTO Mode** on left to start filling/regulation
+          * Click the **Valves** tab at the top of the LabView window to return to the overview display of the gas handling system to monitor filling. The flow readings for MFC #2 and MFC #3 will increase. The LabView application controls the gas mixing ratio based on the flow ratio (scaled with a calibration constant)
+      * If necessary, the filling process can be stopped at any time by pressing the valve button labeled **Close MFCs #2 & #3**
+      * Open **valve 25**
+      * The filling process will take several minutes
+  * When the detector is filled, close **valve 21**
+===== Removing Gas from Focal Plane Detectors =====
+  * Monitor the pressure of the focal plane vacuum chamber (as read out via the I264IG ion gauge) while gas is being removed from detectors; the pressure normally stays below 5E-5 Torr
+  * Ensure that the system is in the normal state for flowing gas through the detectors
+      * Confirm that the focal plane chamber is under vacuum
+      * Confirm that **the only open** gas handling system valves are **2, 4, and 9 for the Ion Chamber** and **10, 12, 15, 17, 20, and 25 for the CRDCs**
+      * Confirm that the detector pressures as indicated by the displays labeled P.T. #1 for the Ion Chamber and P.T. #2 for the CRDCs show the correct fill values (typically 300 Torr and 40 Torr, respectively)
+  * Ensure that I265GV is closed to isolate focal plane vacuum chamber from spectrograph
+  * Stop the gas flow into both detectors by clicking valve buttons labeled **Close MFC #1** and **Close MFCs #2 & #3**
+  * Isolate the gas supply by closing **valves 2, 12, 17, 10, and 15**
+  * Open **valves 5 and 21**
+  * **IMPORTANT:** CLOSE **VALVE 25** to protect CRDCs from Ion Chamber pressure
+  * Empty Ion Chamber to a pressure at or below the pressure of the CRDCs
+      * Open **valve 8**
+      * Wait for the Ion Chamber pressure to reach or drop below the pressure in the CRDCs; this process will take several minutes
+  * Finish emptying both detectors
+      * Open **valve 25**
+      * Open **valve 24**
+      * Wait for the pressure in both detectors as indicated by the displays labeled P.T. #1 and P.T. #2 to reach 0.5 Torr or less; this process will take at least an hour
+  * Close **valves 9 and 25**
+  * Close **valves 8 and 24**
+  * Open **valves 6 and 22**
+  * Enter vault and close main valves on gas bottles:  P-10 for Ion Chamber isobutane (C<sub>4</sub>H<sub>10</sub>) and CF<sub>4</sub> (tetrafluoromethane) for CRDCs

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