Daya Bay RPC Gas Prototype System User`s Manual
Contents
1. 3 Interface to the slow control system Daya Bay RPC gas system will send signals to the slow control system for on line monitor and emergency control The following is a list of items that have been considered in gas system design e Gas flow rate for all four components the total flow rate and dry wet branches flow rate for the gas mixture Gas mixture humidity Gas bubbling rate for every sub branches to locate the leaking RPC module Gas pressure before the mass flow controller Cylinder weight for Isobutane R134A and SF6 Ventilation air flow rate monitoring HAD sensors monitoring Stand alone weather station device in the gas room will monitor the room temperature air pressure 30 All of these signals are summarized in the table 2 In the present prototype system the status crate has not been provided therefore the slow control signals listed in Gas status crate section are not available for now Flowmeter crate Flow rate Isobutane DC level 0 10V J3 Flowr rate Argon DC level 0 10V J3 Flow rate R134A DC level 0 10V J3 Flow rate SF6 DC level 0 10V J3 Total flow rate DC level 0 10V J3 Branch 1 flow rate DC level 0 10V J3 Branch 2 flow rate DC level 0 10V J3 Pressure crate Pressure Isobutane DC level 0 10V J6 Pressure Argon DC level 0 10V J6 Pressure R134A DC level 0 10V J6 Pressure SF6 DC level 0 10V J6 Gas status crate HAD sensor stat2. 0 50 sccm N Flow In the production version to reduce the cost of gas system the redundant mass flowmeters have been eliminated Ch 3 Isobutane C4Hj0 0 200 sccm N2 Flow Ch 4 Argon Ar 0 1000 sccm Nz Flow The gas flow controllers have been calibrated by soap bubbler The calibrated Scaling Control Fact SCF for four channels is summarized in Table 1 Table 1 Gas flow controller s parameters Channel Gas Full Gauge Gas Calculated Calibrated Calibrated range for factor Correction Scaling at flow rate N2 sccm Factor Control sccm Factor SCE i pa ow w os 312 36200 E a 3 Gite 200 0 omn ae A n o s a os s Obtained from http www teledyne hi com Manual Flow 1 1 1 052007 20Nall 20Mass 20Flowmeter pdf The Scaling Control Factor SCF are shown on the 247D rear panel potentiometers The SCF is the product of the Gauge Factor for the MFC in use and the Gas Correction Factor for the gas in use SCALING CONTROL FACTOR GAUGE FACTOR x GAS CORRECTION FACTOR In this table the calculated SCFs and the calibrated SCFs have some discrepancy Power ON OFF Switch Flow Indicator Flow Control Digital Panel Meter LED Switch p ak awl ae Flew stm Few Sart now re i IT OPT Bio d 1 Q Read Reed i cura gt Set Point Source Switch Channel Selector Read Set Point Switch Set Point Control one are Flow Set PE Flow ae ear Flow gL OU gl 1792 174 icy Read Ext R
3. Fig 15 B Gas distribution bottom and digital bubbler top panels t FLOW D STR BUTO 17 2 3 1 Flow resistor and inlet overpressure protection bubbler We have calculated the pressure drop AP for the RPC gas flow path The RPC itself won t bring in noticeable pressure drop due to large cross section The major pressure drop is coming from the long tubing A CERN web site provides a calculator to calculate such pressure drop http detector gas systems web cern ch detector gas systems Tools deltaP htm Figure 16 shows the verification of this calculator with some real test done by Bob Messner of BaBar Pressure Drop For Tubing 0 5 114 polvyilo is 174 OD tubing e Delta F per 100 of Teflon o O F ere EE ARE E Delta P per 100 of Polyflow of CERN calculator per 100 finches H20 Tec ana EN EEE Seuss ee Se T mH 1 4 teflon has a larger ID thant 4 polyo 9 44 Inch H20 Z 0 7 PE ET Enina Pani ubh nnana E iran ndidinei Sai tikilnd iebiadWvoaidsiyis ihitai p 3 i P DA Dean ee aogas eet o ac 0 15 inch H20 z 0 0 0 10 ZU 30 40 50 BU 0 046 inches H20 Flow fcofmini for true 1 4 inch ID tubing Fig 16 Verification of CERN pressure drop calculator Use this tool to calculated the gas mixture 75 21 4 Ar R134A Isobutane which is very close to OPERA gas mixture under maximum 5 volume changes day flow rate The calculated pressure drop
4. _ a a Oo On Aa oO control crates Fig 1 Gas prototype system building blocks 2 1 Gas cylinders The prototype gas system skips the cylinder switchover panels Four gases are simply connected to the inlets on the gas mixing panel via 6mm Swagelok fittings After properly connected the tubing careful leakage checking must be performed Many different types of the leak detector can be used such as Matheson Model 8066 LeakHunter Plus The leak rate at all new connected fittings must be at the undetectable level with the maximum sensitivity setting of the leak detector For the Matheson Model 8066 LeakHunter Plus the maximum sensitivity for Ar is 1x10 ml sec for R134A is 1x10 m sec There is no setting for CaHio and SF we can use the setting of Ar and R134A respectively for their leak detection 2 2 Gas mixing and control system This system consists of gas mixing panel and three crates flowmeter crate pressure crate and power supply crate The gas mixing panel is shown in figure 2 and the block diagram of the monitor control system is shown in figure 3 In the prototype system the safety monitoring crate is not included so in figure 3 the system status crate block should be ignored Mix GAS OUTLET Mix GAS OUTLET SAMPLE ro HO OUTLET TO PORT BUBSLER TO RPCS VENT OUTLET rf of oT C2HAF4 SF i WIF MIF JPW MIF hel Me H H ESV q I ESV MFM MFM STATIC MIXING 1 TUBE MFC MFC LEGEND C
5. on the desktop it will pop up the following window File Edit View Project Tools Window Help Dae al bbele Jy yn ED p AD A AD Workspace x Pon O O Ij Click File on the top menu bar then OpenlWorkspace the bubbler software workspace is in the following directory C Daya Bay Gas Bubbler bubbler bubbler16ch 09092008 bubbler16ch v2 eww Tinting If Filo 2 TE Daye Bey gaa ayatem digital bubbler ropdeut Sasad on ENPI Rockol fab programe bosni R Ejbubblertfchv Debug v Eha origin Rocket Lah cada wea written by Vasarlaos Papathanakes BB bubble Gch v2 c Departaent of Fhysrea Princeton University THES pew progres is crested on Feb 5 2008 C Le Tae aapa of channela wate af aingie chanse pethad be pin the ADC ara T00 C LE So far merim f channels can be readout by this pods couldn t suke 1 channels werk in this soquesce of channels mode Therefore readout 14 chenmrls hes to be comploted in 2 steps J chanmelasstep This code bss bean tested with real bubblars ihr di C Lu Total data points are 280 ondy record the tiss mrk at bogimging of each record line Writ l00 used bet tw data points araldi Lu Department of Physics Princeton University ay inclade intrinsics be Hinelude cmspadine Lie be inA20F161 x nausea ietine __ Wdecine Www zk 8 STAR type dafinitions for coutiaiaoce with aicrocoatrollara 7 i i E At ld bite 7 P Ji bite y defied FLASH DATA Ce 2000 sy Mata copy ii Flash altar
6. Because we select the data records after the Data_ID 2560 thus the fetched data starts from Data_ID 2561 P iySGL Query Dneeser Conmection neot localhost JI06 newtest Fie Grit View Query Soret fosk Wines MS Enterpime Help Select FROW newtest newtrequencydate WHERE Date IO 2560 SELECT PROM heefrequenepaat a ea back meh SELECT FROH test frequencydate where date_subi curdatel interval 1 dayi Date_ Time tee frequencydats fi G Herua 1 Sebemals Daat Be Dha ia Fda a F hl Condi 1 JTE A T497 ei momay schema he Codi 2 ATENA TENNI Soho Con 3 AU A 1 ROSH cob Cowra AE ba A UE EE T 5 ARIE TETI 6 AeIE A 1 467 To SUIT TEH 8 METE A LRE PUES Orth Lara D aii ae hic 1 Sots 4 1 33h 2 Sa 1 aaa Te eb A E T POE 16 5 13i 5 St AA Denise S SO Oth AA 1 sara AOS Orth A 2 ATRA AWG TO Ob A co Fea a amp Hihii To SO A 70 10 16 TO 1 1 D TPs Syntaa rhen ES Deka Detintion Statements D ia Hi aa 3 PODIE OS E oG Uy tanen TO I D AL Trencectonal and Lodig _ PARR D iibi bimi aiai E MERIME D hiki Sateen D Fi fta fo Premared Statements B RELS OL Fig 28 Illustration of the MySQL Quesy Browser results The datavase avie cousisis UL uve cvurwuuns vara w we uara w uuwe Board the readout board number labeled by their COM port name such as COM21 COM22 Channel sub branch s number for each board from 1 to 16 Date_Time the recording time F_data the measured bub
7. Close close the Bubbler program the Bubbler Program window will disappear immediately Check communication test the RS232 connection between microcontroller and the host PC in this version the COM ports we used are starting from COM21 up in case of bad communication you may want to check the host PC Ports setting which can be accessed through Start Control Panel System Hardware Device Manager Ports COM amp LPT Click on sign on the left of Ports it will expand the Ports to show all Com Ports where you can check if COM Port names are from COM21 up in sequential order Option select the number of boards to be used in the run In the following we ll go through the process step by step 1 Click Open then select file bubbler16ch v3 txt and open it the content of this txt file will show up on the Input window 2 Click Download TI txt File button this will download the txt file to the microcontroller s flash memory 3 Click Run button it will run this just downloaded program for the readout boards you have selected the LEDs in front of these boards will flash for a few seconds 4 Wait for a few seconds to let the microcontroller finish the data taking then click Upload Data button The data in RAM memory of the microcontroller will be transferred to host 25 PC meanwhile the progress bar above the Retrieve Data window will show the transferring status Upon finishing the data transfer a 12 histograms
8. Form1 cs Open Project Web Site E a ia odia Create Project Web Site tiie H EE Form2 cs H EE Form3 cs Getting Started H Form4 cs 2 GraphFrequencyOfBubbles cs What s new in C 2005 G4 InsertData cs Create Your First Application R Options cs Use a Starter Kit c E E How DoI Pr a Learn Visual C A ga Connect With the Community if Rocket ico Download Additional Content Rocket_1_TemporaryKey pFx Bubbler M Bubbler unavailable To change the news channel on the Tools menu click Options then expand E Bubbler Environment and click Startup 0 Errors gs i 0 Messages Description Column Project G Error List E Find Results 1 g Find Symbol Results Immediate Window 7 Command Window Ready Fig 30 Visual Studio window On the left side Recent Projects pane there are several existing projects name move mouse over any one of the project on the bottom of the Visual Studio window it will shows the solution file s name with its directory tree choose the one as below C Daya Bay Gas Bubbler Lu stuff Bubbler test Bubbler CSharp Bubbler sln and click it will open the entire solution project as shown in figure 31 29 23 Bubbler Microsoft Visual Studio File Edit view Project Build Debug Data Format Tools Window Community Help uy del z EL e Debug a 2d 7 A et 3 mji gt Any CPU gt System Drawing icon i a Formi cs Desi
9. Draft V 1 2 Daya Bay RPC Gas Prototype System User s Manual C Lu K McDonald W Sands S Chidzik M Peloso Princeton University 12 2 2008 Table of Contents Introduction Daya Bay RPC gas prototype system 2 1 Gas cylinders 2 2 Gas mixing and fire detector safety monitoring system 2 2 1 Gas mixing panel 2 2 2 Gas flowmeter crate 2 2 3 Gas pressure crate 2 2 4 Gas system power supply crate 2 3 Gas distribution system 2 3 1 Flow resistor and inlet overpressure protection bubbler 2 3 2 Digital bubbler 2 3 3 Digital bubbler program 2 3 4 Access the data with database program MySQL v5 0 Interface to the slow control system Troubleshooting 5 Appendixes 1 SystemLogic_E pdf SystemLogic_E dwg 2 Flowmeter_E pdf Flowmeter_E dwg 3 Pressure_E pdf Pressure_E dwg 4 Powersupply_E pdf Powersupply_E dwg 5 UL compliance Marking of Gas_PanelsV2 xIs 6 msp430f1611 pdf NO m e U References 1 Introduction The baseline RPC gas mixture is Ar R134A Isobutane SF6 65 5 30 4 0 5 1 which has been approved by Daya Bay safety officer as a non flammable gas The RPC gas system will be similar to that used in the BELLE 2 and BABAR 3 experiments in which a gas mixing system distributes the gas mixture to the individual RPCs through simple flow resistors with the output flow from each flow branch being separately monitored by a low cost digital bubbler 4 Mixing of the chamber gases 1s performed with mass
10. Files with _p attached are ascii data files which can be directly read by Excel From any networked computer you can access this database if MySQL v5 0 and MySQL GUI Tools software have been installed These softwares can be downloaded from web for free To run the database query click on MySQL Query Browser icon 26 displayed on the left pane after click Windows Taskbar Start button It will bring up a MySQL Query Browser window as shown in figure 26 MySQL Query Browser 1 2 12 as Mysa Query Browser Connect to MySQL Server Instance Seed orc Server Host Port 3306 Fig 26 MySQL Query Browser window In this window the name of Server Host should be replaced by the host PC s IP address such as 128 112 84 90 which is the IP address of the host PC on Princeton network The password can be obtained from me just send me a request email changguo princeton edu Click OK a Query Browser window will pop up as shown in figure 27 Fig 27 MySQL Query Browser intial window 27 Click File on the top menu bar then highlight Open Query click it it will open a window showing the files in Local Disk C select MySQL data qbquery and Open it This file will appear in the top window of the Query Browser window as shown in figure 28 If we choose the first line to execute place the mouse point at the end of this line then click the right side Execute button it will fetch the database records into the browser s window
11. through 30m long 4mm ID 1 4 OD Polyflo tubing 30m long tubing is about the round trip of the gas flow path AP 0 75cm WC The digital bubbler s oil height is set at O0 5cm Total pressure drop through the system is 1 25cm WC After the flow resistor an inlet bubbler is implemented before connecting to RPC it is used as the input overpressure protection for the RPC We set the overpressure protection bubbler at 2cm WC for the prototype system We will make some additional space in the future in case of higher protection pressure threshold needed 7 Bob Messner private communication 18 Under normal operation mode the gas flow rate will be 1 volume change day the pressure drop through 30m tubing will be 0 15cm WC We use Upchurch Scientific U 101 S S tube which is 0 02 bore diameter and 5cm long the pressure drop with such flow rate would be 1 02 cm WC that is 7 times of the pressure drop for 30m long 1 4 Polyflo tubing 2 3 2 Digital bubbler For a gas detector system the bubblers are always used at the outlets of the chambers The digital gas bubbler can provide a quick diagnosis of gas flow on line according to BaBar and Belle it turns out to be a very useful system We use a similar digital bubbler design as Belle RPC used 6 In this system the bubblers are instrumented with the photogates Its working principle is illustrated in figure 17 Without the gas bubble the light reaches the photogate through oil without inte
12. 12 2000 3 S Foulkes et al Gas system upgrade for the BaBar IFR detector at SLAC Nucl Instr Meth A 538 801 2005 4 M Ahart et al Flow Control and Measurement for RPC Gases Belle Note 135 Aug 26 1996 http wwwphy princeton edu marlow rpc gas flow ps 5 A Paoloni et al Gas mixture studies for streamer operation of Resistive Plate Chambers at low rate NIM A583 2007 264 6 Daniel Marlow Glass Resistive Plate Chamber in the Belle Experiment Seminar at Rice University July 9 1999 http wwwphy princeton edu marlow talks rice rice pdf 7 MSP430x 15x MSP430x16x MSP430x161x Mixed Signal Microcontroller Texas Instruments 33
13. A File and Folder Tasks Bubbler_1_1_0_10 File Folder 10 15 2008 9 59 AM za se O dotnetFx File Folder 10 15 2008 8 57 AM mj Rename this file rea hie das CF Bubbler application Application Manifest 10 15 2008 9 59 AM E Move this file C Bubbler _1_1_0_9 application Application Manifest 10 15 2008 8 57 AM A Copy this file P Bubbler _1_1_0_10 application Application Manifest 10 15 2008 9 59 AM Publish this file to the Web A x Application 10 15 2008 9 59 AM 63 E mail this file Xl Delete this file Other Places Bubbler Test G3 My Documents Shared Documents My Computer My Network Places Details Fig 23 Directory of the digital bubbler program 24 You also can simply click Start on Windows Taskbar then highlight Bubbler Program geyser and click it will popup the same window Bubbler Program Dept of Physics Princeton University Chart Help Open Close Check Communication ts and Settings All Program Bubbler es 10152008 l Options To change these go to File Options Retrieve Data Default Download Directory C Documents and Settings V4ll Users Documents Bubbler Data Files Change Directory Upload Data Minutes Stop The Timer 3 Fig 24 Bubbler GUI window Click File on the top menu bar will bring up a drop down menu with four choices Open open the executable data acquisition program and wait for being download to the flash memory of the microcontroller
14. V CHECK WALVE IY THLET IsOLATION VALVE FTR PARTICLE FILTER REG PRESSURE REGULATOR AOR PRESSURE TRANSDUCER ESV EMERGENCY SHUTOFF VALVE MFM MASS FLOW METER MFC MASS FLOW COMMROLLER Oly OUTLET OLATION VALVE GWV GAS VENT VALVE SPV SAMPLE PORT VALVE GMV GAS METERING VALVE Fig 2 A Gas mixing panel See Appendix 1 SystemLogic_E pdf for large scale diagram Photo of gas mixing panel Fig 2 B SYSTEM STATUS CRATE wa La A qi 2 lt lt a AIR VENTILATION e POWER SUPPLY CRATE HV INTERLOCK ALLA DOSE LE DE oe miler mee bt cH He W a lt uo N t aata r HAD SENSORS e wre an oT TO SOLENOID VALVE FROM GAS CONTROL PRESSURE PRESSURE PANEL AIR FLOW PRESSURE OK GAS PRESSURE CRATE temas lt lt renee l oe che anm A soa r WREN be et m e So f aja rreasums P arami tS TO HV FLOW LOW INTERLOCK INTERLOCK CONTROL Fig 3 Block diagram of the gas mixing and detector fire safety monitoring system 2 2 1 Gas mixing panel The gas mixing panel has incorporated the BaBar RPC LST gas system experience and Daya Bay RPC system s requirement This mixing panel can mix 4 gases including small amount of SF6 which is in 0 5 of total flow rate level To mitigate the possible interruption due to malfunction of the gas flow controllers the whole system is constructed on rather spacious panel and uses VCR fitting throughout the entire
15. ase 2 Bypass button has been pushed After 5 it will turns off automatically unintentionally Histograms show COM port lost connection 1 Check COM port communication Start all zero Control PanellSystemlHardwarelDevice Manage click Ports COM amp LPT to see if all required COM ports are there and in right Order Unplug the USB cable then plug in sometime it may solve the problem 2 Sometime the electric interference such as plug in a new device into the same power strip may disturb the COM port communication The above method may also solve the problem No data file saved A possible minor software bug may Restart the Bubbler GUI may solve In the relevant be the cause a single bad data this problem Will fix the software bug subdirectory blocked the following data file operation but the database records are OK 32 5 Appendixes 1 SystemLogic_E pdf SystemLogic_E dwg 2 Flowmeter_E pdtf Flowmeter_E dwg 3 Pressure_E pdf Pressure_E dwg 4 Powersupply_E pdf Powersupply_E dwg 5 UL compliance All parts used in the gas system are checked for their UL compliance detailed information is summarized in Marking of Gas_PanelsV2 xls All parts are UL compliant 6 msp430f1611 pdf MSP430x15x MSP430x16x MSP430x161x Mixed Signal Microcontroller References 1 C Lu and K McDonald DayaBay RPC Gas Safety System Design June 19 2008 DocDB 2691 2 A Abashian et al Nucl Instr Meth A449 1
16. be sampled by the ADC The system will be running for a few seconds that is long enough to collect several cycles of the bubbles All the data is stored in the RAM memory of the microcontroller At the end of the data taking cycle the program will set all 8 bits up to 1 fora specific register U1 TXBUF that is the serial port interface on the microcontroller A host PC is supervising the microcontroller readout board through RS232 port It checks U1TXBUF routinely if all 8 bits are up it will readout the data from RAM and store the data in the PC then starts over the whole process again A USB extender pair is used to connect the USB port on PC to a USB hub with 7 USB slots The CATSE cable used to connect the pair of USB extender can be as long as 100ft Each USB slot through a USB to RS232 convertor cable is connected to a digital bubbler readout board For the far hall we need 11 16 channel bubblers and for the near hall we need 7 16 channel bubblers Therefore at near hall we only need one such hub and at far hall we need two hubs to handle all digital bubblers Pi mr Or eM OT ewe HOWE OS Iwe SES SNRARAMSARA TERS s unwell SI SSRN RRA SBR S OS CSR a T C2 I Fig 18 Digital bubbler photogate PC board schematics The hardware of the16 channel digital bubbler with the oil catcher is shown in figure 19 Fig 19 16 channel digital bubbler with oil catcher 20 The schematics of the microcontroller readout test board and
17. bling rate in Hertz Click File and highlight Export Results click it on the drop down menu you can select various file format For example if you want to export the data to Excel format click the fourth line If you already checked the Query Options Open results in associated application after export Click Tool menu then Options it will direct open an Excel file with the data set you have selected A sample Excel strip plot is shown in figure 29 we can see the bubbling rate measured by the digital bubbler is reasonably stable 2 1 8 1 6 1 4 1 2 1 0 8 0 6 0 4 0 2 1 3 5 Fj 5 11 13 15 17 19 271 23 25 27 Fig 29 Sample strip chart of the bubbling rate of one channel Y is in H2 28 The GUI is written in C with the software development tool Microsoft Visual Studio Click Ed Microsoft visual Stu the icon on the desktop Visual Studio 2005 window will pop up as shown in figure 30 Bubbler Microsoft Visual Studio Fie Edit View Project Build Debug Data Tools Window Community Help Microsoft eq Solution Bubbler 1 project Visual Studio 2005 CP Bubbler E Sa Properties H aj References Recent Projects isual Studio Developer News H Resources E app config The current news channel might not be valid or your Internet connection might be o Board cs ClassDiagram1 cd 3 ClassDiagram3 cd Z Bubbler ClassDiagram4 cd B Bubbler FileSystemHandler cs B Bubbler Lu ja 5 flip txt J
18. e Simpson meters reach normal value no warning sign on any of the meters then release the button By doing this the system will lock itself in a normal operation mode until the next abnormal state occurs After you push this button the green light labeled as Flow Interlock OK should be on Also the water branches green light should be on red light should be off The water branches are used for adding water vapor into the gas mixture There are three Simpson meters to display the flow rate for branch 1 2 and the total Branch 1 gas mixture will be bubbling through water then combine with the dry gas mixture from branch 2 The metering valves on branch 1 and 2 can adjust the flow ratio between them thus adjust the water vapor content in the mixture For the present set of the prototype system the water bubbler is not provided you can connect either branch to the RPC chambers and just simply shut off the other branch Figure 8 shows the picture of the front and rear panels of the flowmeter crate 11 INTERLOCK BYPASSED BYPASS TIMER Fig 8 Front and rear view of the flowmeter crate 2 2 3 Gas pressure crate The gas pressure crate is used for displaying the gas pressure at the upper stream of the flow controller for each gas The gas pressure sensor is MKS Type 892 transducer When any gas shows lower than preset pressure limit this crate will generate warning signal shut off the solenoid valve that will in turn shu
19. e this crate will send signal to power supply crate to shut off the solenoid valve and consequently shut off all four gases This crate also sends the analog signals of gas pressure to slow control system for on line display The front and rear panels for the pressure crate is shown in figure 11 o ME jae Ni Vi To E n RPC GAS PRESSURE Sio a E P GAS PRESSURE py University 8 High Energy Physics Low OK CAS Fig 11 Front and rear view of the gas pressure crate 14 2 2 4 Gas system power supply crate The power supply crate provides the DC power to all flow meters solenoid valves Figure 12 shows its schematics Fae rie iTA oe A Ta RA det PROGR FETE E Lt e Te eee ee ee n rr bce LE gi PLIE WEET aL Di mi l ie mE THE a ESE i mm Le ea ELEH Loree ba om CETLE a ay k Leto i na Aeh Fa RPC GAS PUWER SUPPLY CRATE Fig 12 Gas system power supply crate The logic diagram of this crate is shown in figure 13 See Appendix 4 Power E pdf for details 15 RPC HV interlock from fire safety flow rate gas pressure status solenoid valve power out from MKS gas flow meters Flowmeters analog to flowmeter crate 15V 15V DC powers Fig 13 Logic diagram of the gas system power supply crate Power supply crate provides DC power 15V to all seven MKS flow meters It also provides 24V DC power to the solenoid valve It takes status information from flow crate
20. ead Ext Read Ext Read aan ad Decimal Point Selector Switches Scaling Controls Line Voltage Selector Interface Connector J5 AC Line Cord MFC Connectors H J4 net Interface Connector J6 Channels 1 4 Fig 4 MKS 247D four channel readout box Top front panel Bottom rear panel Detailed information on using this box can be found from MKS Type 247D Four Channel Readout Instruction Manual Here we just give a brief description of this control box MKS 247D is designed as power supply readout and set point source for four analog mass flow controllers The 247D unit consists of a power supply four signal conditioning channels four set point circuits and a digital panel meter DPM to display the flow rate of any single channel of a MFC The rear panel provides four connectors via cables they are connected to four mass flow controllers The following test results are obtained with OPERA gas mixture which is different from Daya Bay RPC baseline gas mixture After it is delivered to IHEP the mixing ratios have been changed to the latter mixture Since isobutane is a flammable gas its ratio in a gas mixture needs to be controlled below its flammable limit Unless you are experts and want to make your adjustment to the mass flow control system you are not supposed to touch ANY of the dials knobs and switches on both front and rear panels Otherwise you might change the mixing ratio and make a flammable gas mixtu
21. flow controllers The electronic bubbler system monitors the chamber gas flow by counting gas bubbles in a small oil bubbler as they pass a photogate Detailed histories of the output gas bubbling rate will be available via a local host PC Slow control system and any other authorized networked PC can obtain all data through MySQL database on this host PC Four gases will be input from four auto manual switchover panels to minimize interruptions of the gas flow during chamber operation An extensive detector safety and fire safety system with status monitors and interlocks will be implemented via four gas control crates This prototype system is a simplified version of the Daya Bay RPC gas system The aim of this prototype system is for using at IHEP and Daya Bay SAB during RPC Q C period The gas cylinder switchover panels and gas cabinet are not implemented the safety system is not included Part of the slow control signals are provided which can be used for slow control group testing their hardware software Through the longer term operation of this prototype system we can gain experience and get feedback from IHEP users to further improve the gas system This manual is only used for the prototype system The final gas system operation manual will be provided when the system is delivered 1 Daya Bay RPC gas prototype system The gas system building blocks are shown in figure 1 In the following sections we ll describe each block in details wn
22. gn Bubbler GraphFrequencyOfBubbles cs Formi cs Formi Designer cs blink2 txt Test938 txt out txt flip txt 7 Bubbler Program Dept of Physics Princeton University File Chart Help Status menustrip1 27 openFileDialog1 timer1 Error List A 0 Warnings i 0 Messages Description Program Bubbler Download TI txt File Retrieve Data Default Download Directory label2 Upload Data Minutes Stop The Timer 3 a Column Project rr Error List 5 Find Results 1 det Find Symbol Results E Immediate Window gt Command Window gt Ol oF 54 3t a Solution Explorer Bubbler a OE ELLA a Bubbler B iy Properties S app manifest AssemblyInfo cs a Resources resx Resources Designer cs 3 Settings settings Settings Designer cs Sj References gt Resources blink2 txt flip txt a out Ext S Test938 txt app config Board cs 2 ClassDiagramt cd a ClassDiagram3 cd 2 ClassDiagram4 cd c FileSystemHandler cs flip txt CE Formi cs Form Designer cs Form resx EE Form2 cs EE Form3 cs ES Form4 cs Form4 Designer cs Form4 resx GraphFrequencyOfBubbles cs InsertData cs EE Options cs c ParseData cs Pra cs Wf Rocket ico Ep Rocket_1_TemporaryKey pfx Rocket_TemporaryKey pfx Pro Sams as Properties 4 Formi System Windows Forms Form ARIELA E Ready Fig 31 Project Bubbler opened in Visual Studio
23. its picture are shown in figure 20 Figure 21 is a photo of this prototype system XIN XOUT Dee DWVes Acc Aes HSTNMI Pr Po Ps Py Ps P re T a ee ee ee er SEE a ees EE T ey aE ae ae a 7 bj bo bo e R a E R a j s Vs I Rosc i 5KB RAM VO Port 2 ata 6 i XTSIN y j Bi with l XT20UT Interrupt j 5KBRAM Capability l MELK EN N l J MAB TIE tT OJU fd MDB 16 Bit oy eu MOB Bit i P ft 7 ra a ZS i l i _ Hardwares i i TCK Multiplier Pia A i bilo Timer _B7 i Timer A3 S ad E oil LWSARTO USART i 300 Ps Brownout ania Fa MACMACE 3 Channels 15 16 Bit i i i TETE F i En PI a a H E 5 E EA nes a bt E ERSAARASAARNSARRN giblat elikis BSL Interface Fig 20 B Digital bubbler readout board schematics 21 4 Host PC and Through flat cables connect to bubbler photogate PC boards Digital bubbler readout crate 7 Port USB hub with 7 USB to RS232 converters USB extender with 100 ft CAT S5E cable Fig 21 Digital bubbler readout crate and its host PC with USB extender 100 ft long CAT SE cable The software development tool for the TI microcontroller readout board is AR Embedded Workbench The version 3 30A is a free distributed version please don t upgrade to newer free 22 distributed version that won t work properly for bubbler readout program Click the icon
24. on Flow rate signal to slow control Flow interlock bypass 5 push to actuate Fig 7 Logic diagram of the flowmeter crate This crate displays the gas flow rate measured by the flow meters controls a relay contact that closes on normal flow rate and opens on bad flow rate Send this signal to gas pressure crate which will control the solenoid valve The abnormal flow rate pressure signal will shut off the solenoid valve which in turn will close all gas inlets to the mixing panel In reality the gas flow rate pressure fluctuation due to power supply glitch and or atmospheric pressure sudden change is quite often during certain season To eliminate this type of interfere there is a BYPASS TIMER push button push this button can bypass the status check logic for 5 minutes meanwhile a buzzer will be actuated to remind you that the bypass is acting keep the solenoid valves open for such time period Usually within this period the environmental fluctuation would calm down and return to normal therefore the gas system will continually operate w o interrupt When you see all flow rates and pressures show normal value the Simpsons show no warning signs on the right side bar you should push the RESET START button and the Flow Interlock OK green light should be back on There is a RESET START button on the front panel When the entire gas system is just powered up push and hold this button down until all seven flow rates displayed on th
25. pressure crate then controls RPC HV interlock and solenoid power output In case of any abnormal state occurring such as low flow rate low pressure warning it will actuate the RPC HV interlock shut off solenoid valve There are four lights on the front panel 15V 15V 24V solenoid Valves open In normal case all of them should be on Figure 14 shows the front and rear panels of the power supply crate Fig 14 Front and rear view of the power supply crate 16 2 3 Gas distribution digital bubbler system The gas mixture after the mixing system needs to be distributed to every RPC in an experimental hall The design goal can be summarized as follows e Uniformly distribute the gas mixture to every RPC in the system e Divide the RPC gas flow in one experimental hall into several panel branches of which each will be further split to 16 sub branches In case of one sub branch has leaky RPC the rest of the system should not be affected e At the end of each sub branch should implement a monitoring device to check if there is any leaky RPC The prototype gas distribution digital bubbler system is one such panel branch A sketch diagram of this system is shown in figure 15 A Prototype gas distribution digital bubbler system To exhaust plpe 16 branches gas mixture from mixing system Over pressure protection bubbler HE ic Fig 15 A Gas prototype distribution digital bubbler system
26. re without your notice Please take it seriously The only thing you are supposed to do if you are on shift is choosing each channel by rotating the channel select knob and read the digital meter Compare these numbers with the preset value and the displayed numbers on Gas Flowmeter crate all three sets of numbers should be very close The reading on gas flowmeter crate has been adjusted at the total flow rate of 100sccm If you are running the system at different flow rate the reading might be somewhat different from flow controllers and could be a few percent of deviation The operation of MKS 247D is set in the ratio mode the channel 1 Isobutane is the master channel the other three channels are slaves On the front panel the Set Point Source Switch is set at Ratio position for channel 2 3 4 and at Flow position for channel 1 If you need to change the total flow rate and maintain the mixing ratio unchanged you only need to change the flow rate of the first channel For Daya Bay gas mixture the channel 1 master channel changes to R134A Isobutane becomes channel 3 The other two channels are the same as before A Varian 3900 GC system has been used to verify the mixing ratio Test results show that from 100sccm to 1000sccm of the total flow rate the mixing ratio holds reasonably well as shown in figure 5 A We also tested the gas mixture in different total flow rate for a 2m x 1m IHEP RPC the plateau curves are very
27. rruption When bubble passes it will reflect partial light and the light intensity at that moment would be reduced thus generates a pulse signal to the photogate PC board fi 5v t To digital bubbler Senne readout board A o B 1a cs A 2000 L a RE a aro i _fa ff soo Lif Pee I a area as ea EEE n H k iA fi iy yt 500 T signal 0 0 2 0 4 0 6 0 8 1 1 2 1 4 1 6 time sec Figure 17 Digital gas bubbler A Mechanical structure of the bubbler B Working principle of the photogate C The digital bubbler output signal recorded by microcontroller it shows 8 channels are bubbling the other 8 channels are not A schematics of the digital bubbler photogate PC board is shown in figure 18 This is a 16 channel board that provides input signal to the microcontroller readout board Each of the microcontroller board can handle 16 channels TI MSP430F1611 7 microcontroller is used on the board figure 20 A shows the functional block diagram of MSP430x161x chip It has 10KB RAM and 48KB flash memory The build in 12 bit ADC can sequentially sample 8 channels of the input 19 at one moment with the sampling rate set by a 32768 Hz 2 watch crystal oscillator When the ADC finishes the sampling for the first 8 channels it will generate a switch signal that subsequently will be sent to two MAX4674 multiplexer chips each of which can handle 4 channels Thus the next 8 channels will
28. similar see figure 5 B That means the gas mixing ratios in the mixtures are similar 100 6 32 6 30 10 Mixing fractioln 0 200 400 600 800 1000 1200 Total flow rate sccm Fig 5 A Gas mixing fraction in different total flow rates OPERA gas mixture eff o 200sccm a eff 500sccm a eff 0 1000sccm Efficiency 5200 5600 6000 6400 6800 HV V Fig 5 B Efficiency plateau of a 2m x 1m RPC chamber in different total flow rate OPERA gas mixture 2 2 2 Gas flowmeter crate The gas flowmeter crate is used to display the gas flow rate from seven mass flow meters four for each gas three for the water vapor control branches total dry branch and water vapor added branch Simpson model H335 controller unit is used for the flow rate display and safety control A normal flow rate band is defined for each of seven flow meters through the Simpson controller if the flow rate is out of this preset band the build in relay of the Simpson controller will be acting accordingly Figure 6 shows the schematics of this crate a ee ee ere uti MT TRR ER L EN d Tree ately CRATE RPC GAS FLOWMETER Fig 6 Gas flow meter crate The logic diagram is shown in figure 7 See Appendix 2 Flowmeter_E pdf for large scale schematics 10 Flow rate display meters Flow interlock signal to pressure crate Flow rate signal from flow meters
29. system that makes replacement easier and faster The redundant mass flow meters are added into the system to cross check the mass flow controllers which is very valuable when the gas mixing ratio is in doubt for detector s unusual behavior Also provided is a sample port that can be connected to a GC system to check the gas mixing ratio in any time An additional port for gas outlet to vent will be used in the case of purging the gas mixing system All four gas inlets are controlled by pneumatic valves indicated as esv in figure 2 which are actuated by pressurized air or nitrogen cylinder at 100psi via a solenoid valve The later is controlled by the power supply crate that will be mentioned later With this arrangement all gas components will be turn on and off at the same time the mixing ratio won t be changing after the system interruption The pressure sensors xdcr in figure 2 will send the output signal to the gas pressure crate where the signals are compared to the preset normal pressure operating range Mass flow meters send the measured signal to the flowmeter crate where the flow rates are checked if they are within the preset normal ranges The mass flow controllers and flow meters are MKS products Four mass flow controllers are controlled by MKS 247D see figure 4 Full flow ranges of the gas flow controllers and flowmeters are as follows Ch 1 Tetrafluoroethane C2H2F 0 1000 sccm N2 Flow Ch 2 Sulfur Hexafluoride SF
30. t off all gas inlet ports on the gas mixing panel Figure 9 shows the schematics of this crate See the manual of the pressure sensor http www mksinst com docs UR 890_892DS pdf gt See Appendix 3 Pressure E pdf for details 12 Usually the flow rate can maintain at the normal level for a while even the gas pressure drops below the normal value The gas pressure drop gives the first sign of the gas cylinder depletion Only the lower limit for the pressure display control Simpsons is set the upper limits are set at much higher value under no circumstance such over pressure warning will occur The gas pressure can be set by adjusting the pressure regulators on the gas mixing panel The recommended pressure is 30 psia for all four gases ii e pe UF nk EEEH Hp et E RPC GAS PRESSURE CRATE Fig 9 Gas pressure crate The logic diagram of this crate is shown in figure 10 Pressure djsplayicontre meters Flowrate status OK Y M flow rate status oo i pressure status to status crate Signal from pressure sensors gt a flow rate and pressure siatus to power crate control solenold valves a i a F s lt Pressure signal to slow control a pressura Hrki i a flowrate 0K Fig 10 Logic diagram of the gas pressure crate 13 The gas pressure display and control is also accomplished by Simpson H335 controllers In case of either flow rate or gas pressure is out of normal rang
31. ta hera define FLASH COUNT OeFOOD s y camber for the riarstron a af Ihe follming Black of cate saka up d a rmsture ff for storing data frem the digital bubbler Sprague bittields reversed Pprages pack 5 struct bubbl ff bubbler data storage allocation 23 The interconnection of the digital bubbler system is shown in figure 22 To digital bubbler photog ate boards Digital bubbler readout crate T Port USB Hub USB extender US 8 extender up to 100 t CATSE cable USEto RSs conwerternicable Fig 22 Interconnection of the digital bubbler system For the production version of this system the host PC will be in electronics room the digital bubbler hardware and readout crate will be located on the RPC supporting platform the distance between two locations will be around 20m Use of the USB extender and one 100 ft CATSE cable should be long enough to link them together 2 3 3 Digital bubbler GUI To open the digital bubbler GUI go to directory C Daya Bay Gas Bubbler Lu Stuff Bubbler test Bubbler Published as shown in figure 23 click setup exe it will bring up the bubbler GUI window as shown in figure 24 amp C Daya Bay Gas Bubbler Lu stuff Bubbler Test Bubbler Published SEE File Edit view Favorites Tools Help ae Back gt i x Search Kea Folders Gii RA Folder Sync Address B C Daya Bay Gas Bubbler Lu stuff Bubbler Test Bubbler Published v Ga Name Type Date Modified
32. us switch O alarm C normal J10 Ventillation status switch O alarm C normal J10 Scale 1 Isobutane switch O alarm C normal J12 Scale 1 Isobutane DC level 0 10V Scale 2 R134A switch O alarm C normal J12 Scale 2 R134A DC level 0 10V Scale 3 SF6 switch O alarm C normal J12 Scale 3 SF6 DC level 0 10V Flow rate status switch O alarm C normal J11 Pressure status switch O alarm C normal J11 HV interlock switch O alarm C normal J11 Weather station Gas Stor Rm temp direct read R5 2932 Gas Stor Rm air presdirect read Gas Mix Rm temp direct read RS 232 Gas Mix Rm air pres direct read Table 2 Slow control signals from RPC gas system 4 Troubleshooting This section is evolving with the running experience your feedback is most welcome All gas flow meters 1 The solenoid valve doesn t open 1 Check if all four gases have show zero flow all pneumatic valves are closed pressures higher than low limits rates 2 Nitrogen gas cylinder does not have 2 Change N2 cylinder enough gas pressure lt 4 atm 3 Any gas channel has lower than 3 Check 247D to see if there is any preset lower flow limit thus shut off switch unintentionally being turned the solenoid valve off Buzzer activated 1 Gas pressure and or flow rate is out Solve the pressure flow rate problem first of preset normal running range then push RESET START button until all flow rates return to normal and rele
33. window will popup Each histogram shows 16 vertical bars each of which represents the bubbling rate for its corresponding sub branch Click on each histogram a larger histogram will popup which is clear enough to read the bubbling rate Click X sign on the upper right corner of the larger histogram will close this histogram window An example is shown in figure 25 F E C Documents and Settings All Users Documents Bubbler Data Files 10282008 1 3_7_56 BAB at EE Board1 Bubbler Program Dept of Physics Princeton University Sele Bubbler Bubbler tes fs Fig 25 Bubbling rate histogram windows In figure 24 there are several other buttons The minutes button is used for setting the time interval between each data taking After click the Upload Data button the program will automatically repeat the data upload data taking cycle according to this minutes setting To stop the timer click Stop The Timer button it will halt the program and change the label to Start The Timer Click the button again will resume the program 2 3 4 Access the data with database program MySQL v5 0 The bubbling frequency data are collected in a database called newtest table name is newfrequencydata The raw data files which can be used to plot the pulse curve for each channel are stored in subdirectory Bubbler Data File under the Shared Documents of the host PC Each day has a subdirectory and each run has next level of subdirectory
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