Lake Shore 475 User Manual

Manual is about: DSP Gaussmeter

Summary of 475

  • Page 1

    Lake shore model 475 gaussmeter user’s manual lake shore cryotronics, inc. 575 mccorkle blvd. Westerville, ohio 43082-8888 usa e-mail addresses: [email protected] [email protected] visit our website at: www.Lakeshore.Com fax: (614) 891-1392 telephone: (614) 891-2243 methods and apparatus discl...

  • Page 2

    Lake shore model 475 gaussmeter user’s manual limited warranty statement warranty period: three (3) years 1. Lake shore warrants that products manufactured by lake shore (the "product") will be free from defects in materials and workmanship for three years from the date of purchaser's physical recei...

  • Page 3

    Lake shore model 475 gaussmeter user’s manual 9. Lake shore disclaims any warranties of technological value or of non-infringement with respect to the product and lake shore shall have no duty to defend, indemnify, or hold harmless you from and against any or all damages or costs incurred by you ari...

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    Lake shore model 475 gaussmeter user’s manual trademark acknowledgment many manufacturers and sellers claim designations used to distinguish their products as trademarks. Where those designations appear in this manual and lake shore was aware of a trademark claim, they appear with initial capital le...

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    Lake shore model 475 gaussmeter user’s manual eu declaration of conformity this declaration of conformity is issued under the sole responsibility of the manufacturer. Manufacturer: lake shore cryotronics, inc. 575 mccorkle boulevard westerville, oh 43082 usa object of the declaration: model(s): 475 ...

  • Page 6

    Lake shore model 475 gaussmeter user’s manual copyright © 2003 – 2017 by lake shore cryotronics, inc. All rights reserved. No portion 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 other...

  • Page 7: Table Of Contents

    Lake shore model 475 gaussmeter user’s manual table of contents i table of contents chapter/section title page 1 introduction ....................................................................................................................... 1-1 1.0 general .........................................

  • Page 8: Table Of Contents

    Lake shore model 475 gaussmeter user’s manual ii table of contents table of contents chapter/paragraph title page 4 operation .............................................................................................................................. 4-1 4.0 general ..................................

  • Page 9: Table Of Contents

    Lake shore model 475 gaussmeter user’s manual table of contents iii table of contents chapter/paragraph title page 5 advanced operation........................................................................................................ 5-1 5.0 general ...............................................

  • Page 10: Table Of Contents

    Lake shore model 475 gaussmeter user’s manual iv table of contents table of contents chapter/paragraph title page 7 probes and accessories ................................................................................................ 7-1 7.0 general ...................................................

  • Page 11: Chapter 1

    Lake shore model 475 gaussmeter user’s manual introduction 1-1 chapter 1 introduction 1.0 general this chapter provides an introduction to the model 475 dsp gaussmeter. The model 475 was designed and manufactured in the united states of america by lake shore cryotronics, inc. The model 475 includes ...

  • Page 12

    Lake shore model 475 gaussmeter user’s manual 1-2 introduction dc measurement mode: static or slowly changing fields are measured in dc mode where the accuracy, resolution, and stability of the model 475 are most evident. The gaussmeter takes advantage of the internal auto zero function and probe li...

  • Page 13

    Lake shore model 475 gaussmeter user’s manual introduction 1-3 1.1.2 measurement features the model 475 offers a variety of features, implemented in the instrument firmware, to enhance usability and convenience of the gaussmeter. Auto range: in addition to manual range selection, the instrument will...

  • Page 14

    Lake shore model 475 gaussmeter user’s manual 1-4 introduction probe availability: listed in chapter 7 with specifications are some of the commonly used probes for the model 475 gaussmeter. This is by no means the limit of what is offered. All probe physical configurations previously supplied with t...

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    Lake shore model 475 gaussmeter user’s manual introduction 1-5 1.2 specifications full specifications about the model 475 gaussmeter are provided on our website. Please see: http://www.Lakeshore.Com/products/gaussmeters/model-475-dsp-gaussmeter/pages/specifications.Aspx . 1.3 safety summary observe ...

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    Lake shore model 475 gaussmeter user’s manual 1-6 introduction 1.4 safety symbols.

  • Page 17: Chapter 2

    Lake shore model 475 gaussmeter user’s manual background 2-1 chapter 2 background 2.0 general this chapter provides background information related to the model 475 gaussmeter. It is intended to give the user insight into the benefits and limitations of the instrument and help apply the features of t...

  • Page 18

    Lake shore model 475 gaussmeter user’s manual 2-2 background the rate at which an analog signal must be sampled depends on the frequency content of the signal. A signal is said to be properly sampled if the original signal can be exactly reconstructed from the digital information. It turns out that ...

  • Page 19

    Lake shore model 475 gaussmeter user’s manual background 2-3 2.1.5 dc measurement the dc mode should be used to measure static or slowly changing fields. When in dc mode, the instrument uses a 100 ma, 5khz, square wave excitation current. The voltage that is generated by the hall device is read by t...

  • Page 20

    Lake shore model 475 gaussmeter user’s manual 2-4 background in wide-band ac measurement, the instrument uses a 100 ma, dc excitation current. This type of excitation provides the greatest frequency range for rms measurements, up to 50 khz. The voltage that is generated by the hall device is read by...

  • Page 21

    Lake shore model 475 gaussmeter user’s manual background 2-5 2.2 flux density overview 2.2.1 what is flux density? A magnetic field can be envisioned as consisting of flux lines ( φ ) . A unit of flux is called a line. In the cgs system, one line of flux equals one maxwell (mx). In the si system, th...

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    Lake shore model 475 gaussmeter user’s manual 2-6 background the hall voltage can be given by the expression: v h = γ b b sin θ where: v h = hall voltage (mv) γ b = magnetic sensitivity (mv/kg) (at a fixed current) b = magnetic field flux density (kilogauss) θ = angle between magnetic flux vector an...

  • Page 23

    Lake shore model 475 gaussmeter user’s manual background 2-7 2.3.3 orientation hall generators come in two main configurations, axial and transverse. Transverse devices are generally thin and rectangular in shape. They are applied successfully in magnetic circuit gaps, surface measurements and gener...

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    Lake shore model 475 gaussmeter user’s manual 2-8 background 2.4.1.1 proportional (p) the value of the proportional term is multiplied by the error (e) which is defined as the difference between the setpoint and feedback field measurement, to generate the proportional contribution to the output: out...

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    Lake shore model 475 gaussmeter user’s manual background 2-9 figure 2-8. Examples of pi control.

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    Lake shore model 475 gaussmeter user’s manual 2-10 background 2.4.2 tuning a closed loop pi controller there has been a lot written about tuning closed loop control systems and specifically pi control loops. This section does not attempt to compete with control theory experts. It describes a few bas...

  • Page 27: Chapter 3

    Lake shore model 475 gaussmeter user’s manual installation 3-1 chapter 3 installation 3.0 general this chapter provides general installation instructions for the model 475 gaussmeter. Please read this entire chapter before installing the instrument and powering it on to ensure the best possible perf...

  • Page 28

    Lake shore model 475 gaussmeter user’s manual 3-2 installation 3.2 rear panel definition this paragraph defines the rear panel of the model 475. See figure 3-1. Readers are referred to paragraphs that contain installation instructions and connector pin-outs for each feature. A summary of connector p...

  • Page 29

    Lake shore model 475 gaussmeter user’s manual installation 3-3 3.3 line input assembly this section describes how to properly connect the model 475 to line power. Please follow these instructions carefully to ensure proper operation of the instrument and the safety of operators. 475_power.Bmp figure...

  • Page 30

    Lake shore model 475 gaussmeter user’s manual 3-4 installation 3.4 probe input connection warning: probes used with the gaussmeter have conductive parts. Never probe near exposed live voltage. Personal injury and damage to the instrument may result. The lake shore probe plugs into the 15 pin d-sub c...

  • Page 31

    Lake shore model 475 gaussmeter user’s manual installation 3-5 figure 3-3. Maximum flexible probe bend radius 3.5.2 probe operation in the dc mode of operation, the orientation of the probe affects the polarity reading of the gaussmeter. On a transverse probe, the lake shore name printed on the hand...

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    Lake shore model 475 gaussmeter user’s manual 3-6 installation 3.5.3 probe accuracy considerations the user must consider all the possible contributors to the accuracy of the reading. Both the probe and gaussmeter have accuracy specifications that may impact the actual reading. The probe should be z...

  • Page 33

    Lake shore model 475 gaussmeter user’s manual installation 3-7 3.6 auxiliary i/o connection the auxiliary connector is a 25 pin d-sub plug. This provides access to the analog outputs, hardware triggers, and relays. The pins are defined in the following table. Auxiliary_io.Bmp figure 3-6. Auxiliary i...

  • Page 34

    Lake shore model 475 gaussmeter user’s manual 3-8 installation 3.7 rack mounting the model 475 can be installed into a 19-inch rack mount cabinet using the optional lake shore model rm½ rack- mount kit, or the model rm2 dual rack-mount shelf. The rack-mount kit contains mounting ears, panel, handles...

  • Page 35

    Lake shore model 475 gaussmeter user’s manual installation 3-9 figure 3-8. Model rm2 dual rack-mount shelf (p/n 4026).

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  • Page 37: Chapter 4

    Lake shore model 475 gaussmeter user’s manual operation 4-1 chapter 4 operation 4.0 general this chapter provides instructions for the general operating features of the model 475 gaussmeter. Advanced operation including probe management and field control are in chapter 5. Computer interface instruct...

  • Page 38

    Lake shore model 475 gaussmeter user’s manual 4-2 operation 4.2 display definition in normal operation, the two row by twenty character vacuum fluorescent display provides readings defined by the selected measurement features on the top row, and special information or readings on the bottom row. The...

  • Page 39

    Lake shore model 475 gaussmeter user’s manual operation 4-3 display annunciators ° indicates that the relative measurement mode is on. Sp indicates the relative setpoint value. Csp indicates the field control setpoint value. Led annunciators relative indicates that the relative measurement mode is o...

  • Page 40

    Lake shore model 475 gaussmeter user’s manual 4-4 operation 4.3.2 general keypad operation the model 475 uses four basic keypad operations, direct operation, press and hold , setting selection and data entry, for the majority of operator interface. A few specialized keypad operations, such as user c...

  • Page 41

    Lake shore model 475 gaussmeter user’s manual operation 4-5 4.4.2 display brightness to change the brightness, press and hold the display key for approximately 4 seconds. The display configuration screen appears as a prompt for display brightness. Operating continuously at 100% brightness will short...

  • Page 42

    Lake shore model 475 gaussmeter user’s manual 4-6 dc operation operation 4.6 dc measurement mode to measure static or slowly changing fields, press the dc key on the front panel. In dc measurement mode, the keypad and functionality of the model 475 is optimized to provide the best interaction for dc...

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    Lake shore model 475 gaussmeter user’s manual operation dc operation 4-7 selecting the range this way will disable the auto range function. To enable the auto range function, press autorange . The autorange setup screen appears as a prompt for turning the auto range function on or off. Sel ec t wi t...

  • Page 44

    Lake shore model 475 gaussmeter user’s manual 4-8 dc operation operation to zero the probe in the zero gauss chamber, first allow the temperature of the probe and chamber to equalize. (a large temperature discrepancy affects the quality of the calibration.) carefully place the probe tip into the cha...

  • Page 45

    Lake shore model 475 gaussmeter user’s manual operation dc operation 4-9 example: if the present maximum reading is +20 kg and the instrument measures –35 kg, the –35 kg becomes the new maximum reading. If the minimum reading is –3.0 kg and the instrument measures –1.5 kg, the –1.5 kg becomes the ne...

  • Page 46

    Lake shore model 475 gaussmeter user’s manual 4-10 dc operation operation 4.6.4.2 max/min display setting typically, the maximum reading (max) is displayed on the top line when the max hold feature is on. Sometimes it may be beneficial to display the minimum reading (min) on the top line instead of ...

  • Page 47

    Lake shore model 475 gaussmeter user’s manual operation dc operation 4-11 if the relative mode is configured to use the present field as the setpoint, the off to on transition will capture the field reading to use as the setpoint. If a user defined setpoint is selected, the following screen appears ...

  • Page 48

    Lake shore model 475 gaussmeter user’s manual 4-12 rms operation operation 4.7 rms measurement mode to measure periodic, ac fields, press the rms key on the front panel. In rms measurement mode, the keypad and functionality of the model 475 is optimized to provide the best interaction for rms measur...

  • Page 49

    Lake shore model 475 gaussmeter user’s manual operation rms operation 4-13 for manual ranging, press the select range key. The range setup screen appears as a prompt for changing the range. Sel ec t wi t h ° ® ra n g e + 3 . 5 0 0 0 k g use the s or t key to select from the available ranges. Press e...

  • Page 50

    Lake shore model 475 gaussmeter user’s manual 4-14 rms operation operation figure 4-3. Wide band and narrow band filter 4.7.2.1 wide band filters dc current excitation provides the greatest frequency range for rms measurement. This frequency range is then divided into smaller sections by using the b...

  • Page 51

    Lake shore model 475 gaussmeter user’s manual operation rms operation 4-15 4.7.2.2 narrow band filters ac current excitation, provides the benefit of noise cancellation characteristics of the product detector, but limits the maximum frequency to approximately 1 khz. This frequency range is then divi...

  • Page 52

    Lake shore model 475 gaussmeter user’s manual 4-16 rms operation operation figure 4-4. Lowpass filter lowpass setting f c (hz) stop f stop (hz) 20 40 60 80 140 160 if filter lowpass is selected the next screen appears as a prompt for selecting the corner frequency of the lowpass filter. Sel ec t wi ...

  • Page 53

    Lake shore model 475 gaussmeter user’s manual operation rms operation 4-17 4.7.3 rms operation frequency measurement with certain limitations, the model 475 gaussmeter is capable of measuring and displaying the frequency of an ac magnetic field. The frequency is calculated using a zero-crossing coun...

  • Page 54

    Lake shore model 475 gaussmeter user’s manual 4-18 rms operation operation 4.7.5 rms operation max hold the max hold function captures the largest (maximum) or smallest (minimum) rms field readings since the last reset press. To turn the max hold feature on, press the max hold key. The following scr...

  • Page 55

    Lake shore model 475 gaussmeter user’s manual operation rms operation 4-19 to turn the relative function on, press the relative key. The following screen will appear for approximately 3 seconds and the relative led will light. Rel at i v e on the relative function also interacts with other features....

  • Page 56

    Lake shore model 475 gaussmeter user’s manual 4-20 peak operation operation 4.8 peak measurement mode to measure pulsed or periodic fields, press the peak key on the front panel. In peak measurement mode, the keypad and functionality of the model 475 is optimized to provide the best interaction for ...

  • Page 57

    Lake shore model 475 gaussmeter user’s manual operation peak operation 4-21 4.8.2 peak operation periodic/pulse setup the peak measurement mode can be configured to measure pulsed fields or the maximum amplitude of periodic fields. In periodic mode, the instrument follows the peak amplitude of the p...

  • Page 58

    Lake shore model 475 gaussmeter user’s manual 4-22 peak operation operation 4.8.6 peak operation relative the relative function lets the user see small variations in larger fields. When the relative function is on, the relative readings will appear on the top line of the display including the small ...

  • Page 59

    Lake shore model 475 gaussmeter user’s manual operation 4-23 4.9 temperature measurement the model 475 is capable of measuring the temperature of the probe, if the probe is equipped with a temperature sensor and a temperature compensation table. The probe temperature can be displayed as kelvin or in...

  • Page 60

    Lake shore model 475 gaussmeter user’s manual 4-24 operation the alarm may be configured to use the magnitude of the field reading only (ignoring the sign), or to include the sign and treat the readings algebraically. To configure the alarm for magnitude or algebraic mode, press and hold the alarm k...

  • Page 61

    Lake shore model 475 gaussmeter user’s manual operation 4-25 the model 475 has an audible alarm annunciator or beeper. The beeper will sound when the instrument is in an active alarm state. If the sound of the beeper is not appropriate for your application, it can be turned on or off by the user..

  • Page 62

    Lake shore model 475 gaussmeter user’s manual 4-26 operation to configure the beeper, continue from the alarm inside/outside setup screen or press and hold alarm and then press enter until the following screen appears as a prompt for configuring the beeper. Sel ec t wi t h ° ® al a r m au d i b l e ...

  • Page 63

    Lake shore model 475 gaussmeter user’s manual operation 4-27 the next relay setup screen appears as a prompt for operating mode. Sel ec t f or rel 1 ° ® re l a y 1 on use the s or t key to select the relay mode for manual operation (off, on) or to follow the alarm operation. Press enter to accept th...

  • Page 64

    Lake shore model 475 gaussmeter user’s manual 4-28 operation 0 v +1.5 v +2.5 v +3.5 v –3.5 v –2.5 v –1.5 v 0 kg +1.5 kg +2.5 kg +3.5 kg –3.5 kg –2.5 kg –1.5 kg display reading output voltage if the user defined mode is selected, the next analog setup screen appears as a prompt for the low setpoint v...

  • Page 65

    Lake shore model 475 gaussmeter user’s manual operation 4-29 if the manual mode is selected, the manual entry screen appears following the analog mode setting screen. The setting range is from 0% to 100% (if unipolar) or from -100% to 100% (if bipolar), with a setting resolution of 0.001%. A value o...

  • Page 66

    Lake shore model 475 gaussmeter user’s manual 4-30 operation 4.13 locking the keypad the keypad lock feature prevents accidental changes to parameter values. When the keypad is locked all parameter values may be viewed but none may be changed from the front panel. A 3-digit code must be used to lock...

  • Page 67

    Lake shore model 475 gaussmeter user’s manual operation 4-31 the next screen appears as a prompt for returning the instrument parameters to default values. Default parameter values are listed in table 4-1. Se l e c t wi t h ° ® de f a u l t va l u e s no use the s or t keys to select yes for default...

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  • Page 69: Chapter 5

    Lake shore model 475 gaussmeter user’s manual advanced operation 5-1 chapter 5 advanced operation 5.0 general this chapter provides information on advanced operations for the model 475 dsp gaussmeter. 5.1 probe management the model 475 has several capabilities that allow the best possible measuremen...

  • Page 70

    Lake shore model 475 gaussmeter user’s manual 5-2 advanced operation some probes also feature temperature compensation. Turning temperature compensation off causes the model 475 to ignore this data. To configure the field compensation setting, press the probe key and wait until the probe serial numb...

  • Page 71

    Lake shore model 475 gaussmeter user’s manual advanced operation 5-3 visually verify that a valid hmpec cable is attached to the model 475. Press enter to copy the probe characteristics to the memory of the extension cable. Press escape to cancel the process and return to the normal display. If a va...

  • Page 72

    Lake shore model 475 gaussmeter user’s manual 5-4 advanced operation user programmable cable (continued) if a valid hmcbl cable is attached, the next mcbl program screen appears as a prompt for serial number entry. Ent er f or mcbl sn u m 1 0 0 0 0 0 0 0 0 0 use the number entry keys to enter the nu...

  • Page 73

    Lake shore model 475 gaussmeter user’s manual advanced operation 5-5 5.2.2 ohms measurement mode the model 475 may be configured to make a 4-lead resistive measurement. If the sensitivity of the probe is set to 0, the instrument will read in ohms. Instrument features are limited in this mode. The fo...

  • Page 74

    Lake shore model 475 gaussmeter user’s manual 5-6 advanced operation 5.3.3 p and i settings the proportional (p) and integral (i) parameter values must be properly selected to tune the control loop. Chapter 2 of this manual describes the principles of closed loop control including some tuning sugges...

  • Page 75

    Lake shore model 475 gaussmeter user’s manual advanced operation 5-7 5.3.5 control slope limit the model 475 analog output 3 (used during control) can be limited to protect the programmable power supply that it may be driving. Certain power supplies may have a maximum programmable voltage change, an...

  • Page 76

    Lake shore model 475 gaussmeter user’s manual 5-8 advanced operation 5.5 triggering a hardware, ttl level, trigger into the instrument can be used to initiate the data log sequence. A hardware, ttl level trigger out of the instrument indicates when the instrument completes a reading and can be used ...

  • Page 77: Chapter 6

    Lake shore model 475 gaussmeter user’s manual remote operation 6-1 chapter 6 computer interface operation 6.0 general this chapter provides operational instructions for the computer interface for the lake shore model 475 gaussmeter. Either of the two computer interfaces provided with the model 475 p...

  • Page 78

    Lake shore model 475 gaussmeter user’s manual 6-2 remote operation 6.1.1 changing ieee-488 interface parameters two interface parameters. Address and terminators, must be set from the front panel before communication with the instrument can be established. Other interface parameters can be set via t...

  • Page 79

    Lake shore model 475 gaussmeter user’s manual remote operation 6-3 a multiline command asserts a group of signal lines. All devices equipped to implement such commands do so simultaneously upon command transmission. These commands transmit with the attention (atn) line asserted low. The model 475 re...

  • Page 80

    Lake shore model 475 gaussmeter user’s manual 6-4 remote operation 6.1.3.5 high speed binary output configuration the model 475 is capable of sending field readings over the ieee interface at a rate of 100 readings per second. For this to be possible, the data is sent in the ieee-754 floating point ...

  • Page 81

    Lake shore model 475 gaussmeter user’s manual remote operation 6-5 6.1.4 status system 6.1.4.1 overview the model 475 implements a status system compliant to the ieee 488.2 – 1992 standard. The status system provides a method of recording and reporting instrument information and is typically used to...

  • Page 82

    Lake shore model 475 gaussmeter user’s manual 6-6 remote operation figure 6-2. Model 475 status system.

  • Page 83

    Lake shore model 475 gaussmeter user’s manual remote operation 6-7 6.1.4.1.5 reading registers any register in the status system may be read using the appropriate query command. Some registers clear when read, others do not. Refer to paragraph 6.1.4.1.7. The response to a query will be a decimal val...

  • Page 84

    Lake shore model 475 gaussmeter user’s manual 6-8 remote operation 6.1.4.2 status register sets as shown in figure 6-2, there are two register sets in the status system of the model 475: standard event status register and operation event register. 6.1.4.2.1 standard event status register set the sta...

  • Page 85

    Lake shore model 475 gaussmeter user’s manual remote operation 6-9 figure 6-4. Operation event register 6.1.4.3 status byte and service request (srq) as shown in figure 6-2, the status byte register receives the summary bits from the two status register sets and the message available summary bit fro...

  • Page 86

    Lake shore model 475 gaussmeter user’s manual 6-10 remote operation 6.1.4.3.2 service request enable register the service request enable register is programmed by the user and determines which summary bits of the status byte may set bit 6 (rqs/mss) to generate a service request. Enable bits are logi...

  • Page 87

    Lake shore model 475 gaussmeter user’s manual remote operation 6-11 table 6-3. Programming example to generate an srq command or operation description *esr? Read and clear the standard event status register. *ese 32 enable the command error (cme) bit in the standard event status register *sre 32 ena...

  • Page 88

    Lake shore model 475 gaussmeter user’s manual 6-12 remote operation 6.1.5 ieee interface example program a visual basic program is included to illustrate the ieee-488 communication functions of the instrument. Refer to paragraph 6.1.5.1 for instructions on how to setup the program. The visual basic ...

  • Page 89

    Lake shore model 475 gaussmeter user’s manual remote operation 6-13 figure 6-6. Gpib0 setting configuration figure 6-7. Dev 12 device template configuration.

  • Page 90

    Lake shore model 475 gaussmeter user’s manual 6-14 remote operation 6.1.5.2 visual basic ieee-488 interface program setup this ieee-488 interface program works with visual basic 6.0 (vb6) on an ibm pc (or compatible) with a pentium- class processor. A pentium 90 or higher is recommended, running win...

  • Page 91

    Lake shore model 475 gaussmeter user’s manual remote operation 6-15 table 6-4. Ieee-488 interface program control properties current name property new value label1 name caption lblexitprogram type “exit” to end program. Label2 name caption lblcommand command label3 name caption lblresponse response ...

  • Page 92

    Lake shore model 475 gaussmeter user’s manual 6-16 remote operation table 6-5. Visual basic ieee-488 interface program public gsend as boolean 'global used for send button state private sub cmdsend_click() 'routine to handle send button press gsend = true 'set flag to true end sub private sub form_l...

  • Page 93

    Lake shore model 475 gaussmeter user’s manual remote operation 6-17 6.1.5.3 program operation once either example program is running, try the following commands and observe the response of the instrument. Input from the user is shown in bold and terminators are added by the program. The word [term] ...

  • Page 94

    Lake shore model 475 gaussmeter user’s manual 6-18 remote operation 6.2 serial interface overview the serial interface used in the model 475 is commonly referred to as an rs-232c interface. Rs-232c is a standard of the electronics industries association (eia) that describes one of the most common in...

  • Page 95

    Lake shore model 475 gaussmeter user’s manual remote operation 6-19 6.2.3 hardware support the model 475 interface hardware supports the following features. Asynchronous timing is used for the individual bit data within a character. This timing requires start and stop bits as part of each character ...

  • Page 96

    Lake shore model 475 gaussmeter user’s manual 6-20 remote operation message strings (continued) a query string is issued by the computer and instructs the instrument to send a response. The query format is: >. Query mnemonics are often the same as commands with the addition of a question mark. Param...

  • Page 97

    Lake shore model 475 gaussmeter user’s manual remote operation 6-21 6.2.7.1 visual basic serial interface program setup the serial interface program works with visual basic 6.0 (vb6) on an ibm pc (or compatible) with a pentium-class processor. A pentium 90 or higher is recommended, running windows 9...

  • Page 98

    Lake shore model 475 gaussmeter user’s manual 6-22 remote operation table 6-7. Serial interface program control properties current name property new value label1 name caption lblexitprogram type “exit” to end program. Label2 name caption lblcommand command label3 name caption lblresponse response te...

  • Page 99

    Lake shore model 475 gaussmeter user’s manual remote operation 6-23 table 6-8. Visual basic serial interface program public gsend as boolean 'global used for send button state private sub cmdsend_click() 'routine to handle send button press gsend = true 'set flag to true end sub private sub form_loa...

  • Page 100

    Lake shore model 475 gaussmeter user’s manual 6-24 remote operation 6.2.7.2 program operation once either example program is running, try the following commands and observe the response of the instrument. Input from the user is shown in bold and terminators are added by the program. The word [term] ...

  • Page 101

    Lake shore model 475 gaussmeter user’s manual remote operation 6-25 6.3 command summary this paragraph provides a listing of the ieee-488 and serial interface commands. A summary of all the commands is provided in table 6-9. All the commands are detailed in paragraph 6.3.1, presented in alphabetical...

  • Page 102

    Lake shore model 475 gaussmeter user’s manual 6-26 remote operation table 6-9. Command summary command function page q cls clear interface cmd ..............................................6-27 q ese standard event status enable register cmd .........6-27 q ese? Standard event status enable register...

  • Page 103

    Lake shore model 475 gaussmeter user’s manual remote operation 6-27 6.3.1 interface commands (alphabetical listing) *cls clear interface command input: * cls [term] remarks: clears the bits in the standard event status register and operation event register and terminates all pending operations. Clea...

  • Page 104

    Lake shore model 475 gaussmeter user’s manual 6-28 remote operation *opc? Operation complete query input: * opc? [term] returned: 1[term] remarks: has no interaction with bit 0 (opc) of the standard event status register. If sent at the end of a command sequence, the bus will be held until the instr...

  • Page 105

    Lake shore model 475 gaussmeter user’s manual remote operation 6-29 alarm alarm parameter command input: alarm , , , , , [term] format: n,n, ± nnn.Nnne ± nn, ± nnn.Nnne ± nn,n,n specifies alarm checking on or off: 0 = off, 1 = on. Specifies checking magnitude(absolute value used) or algebraically(in...

  • Page 106

    Lake shore model 475 gaussmeter user’s manual 6-30 remote operation analog? Analog output 3 parameter query input: analog? [term] returned: , , , , , [term] format: n,n, ± nnn.Nnne ± nn, ± nnn.Nnne ± nn, ± nnn.Nnne ± nn (refer to command for definition) aout? Analog output 3 data query input: aout? ...

  • Page 107

    Lake shore model 475 gaussmeter user’s manual remote operation 6-31 brigt? Display brightness query input: brigt? [term] returned: [term] format: n (refer to command for description) cmode field control mode command input: cmode [term] format: n specifies the control mode. Valid entries: 0 = off, 1 ...

  • Page 108

    Lake shore model 475 gaussmeter user’s manual 6-32 remote operation dflt factory defaults command input: dflt 99 [term] remarks: sets all configuration values to factory defaults and resets the instrument. The "99" is included to prevent accidentally setting the unit to defaults. Display display con...

  • Page 109

    Lake shore model 475 gaussmeter user’s manual remote operation 6-33 dlogset datalog rate command input: dlogset [term] format: n configures the datalog readings per second: 1 = 1 reading per second 2 = 10 readings per second 3 = 30 readings per second 4 = 100 readings per second 5 = 200 readings per...

  • Page 110

    Lake shore model 475 gaussmeter user’s manual 6-34 remote operation ieee? Ieee-488 interface parameter query input: ieee? [term] returned: , , [term] format: n,n,nn (refer to command for description) keyst? Keypad status query input: keyst?[term] returned: [term] format: n remarks: returns a number ...

  • Page 111

    Lake shore model 475 gaussmeter user’s manual remote operation 6-35 mode remote interface mode command input: mode [term] format: n 0 = local, 1 = remote, 2 = remote with local lockout. Example: mode 2[term] – places the model 475 into remote mode with local lockout. Mode? Remote interface mode quer...

  • Page 112

    Lake shore model 475 gaussmeter user’s manual 6-36 remote operation prbfcomp probe field compensation command input: prbfcomp [term] format: n specifies probe field compensation off or on. Valid entries: 0 = off, 1 = on. Example: prbfcomp 1[term] – field measurement uses the probe field compensation...

  • Page 113

    Lake shore model 475 gaussmeter user’s manual remote operation 6-37 range? Field range query input: range? [term] returned: [term] format: n (refer to command for description) rdgfast? Binary field reading query input: rdgfast?[term] format: nnnnn specifies number of readings to retrieve: 1 – 99999....

  • Page 114

    Lake shore model 475 gaussmeter user’s manual 6-38 remote operation rdgmnmx? Minimum and maximum reading query input: rdgmnmx? [term] returned: ,[term] format: ± nnn.Nnne ± nn, ± nnn.Nnne ± nn remarks: returns the most recent minimum and maximum field readings. Rdgohm? Resistance reading query input...

  • Page 115

    Lake shore model 475 gaussmeter user’s manual remote operation 6-39 relay relay parameter command input: relay , , [term] format: n,n,nn,n specifies which relay to configure: 1 = relay 1, 2 = relay 2. Specifies relay mode: 0 = off, 1 = on, 2 = alarms. Specifies the alarm type that activates the rela...

  • Page 116

    Lake shore model 475 gaussmeter user’s manual 6-40 remote operation tunit probe temperature units command input: tunit [term] format: n 1 = celsius, 2 = kelvin example: tunit 1[term] – configures the model 475 to report probe temperature in °c. Tunit? Probe temperature units query input: tunit? [ter...

  • Page 117: Chapter 7

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-1 chapter 7 probes and accessories 7.0 general this chapter provides information on the accessories and probes available for the model 475 dsp gaussmeter. 7.1 models the list of model 475 model numbers is provided as follows. Mod...

  • Page 118

    Lake shore model 475 gaussmeter user’s manual 7-2 probes and accessories 7.3 lake shore standard probes there are several types of lake shore model 475 probes available: axial, gamma, tangential, and transverse — generally named for the hall sensor orientation. Because the model 475 covers such a wi...

  • Page 119

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-3 tangential: tangential probes are special transverse versions designed to measure fields parallel to and near a surface. The active area is very close to the stem tip. These probes are intended for this special application and ...

  • Page 120

    Lake shore model 475 gaussmeter user’s manual 7-4 probes and accessories 7.3.2 radiation effects on gaussmeter probes the hst and hse probes use a highly doped indium arsenide active material. The hst material is the more highly doped of the two and therefore will be less affected by radiation. Some...

  • Page 121

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-5 7.3.4 probe specifications full specifications about the model 475 gaussmeter are provided on our website. Please see: http://www.Lakeshore.Com/products/gaussmeters/model-475-dsp-gaussmeter/pages/specifications.Aspx . 7.4 probe...

  • Page 122

    Lake shore model 475 gaussmeter user’s manual 7-6 probes and accessories mra-xxx mrt-xxx reference magnets . High-quality reference magnets are available in transverse (flat) and axial (round) configurations. Refer to paragraph 7.7 and see figure 7-16. Mra-312-100 axial reference magnet: 0.312 inch ...

  • Page 123

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-7 7.5 hall generator lake shore sells a series of bare hall generators for applications that are unsuitable for standard probe configurations. This section describes the handling, wiring and specifications of the bare hall genera...

  • Page 124

    Lake shore model 475 gaussmeter user’s manual 7-8 probes and accessories 7.5.4 attachment to a user programmable cable the model hmcbl-xx has a 15 pin d-sub connector on one end for direct attachment to the probe input connection on the back panel of the model 475 gaussmeter. Four tinned wires are p...

  • Page 125

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-9 7.6 helmholtz coil low field standards lake shore offers three helmholtz coils: 2.5-, 6-, and 12-inch diameter. Check the lake shore website for any recent additions to this line. These coils are accurately calibrated using fie...

  • Page 126

    Lake shore model 475 gaussmeter user’s manual 7-10 probes and accessories helmholtz_6.Bmp figure 7-14. Model mh-6 helmholtz coil helmholtz_12.Bmp figure 7-15. Model mh-12 helmholtz coil.

  • Page 127

    Lake shore model 475 gaussmeter user’s manual probes and accessories 7-11 7.7 reference magnets magnetic reference standards containing highly stable permanent magnets have been in use for many years. The highest quality units are usually shielded from external magnetic effects and use alnico v or v...

  • Page 128

    Lake shore model 475 gaussmeter user’s manual 7-12 probes and accessories 7.8 zero gauss chamber note: use care to ensure the zero gauss chamber does not become magnetized. Using a magnetized chamber to zero a probe can lead to erroneous field readings. It is a good practice to periodically degauss ...

  • Page 129: Chapter 8

    Lake shore model 475 gaussmeter user’s manual service 8-1 chapter 8 service 8.0 general this chapter provides basic service information for the model 475 gaussmeter. Customer service of the product is limited to the information presented in this chapter. Factory trained service personnel should be c...

  • Page 130

    Lake shore model 475 gaussmeter user’s manual 8-2 service 8.3 fuse drawer the fuse drawer supplied with the model 475 holds the instrument line fuses and line voltage selection module. The drawer holds two 5 × 20 mm time delay fuses. It requires two good fuses of the same rating to operate safely. F...

  • Page 131

    Lake shore model 475 gaussmeter user’s manual service 8-3 fuse replacement (continued) note: test fuse with an ohmmeter. Do not rely on visual inspection of fuse. 1. Locate line input assembly on the instrument rear panel. See figure 8-2. 2. Turn power switch off ( o ). 3. Remove instrument power co...

  • Page 132

    Lake shore model 475 gaussmeter user’s manual 8-4 service 8.7 electrostatic discharge electrostatic discharge (esd) may damage electronic parts, assemblies, and equipment. Esd is a transfer of electrostatic charge between bodies at different electrostatic potentials caused by direct contact or induc...

  • Page 133

    Lake shore model 475 gaussmeter user’s manual service 8-5 8.8 enclosure top removal and replacement warning: to avoid potentially lethal shocks, turn off controller and disconnect it from ac power line before performing this procedure. Only qualified personnel should perform this procedure. Removal ...

  • Page 134

    Lake shore model 475 gaussmeter user’s manual 8-6 service pcb layout.Bmp figure 8-3. Location of important internal components.

  • Page 135

    Lake shore model 475 gaussmeter user’s manual service 8-7 firmware replacement (continued) caution: the ics are electrostatic discharge sensitive (esds) devices. Wear shock-proof wrist straps (resistor limited to electrostatic discharge (esd) into the device. 3. Use ic puller to remove existing ic f...

  • Page 136

    Lake shore model 475 gaussmeter user’s manual 8-8 service probe_input.Bmp pin description pin description 1 2 3 4 5 6 7 8 v input + no connection v temp + i temp + i temp – v temp – no connection i hall + 9 10 11 12 13 14 15 v input – no connection eeprom gnd eeprom vcc eeprom clk eeprom data i hall...

  • Page 137

    Lake shore model 475 gaussmeter user’s manual service 8-9 8.10.1 serial interface cable wiring the following are suggested cable wiring diagrams for connecting the model 475 serial interface to various customer personal computers (pcs). Model 475 to pc serial interface – pc with de-9p model 475 de-9...

  • Page 138

    Lake shore model 475 gaussmeter user’s manual 8-10 service 8.10.2 ieee-488 interface connector connect to the ieee-488 interface connector on the model 475 rear with cables specified in the ieee-488-1978 standard document. The cable has 24 conductors with an outer shield. The connectors are 24-way a...

  • Page 139

    Lake shore model 475 gaussmeter user’s manual service 8-11 8.11 calibration procedure 8.11.1 equipment required for calibration pc and interface • pc with software loaded which provides serial command line communication. (example program in paragraph 6.2.7 is ideal for this purpose.) • de-9 to de-9 ...

  • Page 140

    Lake shore model 475 gaussmeter user’s manual 8-12 service 16. Configure the 475 excitation current to -100 ma (hallcs 1;csmode 3). 17. Read the current using the dvm. Store as avgnegcurrent. 18. Connect the dvm voltage input across the 3 Ω resistor. 19. Read the voltage using the dvm. Store as avgn...

  • Page 141

    Lake shore model 475 gaussmeter user’s manual service 8-13 17. Configure the 475 range to the 3.5 Ω range (range 4). 18. Read the resistor using the 475 (rdgohm?). Store as actualresistance. 19. Calculate the gain calibration factor (gcf) = expectedresistance /actualresistance. Test this factor to b...

  • Page 142

    Lake shore model 475 gaussmeter user’s manual 8-14 service 8.11.3 temperature measurement calibration this section performs the calibration on the temperature measurement. The model 475 has three excitation currents for temperature measurement. Each one of these is used to measure the appropriate 0....

  • Page 143

    Lake shore model 475 gaussmeter user’s manual service 8-15 13. Configure analog output 2 to manual mode, -50% (mout 1,-50). 14. Read the voltage using the dvm. Verify the reading to be –2.5 vdc, ±1 mv. Record the reading. 15. Configure analog output 2 to manual mode, +50% (mout 1,50). 16. Read the v...

  • Page 144

    Lake shore model 475 gaussmeter user’s manual 8-16 service 8.11.5 calibration specific interface commands calg gain calibration constant command input: calg , , [term] format: n,n,±nnnnnnn specifies the item to calibrate. Valid entries are: 1 = 100 ma hall current source 2 = 10 ma hall current sourc...

  • Page 145

    Lake shore model 475 gaussmeter user’s manual service 8-17 calz zero offset calibration constant command input: calz , , [term] format: n,n,±nnnnnnn specifies the item to calibrate. Valid entries are: 1 = 100 ma hall current source (not used) 2 = 10 ma hall current source (not used) 3 = 1 ma hall cu...

  • Page 146

    Lake shore model 475 gaussmeter user’s manual 8-18 service hallcs hall current source range command input: hallcs [term] format: n specifies the hall current source range. Valid entries are: 1 = 100 ma range 2 = 10 ma range 3 = 1 ma range remarks: if a new probe is connected or the power is cycled o...

  • Page 147: Appendix A

    Lake shore model 475 gaussmeter user’s manual units for magnetic properties a-1 appendix a units for magnetic properties table a-1. Conversion from cgs to si units quantity symbol gaussian & cgs emu a conversion factor, c b si & rationalized mks c magnetic flux density, magnetic induction b gauss (g...

  • Page 148

    Lake shore model 475 gaussmeter user’s manual a-2 units for magnetic properties table a-2. Recommended si values for physical constants quantity symbol value (si units) permeability of vacuum µ 0 4 π × 10 –7 h m –1 speed of light in vacuum c 2.9979 × 10 8 m s –1 permitivity of vacuum ε 0 = (µ 0 c 2 ...