Hit Chemical - Tristan Technologies, Inc.
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1. is not normally applicable to the 703G system but is relevant if you are performing other tests Run the TUNE Utility Heat for about 3 seconds then pause for 2 minutes If the SQUID does not go normal as seen by observing the triangles as described in the User s Page 19 of 23 Manual for iMAG HTS Multi Channel dc SQUID System you may increase the heat time in small increments until the SQUID goes normal If the heat time becomes excessively long contact Tristan or your local distributor for advice before proceeding Run the TUNE Utility When turning off the system set Bias and Mod and Skew to 0 disconnect the CC 6 composite cable s and then turn off AC power When disconnecting all cables disconnect the 5 pin LEMO connector first then the 10 pin LEMO connector Page 20 of 232. CES CLEAN TO PREVENT COMBUSTION Atmospheric air will condense on exposed nitrogen cooled piping Nitrogen having a lower boiling point than oxygen will evaporate first from condensed air leaving an oxygen enriched liquid that may drip or flow to nearby surfaces Areas and surfaces upon which oxygen enriched liquid can form or come in contact with must be cleaned to oxygen clean standards to prevent possible ignition of grease oil or other combustible substances Leak testing solutions should be selected carefully to avoid mixtures which can leave a residue that is combustible When combustible type foam insulations are used they should be carefully applied to reduce the possibility of exposure to oxygen enriched liquid which could upon impact cause explosive burning of the foam CAUTION DO NOT MAKE ANY MODIFICATIONS TO THIS SYSTEM WHICH MIGHT AFFECT ITS ABILITY TO VENT NITROGEN GAS IN THE EVENT OF AN EMERGENCY SUCH AS LOSS OF VACUUM IN THE DEWAR VACUUM SPACE 2 4 4 KEEP EQUIPMENT AREA WELL VENTILATED Although nitrogen is nontoxic it can cause asphyxiation in a confined area without adequate ventilation Any atmosphere which does not contain enough oxygen for breathing can cause dizziness unconsciousness or even death Nitrogen being colorless odorless and tasteless cannot be detected by the human senses and will be inhaled normally as if it were air Without adequate ventilation the expanding nitrogen can displace air and re
3. E 7 5040325 NOISE MEASURED TRISTAN ccssscsccccecsessstcecececsesseaeseccceceessaecesececeeseaeseseesceesenssaeeeeees 8 FIGURE 8 NLD 530 DEWAR DIMENSIONS INCHES 10 FIGURE 9 INDI536G PROBE A aa NA E ngahad dine caes 11 FIGURE 10 GRADIOMETER ORIENTATION cceesssseeecececsesseaececececsesneaeceecceceeeaaesecececsessaasceeececeeseaaeseeeeeeseneaeea 11 FIGURE 11 SHUNTING PICU GS Ag Pee Tees aga NAN hieme ttam aes Vm eeu 18 FIGURE 12 SILICA GEE INDICATOR COLORS aa EE E e eec E Te eee e Subs e eee cubs 18 TABLE OF TABLES TABLE 1 DEWAR TEST REPORT RESULTS restet ere eret eres tees eee pepe eta eure Pee TENE 9 1 WARRANTY Tristan Technologies Inc warrants its products to be free from defects in material and workmanship Obligations under this warranty shall be limited to replacing repairing or giving credit for the purchase price at Tristan s option of any instrument returned shipment prepaid to its factory for that purpose within one year of delivery to the original purchaser provided prior authorization for such return has been given by an authorized Tristan representative This warranty shall not apply to any instrument which Tristan s inspection discloses to have become defective or unworkable due to abuse mishandling misuse accident alteration negligence improper installation or other causes This warranty sha
4. TY PRECAUTIONS dee eerte tree e b tie pH in ae 11 2 5 USE OFLIQUID NITROGEN 2 eene eh eee ee A E 12 ANSTALLATION 12 3 1 INITIAL INSPECTION eee iet paga et edet 13 3 2 NORMAL INSTALLATION trio rete er RH ed MERE 13 4 NORMAL OPERATION ccssssssssssssessssessessesessessssessessssessessssessessesessessesessessssesesesessesseseeessesessesseses 14 4 1 REFILLING THE DEWAR WITH LIQUID NITROGEN 14 4 2 WARM UP PROCEDUR P oeh ene TR dae 14 5 TROUBLE SHOOTING ou cssssssssssessersesessersesessersssessessesessessssessessesessessesessessesessessesesessesessessesessessesess 15 OMMBUENOnrnn 16 6 1 DEWAR VAGUUM reel tete tend a ec E e e t tere e on 16 6 2 HIGH TEMPERATURE SQUID SENSOR ADVISORY eee eene nennen 17 TABLE OF FIGURES FIGURE 1 7036 SYSTEM COMPONENTS 5 E a aa a NG La a a BE nani a seen nete Ka sessi ta sess La ag a ga a a a Gn 2 FIGURE 2 5340323 SENSITIVILY LP ba a a Ba a aa a 3 FIGURE 3 5540324 SENSITIVITY PE a a A aaa A Aa E na 4 FIGURE 4 5G40325 5 aa aei cei eee NG BE ted tee e itd eo e aa 4 FIGURE 5 SG40323 NOISE MEASURED AT TRISTAN ccssscsccccecsesssececececsessaececcceceesesecesececeeseaeaeeeesceesenssaeseeees 6 FIGURE 6 5040324 NOISE MEASURED AT TRISTAN ccssccccccecsessssececececseseeceeceeceesenssaeeeesceesesaaeseeeceesenssaeeeeess 7 FIGUR
5. User s Manual for model 703G HTS SQUID multi channel Gradiometer System dBz dy dBz dx Tristan Technologies Inc San Diego California USA O copyright 1999 Tristan Part Number 3000 120 Revision Record Bem April 1 1999 Initial Release July 28 2003 B Product Update June 21 2004 Product Update 1998 2004 by Tristan Technologies Inc All rights reserved No part of this manual may be reproduced stored in a retrieval system or transmitted in any form or by any means electronic mechanical photocopying recording or otherwise without prior written permission of Tristan Tristan reserves the right to change the functions features or specifications of its products at any time without notice Any questions or comments in regard to this product and other products from Tristan please contact Customer Service Tristan Technologies Inc 6191 Cornerstone Court East Suite 107 San Diego CA 92121 USA Phone 858 550 2700 FAX 858 550 2799 info1 tristantech com http www tristantech com TABLE OF CONTENTS E n 1 2 GENERAL INFORMATION eeeeeee eene en enses tatus ots ta sustain inse 059955 059590057995 65959 00506905794565 2 2 1 INTRODUCTION irte e RH RP eger M 2 2 2 SYSTEM COMPONENTS e rS puede o ten pee irte bets Pme RUE ENS 2 2 3 MEASURED PARAMETERS AND FACTORY TEST DATA sees 3 24 SAEE
6. aks Skew 28 72 5 V fT cm Hz Cooling time 20 min Heating time above Ta 7 sec Figure 4 5040325 Sensitivity White Noise measured at 100 Hz 33 fT cmVHz noise at 1 Hz 85 fT cmNHz 2 3 1 1 Measurements in a non superconducting shield Additional measurements were made at Tristan in a MS 830 three layer non superconducting mu metal shield 5 5 i d These tests determine the bandwidth and voltage transfer function for each device Operation at various gains and ranges are verified using the customer s electronics Testing is done using Hewlett Packard 34401A DMM 35665A dynamic signal analyzer and other appropriate test Page 4 of 23 equipment Typically multiple average FFT s are taking using Hanning window to give the spectra shown below Because of the local environmental noise these measurements Figure 5 Figure 7 show different noise levels than the results shown in figures 1 3 channel 1 22 vs 32 fT cmYHz shielded channel 2 100 vs 25 fT cm Hz shielded channel 1 58 vs 33 fT cmNHz shielded Channel 2 s higher noise may be due to its vertical orientation in the mu metal shield These tests were not to demonstrate ultimate performance in a remote environment but to verify proper operation of the SQUID electronics higher noise is typical of unshielded operation Reducing external noise contributions can be very difficult In gradiometers especially in a laboratory environment significant noise c
7. an be introduced if the dewar is positioned near a metal fixture Section 5 discusses ways to reduce the influence of environmental noise sources Page 5 of 23 96252 2 SHZ Date 84 29 84 Time 18 15 88 1 024 2 98 1661 9 Y dBVrms rtHz dB Mag 4 dB div x VEU Lap K 256Hz 666 i82 4kHz Figure 5 5640323 noise measured at Tristan Test configuration SQUID Controller used iMC 303 S N 1093 Flux locked Loop used iFL 301 H S N 2061 SQUID sensor used S N SG40323 System Channel 1 Test Setup Gain x100 Slew Normal Heater Test Heat Time 9 sec Cool gt 99 sec Autotune Triangle Amplitude 2 Vpeak to peak Tune Parameters Bias 18 Bias 18 Mod 18 Skew 23 Gain X100 X100 X50 units Slew Normal Slow Normal 0 52 N A N A Noise 1 kHz 22 N A N A fT cmNHz Bandwidth 3 N A N A kHz Loop Locked yes yes yes N A Page 6 of 23 96252 2 SH2 bate 84 29 04 Time 12 35 88 PH A X 1 8024 kHz 85 4583 Y dBVrms rtHz dB Mag TUESIU div 738 E Nei NJ ka M 168 256H2 Ave 547 102 4kHz Figure 6 5040324 noise measured at Tristan Test configuration SQUID Controller used iMC 303 S N 1093 Flux locked Loop used iFL 301 H S N 2062 SQUID sensor used S N SG40324 System Channel 2 Test Setup Gain x100 Slew Normal Heater Test Heat Time 15 sec Cool gt 99 sec Auto
8. ed it will be necessary to make sure that any water which condenses in the dewar is removed prior to using the Page 14 of 23 system again This can be done by wiping it out using on the end of a rod or by blowing room temperature air into the tail of the dewar WARNING DO NOT BLOW HOT AIR INTO THE DEWAR AS THIS MAY CAUSE FAILURE OF THE EPOXIED JOINTS 5 TROUBLE SHOOTING The greatest obstacle to SQUID measurements is external noise sources Metallic shielding can minimize external noise e g act as a low pass eddy current shield In the case of HTS SQUID sensors the use of high permeability mu metal shields such as the Tristan MS 830 can significantly attenuate external field variations This assumes that any electrical inputs to the experimental region have been appropriately filtered Powerline or microprocessor clock frequencies can severely degrade performance Unfortunately if external objects are to be measured external shields are not appropriate However external shields are helpful in verifying proper operation of the SQUID system and electronics When measuring external fields the SQUID magnetometer must operate in an environment the magnetic field of the earth that can be 10 orders of magnitude greater than its sensitivity The magnetic field at the surface of the earth is generated by a number of sources There exists a background field of 50 uT with a daily variation of 0 1 uT In addition t
9. eled to indicate which connector corresponds to which sensor 2 Wynn W Frahm C Carrol P Clark R Welhoner J and Wynn M Advanced Superconducting Gradiometer Magnetometer Arrays and a Novel Signal Processing Technique IEEE Transactions on Magnetics 11 pp 701 707 1975 Page 10 of 23 dBz dy dBz dx Figure 9 NLI 53G Probe Figure 10 shows the layout of the three HTS planar gradiometer SQUID sensors C gt By Z dB dy Y X Ho Figure 10 Gradiometer Orientation 2 3 4 Electronics and software See the Users Manual for iMAG HTS Multi Channel SQUID System for information on the use of the electronics and software 2 4 SAFETY PRECAUTIONS 2 4 1 SAFETY PRECAUTIONS FOR HANDLING LIQUID NITROGEN The potential hazards of handling liquid nitrogen stem mainly from the following properties 1 The liquid is extremely cold 2 The ultra low temperature of liquid nitrogen can condense and solidify air 3 Very small amounts of liquid nitrogen are converted into large volumes of gas 4 Nitrogen is not life supporting 2 4 2 EXTREME COLD COVER EYES AND EXPOSED SKIN Page 11 of 23 Accidental contact of liquid nitrogen or the cold gas results from its rapid evaporation may cause a freezing injury similar to a burn Protect your eyes and cover the skin where the possibility of contact exists Eye protection should always be worn when transferring liquid nitrogen 2 4 3 KEEP EXTERIOR SURFA
10. he range Do not heat the SQUID using HEAT button on the Tristan model iMC 303 SQUID Control Electronics or equivalent heating circuit at when the SQUID sensor is at room temperature Ship the SQUID sensor with the shunting plug attached and in a closed container with desiccant inside NEVER allow the SQUID to sit in a sealed dewar with water condensed on the bottom WARNING MOISTURE DAMAGE DUE TO FAILURE TO FOLLOW THESE INSTRUCTIONS WILL VOID THE WARRANTY HTS Sensor Cool Down and Usage Do not touch the pins or connector of the SQUID Observe ESD precautions when connecting the SQUID s cables Do not measure SQUID cable resistances when cold Initial cool down of the SQUID is with the Tristan iFL 301 H flux locked loop electronics connected to the LEMO connectors at the top of the cryostat However do not yet connect the CC 6 composite cable s to the iFL 303 H Flux Lock Loop s Connect the CC 6 composite cable s to the Tristan model iMC 303 SQUID Control Electronics first Turn on the Tristan electronics with the SQUID not connected Go to SETUP MANUAL TUNING ENTER and then reduce Bias Mod and Skew to 0 Allow the SQUID electronics to stabilize for 10 minutes Connect the CC 6 composite cable s at the Flux Lock Loop first then connect 10 pin LEMO connector and then connect the 5 pin LEMO connector last If the SQUID is in a vacuum verify that the correct heater current limits are in place This
11. here is a contribution below 1 Hz from the interaction of the solar wind with the magnetosphere The remaining contributions to external magnetic fields are primarily man made These can be caused by structural steel and other localized magnetic materials such as furniture and instruments that distort the earth s field and result in field gradients moving vehicles that generate transient fields electric motors elevators radio television and microwave transmitters and the ever present powerline electromagnetic field and its harmonics It is highly advisable to perform initial tests in a magnetically shielded environment If you do not have a shielded room measurements made after midnight or on the weekend can be compared to measurements during the day to see if there are environmental effects If rfi is of concern wrapping the dewar in aluminum foil may improve the situation This acts as an eddy current shield While it may reduce the system s bandwidth depending on the amount of aluminum foil used and perhaps increase the system s white noise it can be very effective in attenuating rfi As mentioned above significant gradient noise can be introduced if the dewar is positioned near a metal fixture such as a steel filing cabinet or a power distribution box If a planar gradiometer is being tested rotating the gradiometer anywhere from 302 902 can often make a significant change in the measured gradient noise During the initial testi
12. ld be slowly vented over a period of about 15 minutes The nitrogen reservoir must always be at room temperature when gas is admitted to the vacuum space or when it is being pumped The dewar is equipped with a vacuum space evacuation valve mounted on the dewar top Before opening this valve a leak tight connection should be made to it and the pumping line to the valve should be evacuated using a leak detector or a pumping station equipped with a diffusion pump and cold trap or other pumping system with equivalent capability The cold trap is necessary to prevent back streaming of pump oil into the vacuum space after it has reached a low static pressure WARNING OPEN THE VALVE VERY SLOWLY AND OBSERVE THE PRESSURE IN THE DEWAR DO NOT BEGIN PUMPING UNTIL YOU OBSERVE THE PRESSURE If you observe a high pressure more than a few torr you should pump the vacuum space very slowly by opening the valve as little as possible Page 16 of 23 A satisfactory vacuum is about 100 200 millitorr when the whole dewar is room temperature Depending on the pressure it may take up to 24 hours to obtain a satisfactory pressure WARNING DO NOT LEAVE THE DEWAR PUMPING UNATTENDED Since most of the time required is for outgassing of the surfaces in the dewar it is better to pump the dewar for 15 minutes every few hours There is little advantage to leave the pump connected continuously If you suspect that there is water or other con
13. ll not apply to any instrument or component not manufactured by Tristan When products manufactured by others are included in Tristan s equipment the original manufacturer s warranty if any is extended to purchaser to the extent permitted by that manufacturer Tristan reserves the right to make changes in design at any time without incurring any obligation to install same on units previously purchased There are no warranties which extend beyond the description herein This warranty is in lieu of and excludes any and all other warranties or representations expressed implied or statutory including merchantability and fitness for purpose as well as any and all other obligations or liabilities of seller including but not limited to special or consequential damages No person firm or corporation is authorized to assume for Tristan any additional obligation or liability not expressly provided for herein Page 1 of 23 2 GENERAL INFORMATION 2 1 INTRODUCTION This instruction manual contains installation operation and maintenance instructions for the model 703G HTS SQUID gradiometer measurement system supplied by Tristan Technologies Inc A schematic of the system is included for reference as Figure 1 CC 6 composite cables iFL 301 H flux locked loops iMC 303 SQUID Control Electronics NLD 530 Dewar Figure 1 703G sys
14. ly via boil off To refill a cold dewar remove the fill tube plug and install the provided funnel into the fill tube Slowly pour LN into the funnel until LN vents from the vent port Wait a moment and then add more until it again vents from the vent port Repeat this sequence until adding liquid causes immediate venting The dewar is now filled Remove the funnel and replace it with the fill tube plug 4 2 WARM UP PROCEDURE If the SQUID magnetometer probe is not in the dewar then pouring out the liquid nitrogen or letting the liquid nitrogen evaporate is acceptable However since HTS SQUID sensors will be damaged by exposure to moisture section 6 2 special precautions must be taken when warming up dewars that are being used to cool HTS SQUIDs To prevent exposure to moisture immediately remove the probe and place the probe inside a tight fitting plastic bag to prevent excessive condensation of moisture Be sure that a desiccant is inside the bag When the probe and sensors have warmed up to room temperature place the probe in a moisture free container e g a dry box After removing the probe turn the dewar upside down to pour out the remaining nitrogen Be sure not to pour the liquid nitrogen on anything that could be damaged Then let the dewar warm up to room temperature leave the neck tube open Turning the dewar upside down will minimize the amount of moisture that may condense inside the dewar If this procedure is us
15. ng be sure that the system is on a sturdy platform A flimsy table may cause motion induced noise Also be sure that the platform or whatever mounting is being used is free of any ferromagnetic contaminants Avoid using conductive metal tables as they can couple in gradient noise Page 15 of 23 6 MAINTENANCE 6 1 DEWAR VACUUM Prior to cooling down especially if the dewar has been at room temperature for a long period of time the dewar vacuum should be checked to verify that the vacuum space is evacuated Eventually the vacuum space of the dewar will need to be re evacuated This will become obvious in one of two ways e The nitrogen evaporation rate will increase during normal operation If the evaporation rate has increased by more than 3095 you should consider re pumping the vacuum space e You will be unable to transfer liquid nitrogen All of the nitrogen transferred into the dewar will immediately evaporate If the vacuum is extremely poor the outside of the dewar may get cold and even condense water especially along the tail If you suspect a poor vacuum use the following procedure to check and pump on the vacuum WARNING EXTREME caution must be used when examining the vacuum There are many fine layers of superinsulation in the vacuum space Rapid changes in pressure may cause rupturing of the superinsulation Therefore NEVER abruptly open the dewar vacuum space to atmospheric pressure the dewar vacuum shou
16. onnect the shunting plug at the top connector when the SQUID is not in use for extended periods and always for shipment See Figure 11 Page 17 of 23 Shunting plug e side view MM r Shunting plug SQUID with end view SQUID without shunting plug installed shunting plug installed Figure 11 Shunting Plugs Be sure to install shunting plugs on the connector of the SQUID when it is not in use for extended periods or during shipping Store the SQUID sensor in a moisture free environment by using desiccant in conjunction with a closed container This is especially important in humid or damp environments Typically desiccant Silica Gel appears blue when active and red or pink when saturated with moisture See Figure 12 Figure 12 Silica Gel Indicator Colors A Blue color indicates that the desiccant is still active A Red color indicates that the desiccant should be replaced When warming the SQUID sensor immediately place the SQUID sensor in a plastic bag when it is removed from the cryogen to minimize the condensation of water vapor on the cold surfaces After the SQUID sensor Page 18 of 23 reaches room temperature dry the body of the SQUID sensor Probe observing ESD precautions and then store with desiccant When testing the SQUID cables at room temperature limit the current by using a manual range on a low current digital multi meter Do not use the auto range function of the digital multi meter Select t
17. ratory but small differences are to be expected 2 3 4 SQUID sensors SQUID sensors are initially tested in a HTS superconducting shield to eliminate external environmental noise contributions The HTS shield is inside a multiple layer mu metal shield to ensure that the ambient field is minimized Testing is done using Tristan iMAG 300 SQUID electronics The flux transfer function and noise fT cm Hz are determined for each sensor The test results of the supplied SQUID sensors are shown below as a function of frequency The white noise guaranteed to be lt 70 fT cmYHz was measured at 100 Hz and are listed below each respective graph along with sensitivity at 1 Hz not a guaranteed value but shown for informational purposes 8G40323 24 cm gt e e e 0 91 Bias 81 Mod 4 9peaks Skew 190 Vy 1 5 V Hz Cooling time 20 min Heating time above T 7 sec Figure 2 5640323 Sensitivity White Noise measured at 100 Hz 32 fT cmNHz noise at 1 Hz 72 fT cmNHz Page 3 of 23 5040324 20 gt e e e 0 98 nT cm Bias 31 Mod 12 8peaks Skew 6 Vy 722 V fT cm VHz Cooling time 20 min Heating time above Te 7 sec Figure 3 5040324 Sensitivity White Noise measured at 100 Hz 25 fT cmNHz noise at 1 Hz 60 fT cmNHz 8G40325 20 cm gt icd 0 94 nT em Nn Bias 50 Mod 3 7pe
18. rn the unit for repair along with a tag to it identifying yourself as the owner Please enclose a letter describing the problem in as much detail as possible 3 1 1 REPACKING FOR RETURN SHIPMENT If it is necessary to return the system you should repack the unit in its original container if available For this reason it is advisable to save the original crate sent by Tristan however if this is not possible use the following instructions for repacking 1 Wrap the unit in either bubblewrap or foam rubber 2 Cover the bottom of a sturdy container with at least 3 inches of Styrofoam pellets or shredded paper 3 Set the unit down onto the packing material and fill the rest of the container with Styrofoam or shredded paper The unit must be completely protected by at least 3 inches of packing material on all sides 3 1 2 RETURN FROM CUSTOMERS OUTSIDE THE USA To avoid delays in Customs clearance of equipment being returned contact the Tristan representative in your area or the Tristan factory in San Diego California for complete shipping information and necessary customs requirements Failure to do so can result in significant delays 3 2 NORMAL INSTALLATION 3 2 1 COOLING THE SYSTEM FROM ROOM TEMPERATURE Install the funnel in the neck of the dewar Fill the dewar by slowly adding LN until half full This could take a few minutes Remove the funnel and slowly lower the probe into the dewar If liquid nitrogen bubbles or spurts o
19. ruction Figure 8 is that of a vacuum insulated vessel with the outer case constructed of G 10 fiberglass superinsulation in the vacuum space to reduce blackbody radiation and inner vessel also G 10 construction that acts as the nitrogen reservoir Volume 1 19 Liters Boil off no probe 0 30 L Day Hold Time no probe 4 Days Boil off with probe 0 36 L Day Hold Time no probe 9 Days Weight Empty 1 42 kg Weight Full no probe 2 23 kg Dewar Tail Gap 0 12 inches approximate 3 mm Table 1 Dewar Test Report Results Page 9 of 23 11 75 298 45 04 1 02 J 50 12 70 J Figure 8 NLD 530 dewar dimensions inches mm 2 3 3 Probe configuration Knowledge of the total magnetic field gradient VB of an object can allow determination of its magnitude and direction OB OB OB 0B Ox ae z OB OB B B 0B OX OB OB GB Oz Oz From Maxwell s Equations four of the gradients are redundant Thus only five gradient components are necessary to determine VH as shown above The model 703G 3 channel SQUID gradiometer was designed to measure the three unique planar gradients n b dBz dy dB dz dB dy dB dx and dBz dx dB dz The insert probe is shown in Figure 9 The three LEMO connectors on the top of the insert are lab
20. sult in an atmosphere that is not life supporting The cloudy vapor that appears when liquid nitrogen is exposed to the air is condensed moisture not the gas itself The issuing nitrogen gas is invisible Liquid containers should be stored in large well ventilated areas If a person becomes groggy or loses consciousness when working around nitrogen get them to a well ventilated area immediately If breathing has stopped apply artificial respiration If a person loses consciousness summon a physician immediately 2 5 USE OF LIQUID NITROGEN This system is designed for use ONLY with liquid nitrogen Instructions for precooling the probe and dewar are given in Section 3 2 1 of this manual 3 INSTALLATION Page 12 of 23 3 1 INITIAL INSPECTION All Tristan instruments and equipment are carefully inspected and packaged at Tristan prior to shipment However if a unit is received mechanically damaged notify the carrier and the nearest Tristan representative or the factory in San Diego California Keep the shipping container and packing material for the carrier and insurance inspections If the unit does not appear to be damaged but does not operate to specifications contact the nearest Tristan representative or the Tristan factory and describe the problem in detail Please be prepared to discuss all surrounding circumstances including installation and connection detail After obtaining authorization from the Tristan representative retu
21. taminants in the vacuum space it may be advantageous to flush the vacuum space with nitrogen gas Slowly fill the vacuum space with 10 torr of nitrogen gas this should not be done at a rate faster than 1 torr per minute It should then be re evacuated as described above This procedure may be repeated several times WARNING THE PRESSURE IN THE VACUUM SPACE MUST NEVER BE ALLOWED TO CHANGE QUICKLY RAPID PRESSURE CHANGES WILL CAUSE PERMANENT DAMAGE TO THE THERMAL SHIELD AND SUPERINSULATION If the dewar does not perform well after pumping the vacuum or if it requires pumping at intervals more frequent than once a year there may be a leak in the dewar If you suspect this problem contact your Tristan representative for assistance 6 2 HIGH TEMPERATURE SQUID SENSOR ADVISORY In order to insure optimum performance for your Tristan High Temperature SQUID system the following handling precautions should be followed Carefully adhering to these procedures will allow your instrument to function accurately for the duration of the warranty period and beyond Please feel free to contact Tristan with any questions 6 2 1 Handling for Shipping and or Storing at Room Temperature 5010105 are electro static discharge ESD sensitive devices Always store them in appropriate ESD safe packaging Use appropriate static sensitive handling equipment such as ESD mats and wrist straps when handling and connecting High Temperature SQUIDs C
22. tem components 2 2 SYSTEM COMPONENTS Please check the enclosed packing list carefully when unpacking the equipment to verify that everything is present and undamaged We recommend that you save the shipping crates for possible future use in case the system has been damaged and needs to be repaired 2 2 1 List of system components e Model iMC 303 iMAG SQUID Control Electronics S N 1093 Model iFL 301 H iMAG Flux Locked Loops 3 S N 2061 S N 2062 S N 2064 Model NLD 530 liquid nitrogen dewar S N 141 LN filling funnel Model NL 53G 3 channel SQUID probe S N 146 Model HTG 10R planar SQUID gradiometers 3 S N4 5640323 dBz dy S N4 5040324 dB dy S N 5840325 dB7dx iMAG is a Registered Trademark of Tristan Technologies Inc All Rights Reserved Page 2 of 23 e Model CC 6 six meter composite cables 3 e Power Cord HTS iMAG User s Manual and Applications Disk The country of origin for all components is the United States with the exception of the HTG 10R SQUID sensors whose country of origin is Germany 2 3 MEASURED PARAMETERS AND FACTORY TEST DATA The following parameters were measured at Tristan prior to shipment Dimensions and weights are approximate and are given for reference only Performance data is the result of testing done at Tristan Boil off tests values were taken after thermal equilibrium was established Under ideal conditions you should expect to achieve similar performance in your labo
23. tune Triangle Amplitude Tune Parameters 0 8 V peak to peak Bias 53 Bias 53 Mod 10 Skew 2 Gain X100 X100 X50 units Slew Normal Slow Normal 0 51 N A N A Noise 1 kHz 100 N A N A fT cmNHz Bandwidth 3 5 N A N A kHz Loop Locked yes yes yes N A Page 7 of 23 96252 2 2 Date 84 29 84 Time 81 21 88 A REPETI X 1 024 kHz Y 90 2701 85 dBUrms rtHz dB Mag dB div 1 35 256Hz AVG 305 182 4kHz Figure 7 5640325 noise measured at Tristan Test configuration SQUID Controller used iMC 303 S N 1093 Flux locked Loop used iFL 301 H S N 2064 SQUID sensor used S N SG40325 System Channel 3 Test Setup Gain x100 Slew Normal Heater Test Heat Time 15 sec Cool gt 99 sec Autotune Triangle Amplitude 1 4 Vpeak to peak Tune Parameters Bias 4096 Bias 4096 Mod 7296 Skew 496 Gain X100 X100 X50 uite Slew Normal Slow Normal 0 51 N A N A Noise 1 kHz 58 N A N A fT cmNHz Bandwidth 6 N A N A kHz Loop Locked yes yes yes N A Page 8 of 23 2 3 1 2 Unshielded Operation For planar gradiometers testing is also done in an unshielded environment Completely unshielded operation was achieved with all three channels simultaneously Channel 1 Channel 1 Channel 1 Loop Locked yes yes yes 2 3 2 Dewar Parameters The dewar const
24. ut of the dewar you are lowering the probe too fast Avoid freezing the o ring and pump out fitting When fully lowered secure the probe to the dewar with the proper hardware Remove the fill tube plug and install the funnel into the fill tube Again slowly pour LNe into the funnel until LN vents from the vent port Wait a moment and then add more LN until it again vents from the vent port Repeat this sequence until adding Page 13 of 23 LN causes immediate venting The dewar is now filled Remove funnel and replace it with the fill tube plug CAUTION O rings located on the probe will not be flexible if cold and may easily be cracked Spare o rings are provided CAUTION To avoid contamination of the vacuum space do not freeze the pump out valve on the top of the probe or the gasket on the top of the probe during transfer 4 NORMAL OPERATION 4 1 REFILLING THE DEWAR WITH LIQUID NITROGEN After the initial nitrogen transfer subsequent transfers will be required on a regular basis The boil off time recorded in Table 1 for the dewar will be reduced when a probe is installed and operating The dewar is designed to operate in the vertical position Boil off will increase when the dewar is tilted from vertical The boil off of the dewar with probe should be measured this will determine the minimum time between refills of the dewar The dewar should be refilled periodically and should not be allowed to warm unintentional
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