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Lakeshore 330 User Manual

Manual is about: Autotuning

Summary of 330

  • Page 1

    Rev. 1.3 p/n 119-009 15 november 2000 includes coverage for: model 330-1x – silicon diode model 330-2x – platinum resistor model 330-3x – gaalas diode model 330-4x – thermocouple model 330-5x – thermocouple lake shore cryotronics, inc. 575 mccorkle blvd. Westerville, ohio 43082-8888 usa e-mail addre...

  • Page 2

    Lake shore model 330 autotuning temperature controller user’s manual a limited warranty lake shore cryotronics, inc. (henceforth lake shore), the manufacturer, warrants this product to be free from defects in material or workmanship for a period of 12 months from the date of shipment. During the war...

  • Page 3: Declaration of Conformity

    Lake shore model 330 autotuning temperature controller user’s manual b declaration of conformity we: lake shore cryotronics, inc. 575 mccorkle blvd. Westerville, oh 43082-8888 usa hereby declare that the equipment specified conforms to the following directives and standards: application of council d...

  • Page 4

    Lake shore model 330 autotuning temperature controller user’s manual c electromagnetic compatibility (emc) for the model 330 temperature controller electromagnetic compatibility (emc) of electronic equipment is a growing concern worldwide. Emissions of and immunity to electromagnetic interference is...

  • Page 5

    Lake shore model 330 autotuning temperature controller user’s manual table of contents i table of contents chapter/paragraph title page 1 introduction ....................................................................................................................................1-1 1.0 general.....

  • Page 6

    Lake shore model 330 autotuning temperature controller user’s manual ii table of contents chapter/paragraph title page 3.2.7 softcal ............................................................................................................................. 3-5 3.2.7.1 softcal errors .................

  • Page 7

    Lake shore model 330 autotuning temperature controller user’s manual table of contents iii chapter/paragraph title page 4.3 ieee-488/serial interface command summary................................................................4-10 4.3.1 command list structure ........................................

  • Page 8

    Lake shore model 330 autotuning temperature controller user’s manual iv table of contents list of illustrations figure no. Title page 1-1 model 330 temperature controller front panel .............................................................................. 1-2 1-2 model 330 block diagram .........

  • Page 9: Chapter 1

    Lake shore model 330 autotuning temperature controller user’s manual introduction 1-1 chapter 1 introduction 1.0 general lake shore cryotronics, inc. Designed and manufactures the model 330 autotuning temperature controller in the united states of america. It is a microprocessor-based instrument wit...

  • Page 10

    Lake shore model 330 autotuning temperature controller user’s manual 1-2 introduction 1.1 model 330 temperature controller description the model 330 is a microcontroller-based autotuning temperature controller. There are four primary sensor input types: the model 330-1x for silicon diode temperature...

  • Page 11

    Lake shore model 330 autotuning temperature controller user’s manual introduction 1-3 table 1-1. Electronic information for various sensors and temperature ranges suffix 1 2 3 4 * sensor type silicon diode 100 Ω platinum rtd gaalas diode thermocouple sensor temperature coefficient negative positive ...

  • Page 12

    Lake shore model 330 autotuning temperature controller user’s manual 1-4 introduction table 1-2. Model 330 specifications thermometry: number of inputs: two sensor types: model 330-1x – silicon diode (sensors sold separately) model 330-2x – platinum rtd model 330-3x – gaalas diode model 330-4x – the...

  • Page 13

    Lake shore model 330 autotuning temperature controller user’s manual introduction 1-5 power supply analog digital display keypad micro- controller program prom rs-232c interface ram for curves d/a converter 15-bits ac line 3 2 1 ieee-488 interface current source a current source b a/d converter 16-b...

  • Page 14

    Lake shore model 330 autotuning temperature controller user’s manual 1-6 introduction 1.3 precision calibration options the lake shore precision calibration option converts calibrated sensor data into breakpoint pairs readable by the controller program. The precision calibration option is available ...

  • Page 15

    Lake shore model 330 autotuning temperature controller user’s manual introduction 1-7 1.5 handling liquid helium and liquid nitrogen liquid helium (lhe) and liquid nitrogen (ln 2 ) may be used in conjunction with the model 330. Although lhe and ln 2 are not explosive, there are certain safety consid...

  • Page 16

    Lake shore model 330 autotuning temperature controller user’s manual 1-8 introduction 1.6 safety summary observe these general safety precautions during all phases of instrument operation, service, and repair. Failure to comply with these precautions or with specific warnings elsewhere in this manua...

  • Page 17: Chapter 2

    Lake shore model 330 autotuning temperature controller user’s manual installation 2-1 chapter 2 installation 2.0 general this chapter covers general model 330 installation instructions: inspection and unpacking (paragraph 2.1), repackaging for shipment (paragraph 2.2), definition of rear panel conne...

  • Page 18

    Lake shore model 330 autotuning temperature controller user’s manual 2-2 installation 2.3 definition of rear panel connections the model 330 rear panel consists of the power and fuse assembly, ieee-488 interface connector, serial i/o connector, two sensor input connectors, and heater output connecti...

  • Page 19

    Lake shore model 330 autotuning temperature controller user’s manual installation 2-3 2.4 sensor input settings to configure sensor input type, set dip switches s1 and s2 on the main pcb inside the unit. To check dip switch settings, press input type. Input configurations are shown in table 2-1. To ...

  • Page 20

    Lake shore model 330 autotuning temperature controller user’s manual 2-4 installation 2.6 sensor installation this paragraph covers general sensor installation recommendations. See the lake shore product catalog or sensor guide for installation details and sensor specifications. Call lake shore for ...

  • Page 21

    Lake shore model 330 autotuning temperature controller user’s manual installation 2-5 2.6.1.2 heat sinking sensor leads excessive heat flow through connecting leads to any temperature sensor puts the active sensing element is at a different temperature than the sample to which the sensor mounts. Thi...

  • Page 22

    Lake shore model 330 autotuning temperature controller user’s manual 2-6 installation 2.6.1.4 measurement errors due to ac noise poorly shielded leads or improperly grounded measurement systems can introduce ac noise into sensor leads. For diode sensors, ac noise appears as a shift in the dc voltage...

  • Page 23

    Lake shore model 330 autotuning temperature controller user’s manual installation 2-7 type e (chromel™-constantan) type e is a thermocouple pair consisting of a ni-cr alloy (chromel™) as the positive thermoelement and a cu-ni alloy (constantan) as the negative thermoelement. It has the highest sensi...

  • Page 24

    Lake shore model 330 autotuning temperature controller user’s manual 2-8 installation table 2-3. Sensor curves sensor curves are defined as follows: d and e1 curve: older lake shore dt-500 series diode sensors can still use the model 330 when set to d-curve (domestic) or e1- curve (export). Curve 10...

  • Page 25

    Lake shore model 330 autotuning temperature controller user’s manual installation 2-9 2.9 heater setup model 330 heater output is on the rear panel as a dual banana jack. A mating connector is supplied. Current is driven from the heater output hi connection to the lo connection. Connect a resistive ...

  • Page 26

    Lake shore model 330 autotuning temperature controller user’s manual 2-10 installation 2.11.2 power up configuration the user may store a model 330 power up (pup) configuration so the model 330 powers up to a user-defined state after power down. Retain heater range, setpoint, gain, reset, units, and...

  • Page 27: Chapter 3

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-1 chapter 3 operation 3.0 general this chapter covers definition of front panel controls (paragraph 3.1), thermometry functions (paragraph 3.2), control functions (paragraph 3.3), interface and miscellaneous functions (...

  • Page 28

    Lake shore model 330 autotuning temperature controller user’s manual 3-2 operation set point: displays or adjusts the control loop temperature setpoint (paragraph 3.3.2). Press and hold this key to access the ramp rate feature, where the user sets the rate at which the temperature setpoint automatic...

  • Page 29

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-3 3.2.1 input type press and hold the input type key to verify internal dip switch settings that determine sensor input type as defined in table 2-1. When factory-configured, the model number corresponds the type of sen...

  • Page 30

    Lake shore model 330 autotuning temperature controller user’s manual 3-4 operation 3.2.5 display filter the filter function reads 10 sequential temperature readings over 5-seconds and displays a running average. It quiets the display, making it more readable when the sensor is exposed to fluctuating...

  • Page 31

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-5 3.2.7 softcal softcal improves the accuracy of a dt-400 series silicon diode sensor. It enables the user to reduce the error between a silicon diode and the standard curve 10 which the controller uses to convert diode...

  • Page 32

    Lake shore model 330 autotuning temperature controller user’s manual 3-6 operation 3.2.7.2 customer performed softcal depending on the desired temperature range, the customer may perform a 2-point or 3-point softcal. This example assumes a 3-point softcal. For 2-point, omit the steps associated with...

  • Page 33

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-7 lake shore dt-400 series silicon diode temperature sensor standard softcal™ calibration precision calibration standard sensors are interchangeable within the published tolerance band. Standard curv e 10 tolerance (acc...

  • Page 34

    Lake shore model 330 autotuning temperature controller user’s manual 3-8 operation 3.3 control functions the following front panel keyboard functions relate to model 330 control: heater (paragraph 3.3.1), setpoint (paragraph 3.3.2), ramp (paragraph 3.3.3), autotune (paragraph 3.3.4), manual (pid) (p...

  • Page 35

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-9 3.3.2.1 voltage resolution (models 330-1x, -3x, and -4x only) use voltage mode for diode input. In voltage mode, the display resolution is 0.0001 volt (v) below 2 volts. For thermocouple input, the display is in milli...

  • Page 36

    Lake shore model 330 autotuning temperature controller user’s manual 3-10 operation 3.3.4.1 initial values of pid parameters in autotune mode initial values of pid parameters in autotune mode are set when the controller is changed from manual to either p, pi or pid control. Initial factory settings ...

  • Page 37

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-11 a system normally takes several time constants to settle into the set point, e.G. The 50 second time constant, if correct for the controlled system, results in a stable set point in about 5 to 10 minutes. The oscilla...

  • Page 38

    Lake shore model 330 autotuning temperature controller user’s manual 3-12 operation zone 01 0 k zone 02 zone 03 zone 04 zone 05 zone 06 zone 07 zone 08 zone 09 zone 10 setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: heater range off low high 0 k he...

  • Page 39

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-13 3.4 interface and miscellaneous functions the following front panel keyboard functions relate to model 330 thermometry or temperature control: baud (paragraph 3.4.1), address (paragraph 3.4.2), local (paragraph 3.4.3...

  • Page 40

    Lake shore model 330 autotuning temperature controller user’s manual 3-14 operation zone 01 0 k zone 02 zone 03 zone 04 zone 05 zone 06 zone 07 zone 08 zone 09 zone 10 setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: setpoint: heater low 0 k heater low heater...

  • Page 41

    Lake shore model 330 autotuning temperature controller user’s manual operation 3-15 3.5 thermocouple controller operation (model 330-4x only) the thermocouple input option allows either channel a, channel b, or both to accommodate thermocouple sensors. The controller supports chromel-aufe (0.07%), c...

  • Page 42

    Lake shore model 330 autotuning temperature controller user’s manual 3-16 operation this page intentionally left blank.

  • Page 43: Chapter 4

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-1 chapter 4 remote operation 4.0 general either of the two computer interfaces provided with the model 330 permit remote operation. The first is the ieee-488 interface (paragraph 4.1). The second is the serial in...

  • Page 44

    Lake shore model 330 autotuning temperature controller user’s manual 4-2 remote operation 4.1.2.1 bus control commands a universal command addresses all devices on the bus. Universal commands include uniline and multiline commands. A uniline command (message) asserts only a single signal line. The m...

  • Page 45

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-3 if the service request is enabled, setting any of these bits causes the model 330 to pull the srq management low to signal the bus controller. These bits reset to zero upon a serial poll of the status byte regi...

  • Page 46

    Lake shore model 330 autotuning temperature controller user’s manual 4-4 remote operation device dependent error (dde) bit (3) – set to indicate a device dependent error. Determine the actual device dependent error by executing the various device dependent queries. Query error (qye) bit (2) – set to...

  • Page 47

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-5 table 4-1. Sample basic ieee-488 interface program ' ieeeexam.Bas example program for ieee-488 interface ' ' this program works with quickbasic 4.0/4.5 on an ibm pc or compatible. ' ' the example requires a pro...

  • Page 48

    Lake shore model 330 autotuning temperature controller user’s manual 4-6 remote operation primary gpib address ........ → 0 secondary gpib address ...... None timeout setting ............. 10sec terminate read on eos ....... Yes set eoi with eos on writes .. Yes type of compare on eos ...... 7-bit e...

  • Page 49

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-7 4.2 serial i/o interface rs-232c is a standard of the electronics industries association (eia) and one of the most common interfaces between a computer and electronic equipment. The customer supplied computer m...

  • Page 50

    Lake shore model 330 autotuning temperature controller user’s manual 4-8 remote operation 4.2.1 serial interface hardware configuration the model 330 operates at two different baud rates: 300 or 1200. Hold the baud key and press the t key to cycle between 300 and 1200. The remaining communication pa...

  • Page 51

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-9 table 4-3 sample basic serial interface program ' serexam.Bas example program for serial interface ' this program works with quickbasic 4.0/4.5 or qbasic on an ibm pc or compatible ' with a serial interface. It...

  • Page 52

    Lake shore model 330 autotuning temperature controller user’s manual 4-10 remote operation 4.3 ieee-488/serial interface command summary the ieee-488/serial interface commands are listed alphabetically in function order. There are five command groups: common commands (paragraph 4.3.2), interface com...

  • Page 53

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-11 4.3.2 common commands common commands are input/output commands defined by the ieee-488 standard and are shared with other instruments complying with the standard. Common commands begin with an asterisk (*). Q...

  • Page 54

    Lake shore model 330 autotuning temperature controller user’s manual 4-12 remote operation q q q q opc? Query operation complete input: *opc? Returned: 1. Format: n[term] remarks: places a “1” in the controller output queue upon completion of all pending selected device operations. Send as the last ...

  • Page 55

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-13 4.3.3 interface commands addr set ieee address. Input: addr [address] [address]: an integer from 1 to 30. Address 0 and 31 are reserved. Returned: nothing remarks: sets the ieee address. The model 330 is facto...

  • Page 56

    Lake shore model 330 autotuning temperature controller user’s manual 4-14 remote operation term? Terminator query. Input: term? Returned: returns the current terminating character type: 0 = carriage return and line feed (cr)(lf eoi ) 1 = line feed and carriage return (lf)(cr eoi ) 2 = line feed (lf ...

  • Page 57

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-15 filt set display filter. Input: filt 0 , or filt 1 returned: nothing remarks: turns display filter on or off: 0 = off, 1 = on. Quiets display by taking a running average of 10 readings. Filt? Display filter qu...

  • Page 58

    Lake shore model 330 autotuning temperature controller user’s manual 4-16 remote operation 4.3.5 control process commands control process commands allow the interface to change any of the model 330 control parameters. Access manual mode pid parameters as well as autotuning status. Clim set control l...

  • Page 59

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-17 rampr set ramp rate in kelvin per minute. Input: rampr xx.X returned: nothing remarks: xx.X is the ramp rate in kelvin per minute between 0 and 99.9. Example: ramp 10[term] instructs the model 330 to make the ...

  • Page 60

    Lake shore model 330 autotuning temperature controller user’s manual 4-18 remote operation setp sets the setpoint in units chosen for control channel. Input: setp xxx.Xx for temperature, or setp x.Xxxx for voltage returned: nothing remarks: for the setpoint parameter, enter a value from 0 to 999.9 f...

  • Page 61

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-19 4.3.6 curve commands curve commands allow users to verify existing factory-added curves or enter or delete user-defined curves over the interface. Acomp set room temperature compensation for channel a. Input: ...

  • Page 62

    Lake shore model 330 autotuning temperature controller user’s manual 4-20 remote operation bcur? Curve number for channel b query. Input: bcur? Returned: xx (an integer from 00 to 31) remarks: returns the currently selected sensor curve number for channel b. Table 3-1 lists sensor curve numbers. Bty...

  • Page 63

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-21 curv (continued) to view a typical output after using this command, see the example under the curv? Command. When entering, omit temperature coefficient, number of points, and endpoints. The model 330 determin...

  • Page 64

    Lake shore model 330 autotuning temperature controller user’s manual 4-22 remote operation ecur edit or add a data point in user curve. Input: ecur xx,y.Yyyyy,zzz.Z returned: nothing remarks: enter the point to be added or edited: xx = curve number from 11 to 31, y.Yyyyy = voltage, and zzz.Z = tempe...

  • Page 65

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-23 4.4 user curve loading program to simplify the loading of a user curve using the serial interface, the following curve loading program is provided. The program will work with quickbasic v4.0/4.5 or qbasic for ...

  • Page 66

    Lake shore model 330 autotuning temperature controller user’s manual 4-24 remote operation '************************************************************************ '* curve loading program * '* this routine will load a curve. Get here by entering "curve" above. * '* note: spacing of the data string...

  • Page 67

    Lake shore model 330 autotuning temperature controller user’s manual remote operation 4-25 below are sample outputs from the program: sample acsii file no. 1 (older drc sensor format) xc06,s00tg120acs2 8333,0.86045,325.0,0.90212,310.0,0.94350,295.0,0.98457,280.0,1. 02532,265.0,1.06566,250.0,1.09231,...

  • Page 68

    Lake shore model 330 autotuning temperature controller user’s manual 4-26 remote operation this page intentionally left blank.

  • Page 69: Chapter 5

    Lake shore model 330 autotuning temperature controller user’s manual service & calibration 5-1 chapter 5 service and calibration 5.0 general this chapter covers several aspects of model 330 service and calibration: general maintenance precautions (paragraph 5.1), electrostatic discharge (paragraph 5...

  • Page 70

    Lake shore model 330 autotuning temperature controller user’s manual 5-2 service & calibration 5.3 rear panel connector definitions figures 5-2 thru 5-4 define serial i/o, analog output, sensor input, and heater output connectors. Figure 5-2. Serial i/o rj-11 rear panel connector details i+ i– v– v+...

  • Page 71

    Lake shore model 330 autotuning temperature controller user’s manual service & calibration 5-3 5.4 ieee-488 interface connector connect to the ieee-488 interface connector on the model 330 rear with cables specified in the ieee-488- 1978 standard document. The cable has 24 conductors with an outer s...

  • Page 72

    Lake shore model 330 autotuning temperature controller user’s manual 5-4 service & calibration 5.5 optional serial interface cable and adapters to aid in serial interface troubleshooting, figures 5-6 thru 5-8 show wiring information for the optional cable assembly and the two mating adapters. Black ...

  • Page 73

    Lake shore model 330 autotuning temperature controller user’s manual service & calibration 5-5 5.6 top of enclosure remove and replace procedure warning: to avoid potentially lethal shocks, turn off controller and disconnect it from ac power line before performing this procedure. Only qualified pers...

  • Page 74

    Lake shore model 330 autotuning temperature controller user’s manual 5-6 service & calibration 5.8 error messages on power up, the model 330 checks internal memory. There are two potential error messages. The first error, er01, indicates an unsuccessful attempt to write and then read the internal no...

  • Page 75

    Lake shore model 330 autotuning temperature controller user’s manual service & calibration 5-7 5.9 changing sensor input type the factory establishes sensor input type and model number before shipping. Configure sensor input type by setting dip switches s1 and s2 on the main controller pcb. To chang...

  • Page 76

    Lake shore model 330 autotuning temperature controller user’s manual 5-8 service & calibration new c-330-u-5-9 figure 5-9. Typical model 330 pcb layout.

  • Page 77

    Lake shore model 330 autotuning temperature controller user’s manual service & calibration 5-9 5.11 model 330-4x (thermocouple) calibration 1. Follow the remove top procedure in paragraph 5.6. 2. A/d calibration: connect v+ lead of voltmeter to tp2 of the main board, and the v– lead to tp1. Adjust t...

  • Page 78

    Lake shore model 330 autotuning temperature controller user’s manual 5-10 service & calibration this page intentionally left blank.

  • Page 79: Chapter 6

    Lake shore model 330 autotuning temperature controller user’s manual options and accessories 6-1 chapter 6 options and accessories 6.0 general this chapter covers model 330 temperature controller model numbers (paragraph 6.1), options (paragraph 6.2), and accessories (paragraph 6.3). 6.1 models two ...

  • Page 80

    Lake shore model 330 autotuning temperature controller user’s manual 6-2 options and accessories 6.2.1 330-51 option the model 330-51 is a special configuration of the model 330-41 that allows temperature measurement and control to 1000 °c with a type k thermocouple. The channel a input is modified ...

  • Page 81

    Lake shore model 330 autotuning temperature controller user’s manual options and accessories 6-3 6.3 accessories accessories are devices that perform a secondary duty as an aid or refinement to the primary unit. Model number description of model 330 accessory 106-009 * heater output connector (dual ...

  • Page 82

    Lake shore model 330 autotuning temperature controller user’s manual 6-4 options and accessories cable length: 4.3 meters (14 feet) c-330-u-6-1 figure 6-1. Model 2001 rj-11 cable assembly 43 mm (1.69 inches) 15.8 mm (0.63 inches) 55 m m ( 2.1 6 i nc hes ) 25 1 c-330-u-6-2.Wmf figure 6-2. Model 2002 ...

  • Page 83

    Lake shore model 330 autotuning temperature controller user’s manual options and accessories 6-5 . Mod el 3 30 tem pera ture con trolle r 1 rack mount ear 107-049 1 2 screw, 6-32 x 1/2 inch 0-035 2 fhms, phillips 3 rack mount support 107-046 1 4 rack mount plate 107-051 1 5 screw, 8-32 x 3/8 inch 0-...

  • Page 84

    Lake shore model 330 autotuning temperature controller user’s manual 6-6 options and accessories 1 rack mount ear 107-049 2 2 screw, 6-32 x 1/2 inch 0-035 6 fhms, phillips 3 front locking bracket 107-042 1 4 rear locking bracket 107-043 2 5 screw, 6-32 x 3/8 inch 0-043 4 phms, phillips additional pa...

  • Page 85: Appendix A

    Lake shore model 330 autotuning temperature controller user’s manual appendix a a-1 appendix a curve tables table a-1. Standard diode and platinum curves breakpoint d curve e1 curve dt-470 curve 10 platinum 100 ohm number temp. (k) v temp. (k) v temp. (k) v temp. (k) Ω Ω Ω Ω equiv.* 1 2 3 4 5 6 7 8 ...

  • Page 86

    Lake shore model 330 autotuning temperature controller user’s manual a-2 appendix a table a-2. Thermocouple curves - chromel versus gold / iron breakpoint chromel vs. Au - 0.03 at % fe chromel vs. Au - 0.07 at % fe number temp. (k) v tc (mv) temp. (k) v tc (mv) 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16...

  • Page 87: Appendix B

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-1 appendix b application notes b1.0 general this appendix includes these lake shore applications notes: 1. Fundamentals for usage of cryogenic temperature controllers – application note ................. Page b-...

  • Page 88

    Lake shore model 330 autotuning temperature controller user’s manual b-2 application notes iii proportional control the block diagram in figure 1 shows a systems in which only proportional control is being used. In this system, the desired control temperature setting (set point) is being compared to...

  • Page 89

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-3 to illustrate the effect of the sensor, in more detail, consider the idealized curve (figure 4) for a lake shore silicon diode which has a nominal sensitivity of -50 mv/k below 30 kelvin and -2.5 mv/k above 30...

  • Page 90

    Lake shore model 330 autotuning temperature controller user’s manual b-4 application notes since the thermal conductivity of cryogenic materials is finite, good practice dictates that the controller power output be the same order of magnitude as the cooling power. If, for example, the cooling power ...

  • Page 91

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-5 the real world revisited since a real cryogenic system has non-zero thermal resistance, the value of the reset is important in setup of the controller. The amount of reset desired is dependent on: (1) the time...

  • Page 92

    Lake shore model 330 autotuning temperature controller user’s manual b-6 application notes vi sensor considerations sensor gain revisited: since a controller will amplify input noise as well as sensor signal, it becomes important to consider sensor performance when designing a complete system. The l...

  • Page 93

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-7 for further reading 1. E. M. Forgan, "on the use of temperature controllers in cryogenics". Cryogenics 14 (1974), pp. 207-214. This is a cogent discussion of the interaction between the electrical and thermal ...

  • Page 94

    Lake shore model 330 autotuning temperature controller user’s manual b-8 application notes standard curve 10 standard curve 10: measurement current = 10 µa ±0.05% t (k) voltage dv/dt (mv/k) t (k) voltage dv/dt (mv/k) t (k) voltage dv/dt (mv/k) 1.40 1.60 1.80 2.00 2.20 2.40 2.60 2.80 3.00 3.20 3.40 3...

  • Page 95

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-9 polynomial representation curve 10 can be expressed by a polynomial equation based on the chebychev polynomials. Four separate ranges are required to accurately describe the curve. Table 1 lists the parameters...

  • Page 96

    Lake shore model 330 autotuning temperature controller user’s manual b-10 application notes dt-470 series temperature sensors installation and operation there are three aspects of using a temperature sensor which are critical to its optimum performance. The first involves the proper electrical and t...

  • Page 97

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-11 dt-470-sd the sd version is the basic package for the dt-470 sensor line from which all other configurations are made using the appropriate adapter. The base of the device has a gold metallized surface and is...

  • Page 98

    Lake shore model 330 autotuning temperature controller user’s manual b-12 application notes dt-470-et / dt-470-mt dt-470-et dt-470-mt both adapters are gold-plated copper hex head bolts with the sd package mounted in a slot on the adapter head. The et adapter screws into a ¼ inch deep, 6-32 threaded...

  • Page 99

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-13 figure 1 four-wire configuration for dt-470 installation sensor operation temperature controllers and thermometer instrumentation manufactured by lake shore cryotronics are designed to be directly compatible ...

  • Page 100

    Lake shore model 330 autotuning temperature controller user’s manual b-14 application notes measurement system induced errors in diode thermometry by john k. Krause and brad c. Dodrill diode temperature sensors are capable of being used at the accuracy level of a few hundredths of a kelvin. However,...

  • Page 101

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-15 there are two simple techniques which can be used to test whether these errors might be present in a measuring system. The first is to connect a capacitor (about 10 µf) in parallel with the diode to act as a ...

  • Page 102

    Lake shore model 330 autotuning temperature controller user’s manual b-16 application notes the measured offset voltages shown in figs. 4 and 6 can be understood by using the well-known result from p-n junction theory: i = i s [exp(ev / nkt) - 1] (1) where i = the forward current through the junctio...

  • Page 103

    Lake shore model 330 autotuning temperature controller user’s manual application notes b-17 the utilization of the small signal model has the advantage of being analytically simple. However, the model does not contain the nonlinearity inherent in the forward biased iv characteristics of a p-n juncti...

  • Page 104

    Lake shore model 330 autotuning temperature controller user’s manual b-18 application notes iv. Concluding remarks noise in any measurement circuit is undesirable and should be eliminated to as great an extent as possible. The first step is to electrically shield all instrumentation and wiring and u...