Magneto-Resistance Calibration Wizard for Cernox Thermometers
Contents
1. Ntemps The number of temperature steps VerFieldS weepRate The verification phase of the calibration process is done as a continuous sweep of the magnetic field at each temperature This parameter tells the PPMS how fast to sweep Too fast of a sweep causes eddy current heating to cause errors Quantum Design PPMS Application Note 1078 202 B O S February 21 2006 Configuration file Description parameters CalibrationMode The wizard can run in two modes a fast mode 0 and a high accuracy mode 1 In the fast mode the field is either always increasing or always decreasing and then it ramps back down to zero If an offset is discovered at that point from the previous zero field apparent temperature a linear baseline is assumed and subtracted In the high accuracy mode the field is varied in a two steps forward one backward set of steps and the baseline is subtracted at each step to account for non linear behavior of the whole baseline EddySettlingTime During charging and discharging of the magnet the effect of Eddy current heating will be noticeable in the user thermometer This is a fixed amount of time the system waits for the heat generated to dissipate NumResMeas At each temperature and field point the wizard takes NumResMeas independent resistance measurements on the User Thermometer Quantum Design does not recommend the use of values less than 5 TimeBetweenMeas This is2. Therm156 cfe Notepad File Edit Format View Help REM Therml56 cfq Thermometer Calibration Original Calibration Table 2ELE 2l 2 2 0 4934 131 1 79994 4092 62 2 0352372 3414 155 2 50296 Thl2dHex 1 21 2 2 3 1 1 20 20 0 3EF6FC313F1FD7113F443200A3F6889032 DBSA7 047 3B8AD8407B7 3AB 3C1 3949 20DA3A1E38E0 34B2 ASDC 3B1F1AAE 38700405 2 New 2D table 7 34411148 3AD6DBD3 3BOEFOR 2B 24C7 9B IBS AADSAZE B2 BAR 3BSE47 A 3B9F3D6E3 CB6BBE 03 ACBRODOSEB6BREFECSE 7 BB 3F95 ES 4BFOAOBSADOADSBSEDD46EB92 8 35A6B Map_ID 21 HOT Therm i Figure 11 Updated TTO Hot thermometer Configuration file with new MR Calibrated 2D table 3 Save the new changes for the thermometer configuration file Note Before using the TTO option reactivate the option anytime you make changes to any of the option configuration files in order for the new changes to be sent to the Model 6000 The new magneto resistance calibrated TTO puck is ready for use after calibrating both thermometers The procedures for installing and using the TTO Option remain the same for the new calibrated puck Quantum Design PPMS Application Note 1078 202 B O 14 February 21 2006 Appendix D Magneto Resistance Calibration for the ACMS Thermometer The ACMS allows you to use the Auto Detection option in the Magneto Resistance Calibration Wizard Hardware installation basically remains the same for the options as if you were setting up to perform AC measurements except
3. Select User Channel 1 for the Hot thermometer or User Channel 2 for the Cold thermometer The wizard will then ask which GetDat channel to calibrate Only one thermometer can be calibrated at a time e If you selected User Channel for the Hot thermometer in Step 3 select Channel 21 e If you selected User Channel 2 for the Cold thermometer in Step 3 select Channel 22 The Magneto Resistance Calibration Wizard will then run the calibration automatically Proceed to the next step once the verification process of the Magneto Resistance Calibration Wizard is complete Quantum Design PPMS Application Note 1078 202 B O 13 February 21 2006 Updating the TTO ThermXXX cfg File With the New MR Calibration 1 Open the new MR calibrated cfg file located under QdPpms Tools Figure 10 MRCalibration_1 cfg Notepad _ OX Thl2dHex 1 21 2 2 3 1 1 20 20 0 3EF6FC313F1FD7113F44300A43F688 DBBA O4 SBR ADS 40 6 3ABSC1 5949 50DASALESSEOQSABRZ ASBDCIBLIFLAAESB SOD fSAA111L4IB SADBDEDS SBOEFOR SB 34C 9R 3B AADI ASB BZBAS SBBE4Z AZ SBYF Sl CBOBEZO0327ACBS 0D0BBOBEFECSB BBSFY5Be4BFOAUB6ADUADSBSEFOD4S6EBY26 3 TBLMODE 21 2 Figure 10 MR calibrated configuration file for the TTO Hot thermometer 2 Copy the 2D table from the configuration file Do not copy the command TBLMODE 21 2 and paste in the TTO ThermxX XX cfg file QdPpms ThermalTransport Calibration under the original thermometer calibration table Figure 11
4. 1 236 22725 476 080606 32 G22 522 45370 29 605596 573 40049 26 642927 629 02570 24 27662 690 22612 21 96342 757 95565 19 658 15 831 95432 17 96986 913 82813 1656 25880 1004 72020 14 70930 1105 78430 13 30872 1218 89560 12 04l42 1345 73240 10 89520 1 480 33920 9 85527 1651 59240 8 91858 1836 92050 8 06920 2049 46790 7 301045 2296 93180 6 60223 2563 156330 5 97202 29018 4921 0 5 40449 s314 37030 4 89013 37865 14840 4 42507 44552 531540 4 00265 5037 72000 3 62154 5875 06600 3 27652 69009 20700 2 9642 O 8199 239070 2 8180 98271 95190 2 42736 11948 156900 2 19278 1 4770 155000 1 978662 18211 76800 1 79863 227902 06700 1 6563502 29 050 75900 1 48629 37957 42100 1 35109 mapdat 25 4 thlmode 25 1 Figure 7 VSM thermometer configuration file to be sent to the Model 6000 Send the new configuration file down to the PPMS Model 6000 using RomCfg32 exe located under OdPpms Tools From the toolbar select Send to PPMS Send Config to send the new configuration file you created above Mageneto Resistance Calibration Wizard For VSM l 2 3 4 5 Run the Magneto Resistance Calibration Wizard The wizard will ask for Auto or Manual Detection Select Manual Detection Then select which bridge channel to calibrate Select User Channel 1 The wizard will then ask which GetDat channel to calibrate Select Channel 25 The Magneto Resistance Calibration Wizard
5. will then run the calibration automatically Proceed to the next step once the verification process of the Magneto Resistance Calibration Wizard is complete Quantum Design PPMS Application Note 1078 202 B 0 Il February 21 2006 Updating the Coil cfg File With the New MR Calibration k De Original Calibration Table New 2D table Open the new MR calibrated cfg file located under QOdPpms Tools Figure 8 Copy the 2D table from the configuration file Do not copy the command TBLMODE25 2 and paste in the VSM Coil XXX cfg file QdPpms VSM Calibration under the original thermometer calibration table Figure 9 As in Figure 9 add MR Therm at the beginning of the 2D table Again ensure that the command TBLMODE 25 2 is not present P MRCalibration_1 cfg Notepad File Edit Format View Help Tol dHex 1 25 223 11 20 20 0 SEEFOO44SF1C5C96S3F413907S3F66L5 SSF R57RF 53 2 46946041 S1 B96 564 6CB9 7 5 9CB2BR4E4 DES S905 FEDESAADIAECSB2DCILUSBRABLAFSBCAAFF 2 a HSAs Foo 44 sA6F4 CORPS 40 PI COESBOSDOFESB464564 s646 78045 B92 EDRs Be4 CB SOR SFOFOFDAL SB5B2 0 42B664 BF RB IB24 3291 BOB FRRAB SOBA SBYCEES SEBRZFODOS BRSUDSESBBSCFE 548B TBLMODE 25 2 Figure 8 New MR Calibrated configuration file with 2D table Coil 064 cfg Notepad File Edt Format view Help lt Coll Configuration File Serial Number 064 Therm TABLE 25 2 2 0 42 60442 439 97808 46 16434 398 56758 50 15573 361 0546
6. 1 25 2 27 3 1 1 20 20 0 3F6A574F3F8466693F9 381278 3FAZF New 2D table AB993927 08B9EO05F9RBA09 ICABAO 6B97B986C65039BC7092 3AAD6B887 3B25 SBASBBU49BA67 S6ALBASAE 36 0BA8 30948849 32 5B5BA9614 3FBASEB4D27 BAF OC 337C5C BDZ D2 SFELO37Ch1E4B 38BCBF41 39426981 3997 98B839C1BO0BF39C9E TBLMODE 25 2 J K me Figure 13 Updated ACMS thermometer Configuration file with new MR Calibrated 2D table 3 Save the new changes for the thermometer configuration file Note Before using the ACMS option reactivate the option anytime you make changes to any of the option configuration files in order for the new changes to be sent to the Model 6000 The new magneto resistance calibrated ACMS coil is ready for use The procedures for installing and using the ACMS remain the same for the new calibrated coil Quantum Design PPMS Application Note 1078 202 B 0 16 February 21 2006 Appendix E Magneto Resistance Calibration for the Rotator Thermometer Similar to the ACMS the Rotator option allows you to use the Auto Detection option in the Magneto Resistance Calibration Wizard Hardware installation remains unchanged for this calibration procedure Refer to the Rotator Option User s Manual for installation procedures and downloading the rotator configuration files The rotator thermometer calibration table is stored on channel 23 and read off of the User Bridge Channel 1 unless using in conjunction with the ACT option When the Rotator option is bein
7. 1 95190 2 427 360 11945 16900 2 19278 14770 15500 1 97502 16211 760600 1 79603 227 MR Therm Tol2dHex 1 25 2 2 3 1 1 20 20 0 3FLOBLDASF343C92 3F5 CP4A3F 7B5202 3F8 b5 SDBYD4ABA SBADOUF2 2 BABS 4Es SBAFOSFISBBLOEZ SCBBLO434FBACFEL SEBYAO0UB4ASADB SBOASBY OCs 3AB964C9 3B543B5A3BAFDB1L45CO0s 86 45C2BBS 3 309 B45F sCB112 6B 3CUUBbCFICIC Z SBUBSY Boo 3ACeLEF BeOAHH UB BFD Ss sDBBOYEZFEBYUSL45 9B99 5 SLI EBADOBACDBASFSEDLOBASLEEB IBAA coil Center 40 10 replace 40 1 with the measured coil center System Calibration 6838 change this number after system calibration Image Mean 800 change the image mean after image effect calibration Image Ratio 1 015 change the image ratio after image effect calibration Image RRR 54 Change the image RRR after image effect calibration Shrinkage Coeff 0 98 calibrated Septd05 on sample chamber SCE43 Delay 000100 change the delay after coil calibration Amplitude Calibration 1 1 5 9996 1 1 1 5 9959 2 9878 2 5 9750 3 9534 3 a Figure 9 Updated VSM coil Configuration file with new MR Calibrated 2D table 4 Save the new changes to the coil configuration file The new magneto resistance calibrated coil set is ready for use The procedures for installing and using the VSM Option remain the same for the new calibrated coil set Quantum Design PPMS Application Note 1078 202 B 0 12 February 21 2006 Appendix C Magneto Resistance Calibration for the TTO Thermome
8. 11C5 3905 BBAES940AF 61 396 3 ACE39AE0AQE349DEDEFE 2A0LE 5BYS9E4 CR93 6BCOBS4SRFEF BY41E6 3BB91D FYBBSCS1BB3Bs 3BBFD4B63568 CBBOFD 3 64C08B8 sOBBbFD39E2B FCBDBFEBSDAAACBSFAY 4ABR942 S0A0BYBAE TBLMODE 23 2 gt Figure 14 MR calibrated configuration file for the Rotator 5 Copy the 2D table from the configuration file and paste in the rotator cfg file QdPpms HR XX X Configuration under the original thermometer calibration table Ensure to also include the command TBLMODE 23 2 when copying the table over to the rotator configuration file Quantum Design PPMS Application Note 1078 202 B 0 I7 February 21 2006 and remove the original command TBLMODE 23 1 Figure 15 This command will activate the 2D table on channel 23 P HR LowRes 277_MRCal cfe Notepad File Edit Format View Help MovecTg 1 0 0537 380 0 Bridge 1 999 02732 100 000 0 0 9 0 _ Mapdat 23 4 Original 2 2 0 39 831879 446 697662 43 173725 400 025391 46 9 Calibration Table 2 243342 5 535042763 2 008721 6 686706e3 1 799124 8 191840e3 1 Thl dHex 1 23 2 2 3 1 1 20 20 0 3EF9FSCL3F21CF B3F46A2 95 SF6B New 2D table AS6405DF 5 36AB11C8 3905 BBAES940AF 61 5965 7 ACES 9AEOADE 39DBDEFB3A01E 5BYS9E4 CB93 6BCOBS4SRFEF BY41Eb 3BB91D FYBBSCS1BB 368 3BBFD4B63568 CBBFD 3 64C08B8 sOBBFD39E2B FCBDBFEBSDAAACBSBFAY 4ABR942 SO0ADBYBAE TBLMODE 23 2 USERTEMP 23 1 6 Lay 2 1 gt Figure 15 Updated Rotator Configuration file with new MR Calibrated 2D tabl
9. 9 268 25333 7l 78219 242 79159 78 90714 219 67096 86 80920 198 76603 95 534186 179 B0692 105 14400 162 86740 1115 73087 147 41000 127 31784 133 47711 140 05607 1120 83331 1154 06 384 109 33437 1659 35099 08 95565 1865 22914 89 49990 204 62778 B0 96083 224 86615 73 2220 24 za 04158 566 23361 271 48741 59 87863 2907 922195 54 2 75971 427 00860 48 93680 359 70259 44 27373 305 13034 40 03310 433 70975 3606 22725 4765 08066 532 77022 522 45370 290 6 5596 573 40049 26 82 921 629 02570 24 276062 000 22812 21 96442 757 95565 19 85815 831 95432 17 96986 913 82813 1686 25880 1004 72020 14 70930 1105 78430 13 30872 1218 89560 12 04142 1345 73240 10 89520 1489 33920 9 85527 1651 59240 8 91858 1836 92050 8 06920 2049 48790 7 30103 2296 93180 6 60223 25 63 16330 5 97292 2918 49210 5 40449 3314 37030 4 89013 37865 14840 4 42507 4352 51540 4 00265 1037 72000 5 62154 5875 06600 3 27652 0909 26700 2 96420 8199 23970 2 68180 9821 95190 2 42 736 11948 16869 900 2 19278 14770 15500 1 97862 18211 76800 1 79863 22792 06700 1 63502 29059 75 GO0 1 48629 37957 42100 1 35109 coil Center 40 10 replace 40 1 with the measured coil center system Calibration 6838 change this number after system calibration Image Mean 800 a the image mean after image effect calibration Z Image Ratio 1 015 ange the Image
10. Ouantum Design PPMS Application Note 1078 202 Magneto Resistance Calibration Wizard for Cernox Thermometers on the User Bridge The Magneto Resistance Calibration Wizard calibrates out the dependence of a thermometer resistance on the magnetic field It holds the PPMS system temperature constant while varying the field to get the calibration corrections Changes in the apparent temperature of the user thermometer are then attributed to magneto resistance effects Use this wizard when you already own a Quantum Design PPMS with a Magneto Resistance calibrated sample chamber thermometer and you want to apply the same calibration to an arbitrary thermometer connected to a PPMS resistance bridge See Appendices for detailed procedures for VSM TTO ACMS and Rotator thermometers A thermometer on an arbitrary user selected channel generally isn t in good thermal contact with the bottom of the PPMS sample chamber where the PPMS system thermometer is located The temperature of the user thermometer tends to drift over time in an unknown fashion This circumstance is the main reason for the complexity of the wizard algorithm To account for this effect the wizard offers two calibration modes that represent different tradeoffs between speed and accuracy e The fast mode assumes that the drift in the thermometer over the course of the entire set of field steps is actually linear It compensates by subtracting this b
11. a time between measurements of resistance you can add if you want a more extended sampling time User Thermometer The name of the 2D table file tab 2Dtable LogFileName The name of the data file dat Journal File The name of the journal file jrn Quantum Design PPMS Application Note 1078 202 B O 9 February 21 2006 Appendix B Magneto Resistance Calibration for the VSM Thermometer VSM Option uses the CAN Module for its thermometry 1t does not use the User Bridge on the Model 6000 Therefore the following modifications will need to be followed in order to use the Magneto Resistance Calibration Wizard with the VSM thermometer Hardware installation 1 Install the VSM coil set to be calibrated into the PPMS sample chamber and a baffle assembly without the charcoal holder The VSM head and Sample Tube are not necessary for this procedure 2 Connect the gray lemo resistivity cable between the gray lemo port on the back of the PPMS probe head and the P1 User Bridge on the Model 6000 Software Configuration 1 Open the Coil XXX cfg file located under QdPpms Vsm Calibration Copy Table 25 from the coil configuration file as indicated in Figure 6 and paste into a new Notepad page P Coil 064 cfe Notepad Fie Edit Format View Help coil Configuration File Table 25 Therm TABLE 25 2 2 0 l 42 60442 439 97808 46 16434 398 536758 530 15573 361 05463 54 64522 327 13100 59 70667 296 318 91 65 4059
12. arts it can put the PPMS in the same State it was before the interruption occurred Data file The data file is a log file the wizard creates so that you can see the progress of the calibration using MultiVu It is also helpful when diagnosing problems during calibration The data displayed in this file is not directly used in the creation of the tables It writes out the following fields e the PPMS block temperature which is always MR corrected e the apparent resistance of the user thermometer e the temperature reported by the user thermometer which is uncorrected during the calibration phase and magneto resistance calibrated during the verification phase e the magnetic field e the percent difference between the user thermometer readings at the current field and zero field Table files After finalizing the calibration phase the wizard writes out two files These files contain the Magneto Resistance calibration table or 2D table in two different formats e the tab file contains the table in a format that can be plotted using MultiVu or the Table2D program part of the PPMS utilities e the cfg file contains a sequence of PPMS commands that can be directly downloaded to the Model 6000 or included in the configuration file of some of the PPMS options such as ACMS or the horizontal rotator Quantum Design PPMS Application Note 1078 202 B O 3 February 21 2006 Interpreting the wizard s results Magneto resistance calibra
13. aseline from the apparent correction factors e The high accuracy mode only assumes that the drift in the user thermometer is linear over a single field step To compute the baseline it goes back to the previous field and measures the resistance value again It gets a measure of the drift over the much smaller single field step This mode takes substantially longer than the fast mode but it should produce a more reliable correction in situations where the value of the user temperature has substantial systematic variations Installing the wizard This procedure assumes that PPMS MultiVu has already been installed in the system 1 Load the installation disk into the control PC 2 Run setup exe and then follow the on screen instructions The MR Calibration Wizard and the configuration files are copied into the PC hard drive Quantum Design PPMS Application Note 1078 202 B O l February 21 2006 3 Start the wizard by double clicking the MagCalWizard icon Figure 1 from the directory chosen during installation or by iT MaacalWizard exe following the Programs gt Quantum Design gt b MRCalWizard link on the Windows Start button Figurel MagCalWizard icon Running the wizard 1 Provide the wizard with information The wizard requires some initial information on what you want to calibrate It guides you through the different options and runs automatically once you have provided all the required information There are two diff
14. e 6 Save the new changes for the thermometer configuration file Note Before using the Rotator option redownload the Rotator configuration file to the Model 6000 anytime you make changes to any of the option configuration files in order for the new changes to be sent to the Model 6000 The new magneto resistance calibrated Rotator 1s ready for use The procedures for installing and using the Rotator remain the same for the new calibrated option Quantum Design PPMS Application Note 1078 202 B 0 IS February 21 2006
15. ead from the Model 6000 MaxTemp MinTemp This is the maximum temperature that will be calibrated The wizard uses the sample chamber thermometer as a calibrated thermometer so there won t be any gain in raising this value if the block thermometer is not calibrated to that temperature as well The calibration table will actually extend beyond this temperature but only because it needs to set the correction to zero for the highest temperature This is the minimum temperature that will be calibrated This is usually a value lower than the temperature the PPMS will be able to reach Therefore the wizard waits some time to reach it The operation times out and the wizard sets what appears to be the lowest reachable and stable temperature MinTempVer Minimum temperature used during verification process Default is set to 1 9K CriticalHeLevel Because the wizard can take a long time to run the PPMS running out of helium and leaving the charged magnet exposed becomes a risk To avoid this situation the wizard checks the helium level before setting a new field brings the field back to zero and refuses to continue until the helium is replenished Only change this parameter if your helium level meter is configured in a non standard way Otherwise the default value of 50 is the minimum that can be used Nfields The number of field steps to take FieldDist Distribution of sample field 0 Quadratic 1 Linear
16. ed to the default settings for the wizard as it was shipped from Quantum Design They were selected to provide a reasonable compromise between speed and accuracy but might not work under all circumstances This is when the configuration file might prove valuable You can change the distribution and number of fields and temperatures to improve reliability Quantum Design does not recommend using less than seven points in the field or the temperature grid However more fields or temperatures should improve accuracy at the expense of a longer calibration run If the data seems to be particularly noisy you can increase the calibration readings or spread them over a longer sampling time You can also change the calibration mode The fast mode might be good enough after the system has been at low temperatures for several days Quantum Design PPMS Application Note 1078 202 B O 7 February 21 2006 Appendix A Description of the parameters in the configuration file Although the default settings are at the best settings and no changes are required you can change several parameters in the MRCalWizard ini configuration file if you want more control over the wizard Configuration file parameters Description MaxField The wizard reads the maximum field from the Model 6000 but if there is any special circumstance that prevents reaching the maximum value this value can be changed The default value of zero means that the value will be r
17. erent levels of input that you can provide the wizard e The top level general information is provided through the wizard graphical user interface You will have the opportunity to select what thermometer you want to calibrate and the wizard will assume default settings for its operation This makes it possible to quickly start calibrating with the minimum amount of knowledge about how the wizard actually works e On the other hand if more control is needed you can also change some of the parameters that the wizard uses such as time out values number of readings temperature and field ranges etc to modify its behavior Access these settings through the MRCalWizard ini configuration file It shouldn t be necessary to change the settings in this file unless you find that the default settings do not work in a particular case These settings are described in the Appendix A Choose the thermometer Once you have chosen the thermometer the wizard runs automatically and unattended Note If the helium level runs low the wizard stops sets the field to zero and waits for the dewar to replenish with liquid helium When the wizard detects a low helium level you can instruct it to continue setting fields until the next temperature set point Only do this if the level of liquid is enough for the magnet to remain superconducting until the field is ramped back to zero Otherwise the wizard will wait for some time before setting the field to zero and
18. for the Sample Transport The Sample Transport is not necessary in order to perform the calibration Refer to the ACMS Option User s Manual for detailed procedures for installation The ACMS thermometer calibration table is stored on Channel 25 and read on System Bridge 4 System Bridge 4 resistance values are reported on Channel 42 or Spare Therm Magneto Resistance Calibration Wizard For ACMS 1 Run the Magneto Resistance Calibration wizard 2 The wizard will ask for Auto or Manual Detection Select Auto Detection 3 You will then be prompted by the wizard to activate the option with the thermometer to be calibrated By activating the option the appropriate table will be downloaded to the Model 6000 and channel activated for the wizard to detect Select OK once you have activated the option Note When activating the ACMS option it is normal to get servo connection errors since the sample transport was not installed Select OK and allow the option to run in simulation mode The importance of activating the ACMS is the initialization of the coil thermometer 4 The wizard then detects and verifies the option thermometer is operating properly After checking the thermometer the wizard will let you know that it is ready to start MR calibrating the thermometer Before starting the calibration procedure the wizard recommends to deactivate the option that is being calibrated in order to prevent any interference that might occur between the opti
19. g used with the ACT System Bridge Channel 4 reads the rotator thermometer System Bridge 4 resistance values are reported on Channel 42 or Spare Therm However for the following procedure the ACT option will not be necessary Magneto Resistance Calibration Wizard For ACMS 1 Run the Magneto Resistance Calibration wizard 2 The wizard will ask for Auto or Manual Detection Select Auto Detection 3 You will then be prompted by the wizard to activate the option with the thermometer to be calibrated Download the rotator configuration file to the Model 6000 using RomC gf32 exe if you have not already done so Select OK once you have downloaded the file 4 The wizard then detects and verifies the option thermometer is operating properly After checking the thermometer the wizard will let you know that it is ready to start MR calibrating the thermometer Ignore the recommendation to deactivate the option it does no apply to the rotator option and select OK 5 The Magneto Resistance Calibration Wizard will then run the calibration automatically Proceed to the next step once the verification process of the Magneto Resistance Calibration Wizard is complete Updating the Rotator cfg File With the New MR Calibration 4 Open the new MR calibrated cfg file located under OdPpms Tools Figure 14 2DTable_HR cfe Notepad Mima File Edit Format View Help Thl dHex 1 23 2 2 3 1 1 20 20 0 3EF9FSC13F21CF B3F46A2 95 SF6B AS6405DF 5 36AB
20. on and the calibration wizard Once the option is deactivated select OK 5 The Magneto Resistance Calibration Wizard will then run the calibration automatically Proceed to the next step once the verification process of the Magneto Resistance Calibration Wizard is complete Updating the ACMS Thermometer cfg File With the New MR Calibration 1 Open the new MR calibrated cfg file located under QdPpms Tools Figure 12 2DTable_ACMS cfe Notepad Mima File Edit Format View Help Thl dHex 1 25 2 2 3 1 1 20 20 0 3F6A5 74F3F846E693F935B12B3FAz ABY939 0S8BYEOSFYBBAUY 2 SCABADZ OBS BYSHCE I DS9BC2D92 3AADDEG SBS SBASBBY4SBAD SOALBADAE SO0BAs S0948BA9 52 SBI BAYOL4ASFBASBEB4ADZBA SL 33 C5C4BD2D28FE1L03 COLESERS8BCBF41 5942E981599 9sSBR sYCLBOBFS9C TBLMODE 25 2 gt Figure 12 MR calibrated configuration file for the ACMS Quantum Design PPMS Application Note 1078 202 B O 15 February 21 2006 2 Copy the 2D table from the configuration file and paste in the ACMS Therm XXX cfg file OdPpms ACMS Calibration under the original thermometer calibration table Ensure to also include the command TBLMODE 25 2 when copying the table over to the thermometer configuration file Figure 13 Thrm 025 cfe Notepad File Edit Format View Help Original Calibration Table TABLE 25 2 2 0 38 73050 447 aleg 42 395316 400 28341 46 5475 QO 137668 82000 2 49473 702267 63000 da 25976 s01b 74 41000 2U Thl2dHex
21. ratio after image effect calibration Image RRR 54 change the image RRR after image effect calibration shrinkage Coeff 0 98 calibrated sept 5 on sample chamber SCE 432 Delay 000100 change the delay after coil calibration Amplitude Calibration 1 1 5 9996 1 1 1 5 9959 2 9878 2 5 9750 3 9534 3 5 9235 10 1 change this list of amplitude correction factor after amplitude calibration Figure 6 VSM coil configuration file Quantum Design PPMS Application Note 1078 202 B 0 10 February 21 2006 2 4 Add the following commands at the bottom of the new configuration file containing only table 25 Figure 7 Mapdat 25 4 lt lt Maps data to Bridge 1 on the User Bridge Tblmod 25 1 lt lt Activates Channel 25 Save the new file as a cfg VSM therm on chi for MRCal cfg Notepad File Edit Format View Help TABLE 25 2 2 0 A 4 60442 459 07808 46 16434 398 536758 50 15573 361 05463 534 56 4522 327 13100 59 70667 296 31891 65 40599 268 25333 71l 78219 if P9159 786 90714 219 67096 86 80920 198 766003 95 534186 179 289692 TO5 14400 162 86740 1115 73087 147 41000 127 31784 1353 47711 1490 0560 1220 83331 154 06384 109 s445 7 169 35099 98 95 165 186 22914 89 499900 204 627 78 80 96085 2244 86615 73 222r 24r 04158 66 23361 271 48741 59 8786653 207 92195 54 27571 327 H060 4S 936860 359 70259 44 27373 3905 13034 40 03310 433 7097
22. t temperature to make sure that the irregularity is actually produced by a temperature change and not a problem in the calibration Looking at the actual table file One of the tools shipped with PPMS MultiVu is the Table2D program Use this program to load the current MR calibration table directly from the PPMS To read the generated tab file click File gt Load 2D tab Format on the PPMS MultiVu main toolbar You can see the actual values of the MR corrections and plot them against field Figure 4 or temperature Figure 5 Field Correction Table Viewer Figure 4 A typical calibration table plotted against Field Quantum Design PPMS Application Note 1078 202 B O 6 February 21 2006 Field Correction T able Viewer Figure 5 A typical calibration table plotted against Temperature Notes on Figure 4 and Figure 5 e The corrections become zero both at 20K and O Tesla e The maximum correction might not happen at the lowest temperature because the oscillatory magneto resistance mandates a node in the correction value at that point e The tables should look smooth Sudden jumps in the corrections versus field or versus temperature might indicate that the wizard failed to successfully calibrate your thermometer What to do if the calibration fails to produce an usable table Sometimes the wizard might not provide an adequate calibration and or the residual errors are considered to be too large This might be attribut
23. t trying to get to the lowest temperature possible e The temperature error during the calibration phase was around 1 for large fields This is the normal order of magnitude for Cernox thermometers shipped with the Quantum Design systems below 10K and above 1 8K In 14 Tesla systems it might be up to 5 for the lowest temperature e After calibration the errors should be 0 1 0 2 but the data file might report errors that are larger than that The user thermometer not being actively controlled or the ACMS coil set or rotator thermometers in poor contact with the PPMS block at the bottom of the sample chamber are factors that attribute to possible larger errors on the data file Therefore changes in the heating or cooling power needed to keep the PPMS block at a constant temperature might produce actual temperature changes in the user thermometer Usually it is easy to tell that this 1s the case e Figure 3 zoomed in on the verification at 2 5K on the System Temperature User Temperature shown in Figure 1 You can see that the temperature error failed to come back to zero after the field was ramped back down to zero The effect of Eddy currents heating had time to Quantum Design PPMS Application Note 1078 202 B O 5 February 21 2006 dissipate The step like nature of those changes also indicates some real temperature changes as temperature corrections are smoothly introduced e The software will automatically repeat the verification at tha
24. ter Similar to the VSM Option in order to use the Magneto Resistance Calibration Wizard to calibrate the thermometers on the TTO puck some specific procedures need to be followed In addition the Hot and Cold thermometers have to be calibrated separately The Hot thermometer calibration table is stored on Channel 21 and read on User Bridge Channel 1 The Cold thermometer calibration table is stored on Channel 22 and read on User Bridge Channel 2 Hardware set up l Mount a Copper mounting bridge assembly 4084 608 sample supplied in your TTO user kit Connect the TTO heater and thermometer shoes to it This copper sample thermally shorts the TTO shoes to the puck 2 Install the puck and a baffle assembly without the charcoal holder into the sample chamber Attach the appropriate TTO gray lemo cable and other required cable connections as discussed in Appendix A 2 Installing Thermal Transport Hardware of the TTO User s Manual Activate the TTO Option This will send the proper thermometer calibration tables to the Model 6000 Before starting the MR Calibration Wizard deactivate the TTO option in order to prevent any interference that might occur between the option and the calibration wizard Magneto Resistance Calibration Wizard For TTO l 2 Run the Magneto Resistance Calibration wizard The wizard will ask for Auto or Manual Detection Select Manual Detection 3 Then select which bridge channel to calibrate
25. tion of a thermometer that is not in good thermal contact with the reference being used 1s a difficult procedure which requires careful interpretation of the results Because sudden jumps in temperature might be traced back to flow changes for example Quantum Design suggests that you log diagnostics PPMS data by clicking Utilities gt Log PPMS Data on the PPMS MultiVu main toolbar First look at the data file and then look at the actual table file Looking at the data file After a successful run the data file should look like the example in Figure 2 ME PPMS Hulti u HRCa izard _ 4 dat pleje ele Hle 2 Magneto Resistance thermometer calibration a se 1 a e w J 5 H Lt Z a w Fo ue e g e EL mi ti in I in Magnetic Field Gauss Temperature Error 1i Time minutes rel ati wre Figure 2 Example of the wizard s data file Quantum Design PPMS Application Note 1078 202 B O 4 February 21 2006 E Multi u HR Ca izard_4 dat Plejaj ele e a u u e 2 Magneto Resistance thermometer calibratian User Temperature K a 5 T L T a E a He E a Th an Magnetic Field Gauss Temperature Error 0 rri Time minutes relati we Figure 3 A closer look at System Temperature User Temperature from Figure 1 Notes about Figure 2 and Figure 3 e Calibration on the last temperature started only after a long wait This is normal The wizard is jus
26. waiting The wizard begins to calibrate It calibrates with the highest temperature first and ends at the lowest achievable temperature The fast mode or the high accuracy mode steps up the field for each temperature Once the calibration is finished the magneto resistance calibration table is computed written and sent to the Model 6000 controller The verification phase starts It starts with the lowest temperature In this mode the field is slowly ramped up to full field and the deviations from the zero field user temperature are reported in the data file The user temperature actually drifting away attributes to part of the deviations although even with this drift the deviations are small The maximum deviation for each temperature is also written to the journal file Quantum Design PPMS Application Note 1078 202 B O 2 February 21 2006 The wizard s output files Upon completion the wizard has created several files and changed the state of your PPMS in several ways Journal file The wizard keeps its memory in the journal file If the wizard is aborted in the middle of a calibration or if there 1s a software hardware failure the journal file helps the wizard figure where to start from when it is restarted It keeps the calibration data for each temperature so that it can reconstruct the calibration tables up to the point where it left them It keeps a copy of the bridge settings channel mappings and tables so that once it st
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