Lakeshore 231, 231P User Manual

User’s Manual

Model 231 / 231P

Temperature Transmitter

Includes Coverage for:

Model 2308-01 Benchtop Enclosure

Model 2308-12 VMEbus Rackmount Case

For Use With The Following Lake Shore Sensors:

Model DT-414 Unencapsulated Silicon Diode Temperature Sensors

Series DT-420 Miniature Silicon Diode Temperature Sensors

Series DT-470 Silicon Diode Temperature Sensors
Series DT-471 Silicon Diode Temperature Sensors
Series DT-670 Silicon Diode Temperature Sensors
Series PT-100 Platinum Resistance Thermometers

Series TG-120 GaAlAs Diode Temperature Sensors

Lake Shore Cryotronics, Inc.
575 McCorkle Boulevard
Westerville, Ohio 43082-8888 USA

E-Mail Addresses:

[e-mail]
[e-mail]

Visit Our Website:

www.lakeshore.com

Fax: [phone]
Telephone: [phone]

Methods and apparatus disclosed and described herein have been developed solely on company funds of Lake
Shore Cryotronics, Inc. No government or other contractual support or relationship whatsoever has existed which in
any way affects or mitigates proprietary rights of Lake Shore Cryotronics, Inc. in these developments. Methods and
apparatus disclosed herein may be subject to U.S. Patents existing or applied for. Lake Shore Cryotronics, Inc.
reserves the right to add, improve, modify, or withdraw functions, design modifications, or products at any time
without notice. Lake Shore shall not be liable for errors contained herein or for incidental or consequential damages
in connection with furnishing, performance, or use of this material.

Rev. 1.8 P/N 119-021 03 October 2013

Lake Shore Model 231 User’s Manual

LIMITED WARRANTY STATEMENT – WARRANTY PERIOD: THREE (3) YEAR

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
receipt of the Product (the "Warranty Period"). If Lake Shore receives notice of any such defects
during the Warranty Period and the defective Product is shipped freight prepaid back to Lake
Shore, Lake Shore will, at its option, either repair or replace the Product (if it is so defective)
without charge for parts, service labor or associated customary return shipping cost to the
Purchaser. Replacement for the Product may be by either new or equivalent in performance to
new. Replacement or repaired parts, or a replaced Product, will be warranted for only the
unexpired portion of the original warranty or 90 days (whichever is greater).

2. Lake Shore warrants the Product only if the Product has been sold by an authorized Lake Shore
employee, sales representative, dealer or an authorized Lake Shore original equipment
manufacturer (OEM).

3. The Product may contain remanufactured parts equivalent to new in performance or may have
been subject to incidental use when it is originally sold to the Purchaser.

4. The Warranty Period begins on the date of Purchaser's physical receipt of the Product or later
on the date of operational training and verification (OT&V) of the Product if the service is
performed by Lake Shore, provided that if the Purchaser schedules or delays the Lake Shore
OT&V for more than 30 days after delivery then the Warranty Period begins on the 31st day
after Purchaser's physical receipt of the Product.

5. This limited warranty does not apply to defects in the Product resulting from (a) improper or
inadequate installation (unless OT&V services are performed by Lake Shore), maintenance,
repair or calibration, (b) fuses, software, power surges, lightning and non-rechargeable
batteries, (c) software, interfacing, parts or other supplies not furnished by Lake Shore, (d)
unauthorized modification or misuse, (e) operation outside of the published specifications, (f)
improper site preparation or site maintenance (g) natural disasters such as flood, fire, wind, or
earthquake, or (h) damage during shipment other than original shipment to you if shipped
through a Lake Shore carrier.

6. This limited warranty does not cover: (a) regularly scheduled or ordinary and expected
recalibrations of the Product; (b) accessories to the Product (such as probe tips and cables,
holders, wire, grease, varnish, feed throughs, etc.); (c) consumables used in conjunction with
the Product (such as probe tips and cables, probe holders, sample tails, rods and holders,
ceramic putty for mounting samples, Hall sample cards, Hall sample enclosures, etc.); or, (d)
non-Lake Shore branded Products that are integrated with the Product.

7. To the extent allowed by applicable law,, this limited warranty is the only warranty applicable to
the Product and replaces all other warranties or conditions, express or implied, including, but
not limited to, the implied warranties or conditions of merchantability and fitness for a particular
purpose. Specifically, except as provided herein, Lake Shore undertakes no responsibility that
the products will be fit for any particular purpose for which you may be buying the Products. Any
implied warranty is limited in duration to the warranty period. No oral or written information, or
advice given by the Company, its Agents or Employees, shall create a warranty or in any way
increase the scope of this limited warranty. Some countries, states or provinces do not allow
limitations on an implied warranty, so the above limitation or exclusion might not apply to you.
This warranty gives you specific legal rights and you might also have other rights that vary from
country to country, state to state or province to province.

8. Further, with regard to the United Nations Convention for International Sale of Goods (CISC,) if
CISG is found to apply in relation to this agreement, which is specifically disclaimed by Lake
Shore, then this limited warranty excludes warranties that: (a) the Product is fit for the purpose
for which goods of the same description would ordinarily be used, (b) the Product is fit for any
particular purpose expressly or impliedly made known to Lake Shore at the time of the
conclusion of the contract. (c) the Product is contained or packaged in a manner usual for such
goods or in a manner adequate to preserve and protect such goods where it is shipped by
someone other than a carrier hired by Lake Shore.

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 arising from the infringement of
patents or trademarks or violation or copyrights by the Product.

10. THIS WARRANTY IS NOT TRANSFERRABLE. This warranty is not transferrable.

11. Except to the extent prohibited by applicable law, neither Lake Shore nor any of its
subsidiaries, affiliates or suppliers will be held liable for direct, special, incidental, consequential

or other damages (including lost profit, lost data, or downtime costs) arising out of the use,
inability to use or result of use of the product, whether based in warranty, contract, tort or other
legal theory, regardless whether or not Lake Shore has been advised of the possibility of such
damages. Purchaser's use of the Product is entirely at Purchaser's risk. Some countries, states
and provinces do not allow the exclusion of liability for incidental or consequential damages, so
the above limitation may not apply to you.

12. This limited warranty gives you specific legal rights, and you may also have other rights that
vary within or between jurisdictions where the product is purchased and/or used. Some
jurisdictions do not allow limitation in certain warranties, and so the above limitations or
exclusions of some warranties stated above may not apply to you.

Except to the extent allowed by applicable law, the terms of this limited warranty statement do not
exclude, restrict or modify the mandatory statutory rights applicable to the sale of the product to
you.

CERTIFICATION

Lake Shore certifies that this product has been inspected and tested in accordance with its
published specifications and that this product met its published specifications at the time of
shipment. The accuracy and calibration of this product at the time of shipment are traceable to the
United States National Institute of Standards and Technology (NIST); formerly known as the
National Bureau of Standards (NBS), or to a recognized natural standard.

TRADEMARK ACKNOWLEDGEMENT

Manufacturers and sellers claim many designations as trademarks to distinguish their products.
Where those designations appear in this manual and Lake Shore was aware of a trademark claim,
the designations appear in initial capital letters with a ™ or

®

symbol.

Apiezon® is a trademark of Biddle Instruments.

CalCurve™, Carbon-Glass™, Cernox™, Duo-Twist™, High-Temperature Cernox™, Quad­Lead™, Quad-Twist™, Rox™, SoftCal™, and Thermox™ are trademarks of Lake Shore

Cryotronics, Inc.
Teflon® is a trademark of DuPont De Nemours.

Copyright © 1993, 1998-99, 2001, 2004, 2012-13 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
otherwise, without express written permission of Lake Shore.

Rev. 1.8 P/N 119-021 03 October 2013

Lake Shore Model 231 User’s Manual

i

Lake Shore Model 231 User’s Manual

TABLE OF CONTENTS

Chapter/Paragraph Title Page

1 INTRODUCTION .......................................................................... 1-1

1.0 General .......................................................................... 1-1

1.1 Model 231 System Description ...................................... 1-1

1.2 Single Enclosure Case Description ................................ 1-6

1.3 Multiple Unit Enclosure Case Description ...................... 1-7

2 INSTALLATION ........................................................................... 2-1

2.0 General .......................................................................... 2-1

2.1 Inspection and Unpacking .............................................. 2-1

2.2 Repackaging For Shipment ........................................... 2-1

2.3 Sensor Installation Recommendations........................... 2-2

2.3.1 Two-Lead vs. Four-Lead Measurements .................... 2-2

2.3.1.1 Two-Lead Measurements ....................................... 2-2

2.3.1.2 Four-Lead Measurements ...................................... 2-3

2.3.2 Connecting Leads To The Sensor .............................. 2-3

2.3.3 Sensor Mounting ........................................................ 2-3

2.3.4 Measurement Errors Due To AC Noise ...................... 2-4

2.4 Sensor Curve Definition ................................................. 2-5

2.5 Power Connections ........................................................ 2-6

3 OPERATION ................................................................................ 3-1

3.0 General .......................................................................... 3-1

3.1 PCB DIP Switch Settings ............................................... 3-1

3.2 Output to Temperature Conversion ............................... 3-2

4 SERVICE ..................................................................................... 4-1

4.0 General .......................................................................... 4-1

4.1 General Troubleshooting ............................................... 4-1

4.1.1 No Output (On-Board LED Off) .................................. 4-1

4.1.2 Output Stops Before Reaching Upper Limit ............... 4-1

4.1.3 Output Is Incorrect Value (Small Error) ...................... 4-1

4.1.4 Output Is Incorrect Value (Large Error) ...................... 4-2

4.2 Model 231 Connector Definitions ................................... 4-2

4.3 Calibration ...................................................................... 4-3

4.3.1 Test Equipment Required ........................................... 4-3

4.3.2 Reference Calibration ................................................. 4-4

4.3.3 Output Calibration ...................................................... 4-5

Table of Contents

ii

Lake Shore Model 231 User’s Manual

TABLE OF CONTENTS (Continued)

Chapter/Paragraph Title Page

5 OPTIONS AND ACCESSORIES ................................................. 5-1

5.0 General .......................................................................... 5-1

5.1 Enclosures ..................................................................... 5-1

5.2 Options........................................................................... 5-1

5.3 Accessories .................................................................... 5-2

5.4 Wires .............................................................................. 5-2

5.5 Sensors .......................................................................... 5-3

5.6 Special Equipment ......................................................... 5-3

APPENDIX A – MODEL 231 CURVE TABLES ................................. A-1

APPENDIX B – GLOSSARY OF TERMINOLOGY ............................ B-1

Figure No. Title Page

1-1 Typical Model 231 Front Panel.............................................. 1-2

1-2 Single Enclosure Case Physical Dimensions ........................ 1-6

1-3 Multiple Unit Case Physical Dimensions ............................... 1-8

2-1 Typical Wall Plug-In Power Supply ....................................... 2-7

3-1 Model 231 DIP Switch (S1) ................................................... 3-1

4-1 Front Panel Connectors J2 & J3 Details ............................... 4-2

4-2 VMEbus Connector J1 Details .............................................. 4-3

4-3 Model 231 PCB Layout ......................................................... 4-4

Table No. Title Page

1-1 Model 231 Input Specifications ............................................. 1-3

1-2 Model 231P Input Specifications ........................................... 1-4

1-3 Model 231 & 231P Output Specifications .............................. 1-5

1-4 Model 2308-12 VMEbus Rackmount Case Specs ................ 1-7

2-1 Effect of Current Variation on Diode Temperature ................ 2-5

2-2 Typical DT-470 dV/dI Values for Selected Temps ................. 2-5

3-1 Conversion Parameters for Temperature in K ....................... 3-2

A-1 Lake Shore Standard Diode Curves ......................................A-1

A-2 Series PT-100 Platinum Resistance Curve ...........................A-2

LIST OF ILLUSTRATIONS

LIST OF TABLES

Table of Contents

Lake Shore Model 231 User’s Manual

CHAPTER 1

INTRODUCTION

1.0 GENERAL

Lake Shore Cryotronics designed and manufactures the Model 231 in the
United States of America. In general, reference to the Model 231 means
both the Model 231 and 231P. Specific references are made where
appropriate. This chapter provides a general description with specifications
in Paragraph 1.1, single-enclosure case description in Paragraph 1.2, and
multiple-unit enclosure case description in Paragraph 1.3.

We welcome comments on this manual. Although we try to keep it error-free,
some may occur. To report an error, describe it briefly and include the
appropriate paragraph, figure, table, and page number. Send comments to
Lake Shore Cryotronics, Attn: Technical Publications, 575 McCorkle Blvd.,
Westerville, Ohio 43082-8888. This manual is subject to change without
notice.

1.1 MODEL 231 GENERAL DESCRIPTION

The Model 231 Temperature Transmitter is available as a stand-alone unit or
for use within either of two enclosures: a Model 2308-1 single-space
enclosure, or a Model 2308-12 rackmount case that holds up to 12 units.

The Model 231 Temperature Transmitter sends temperature data from its
position near a sensor to a data acquisition channel or strip chart recorder. It
operates with Silicon diode or Gallium-Aluminum-Arsenide (GaAlAs) diode
sensors. Lake Shore Silicon diode sensors are accurate over a wide
cryogenic temperature range and are interchangeable for some applications.
The Lake Shore Series TG-120 GaAlAs diodes operate in a low to moderate
magnetic field. Excited with a 10 µA current source from the Model 231, the
sensors produce a voltage that depends on temperature. A microcontroller
reads the voltage through an A/D converter and translates it into
temperature. Either the standard temperature curve or an optional
CalCurve™ relates voltage to temperature (the Series TG-120 requires a
CalCurve).

The Model 231P uses a Series PT-100 Platinum Thermometer. The Model
231P excites the sensor with a 500 µA current to produce a measurable
signal. Either the standard platinum curve (DIN 437600) or a CalCurve is
used for temperature conversion.

Introduction 1-1

Figure 1-1. Typical

Model 231 Front Panel

Lake Shore Model 231 User’s Manual

Once the Model 231 obtains temperature data, it
transmits it as a current from 4 to 20 mA. The
current output changes linearly with sensor
temperature. Output scale depends on the selected
temperature range. Several switch selected ranges
are available. For highest accuracy and sensitivity,
set the output for a narrow temperature band. An
optional 0 to 20 mA output is also available to
convert output to a voltage reading scaled from zero.
A 500  ±0.02% precision resistor is provided for
this purpose. This resistor produces the maximum
full-scale output of 10 V.

A single +5 VDC supply powers Model 231 circuitry.
The outputs are isolated so several 231s can
operate from the same supply without interference.
The +5 VDC can also be supplied from the pins on
the VME bus connector.

Mechanical mounting is easy because the
Model 231 is built on a standard size VME card.
It fits directly into a single height (3U) VME card
holder. The transmitter does not use the electrical
bus format, only its physical shape and power
supply.

1-2 Introduction

Thermometry:

Number of Inputs: One input
Measurement Type: Four-lead differential
Sensor Type: Silicon diode, GaAlAs diode (to 5V)
Sensor Temp. Coefficient: Negative
Sensor Units: Volt (V)
Input Range: 0 – 5 volts
Sensor Excitation: 10 µA ±0.1% DC current
Update Rate: 5 readings per second
CalCurve Storage: 1 curve, loaded in PROM at factory

Example Lake Shore Sensor: DT-470-CO

Temperature Range: 1.4 K – 325 K with DT-470
Standard Curve: Curve 10
Typical Sensor Sensitivity: –30 mV/K at 4.2 K

–1.9 mV/K at 77.35 K
–2.4 mV/K at 300 K

Measurement Resolution:

Sensor Units: 76.3 µV
Temp. Equivalence: 2.5 mK at 4.2 K

40 mK at 77.35 K
32 mK at 300 K

Measurement Accuracy:

Sensor Units: ±75 µV ±0.01% of reading
Temp. Accuracy *: ±0.07 K at 4.2 K

±0.16 K at 77.35 K
±0.12 K at 300 K

* DT-470-CO with 8001 CalCurve.

Measurement Temperature Coefficient:

Sensor Units: 0.0006% of voltage reading per °C
Temp. Equivalence: 3 mK/°C at 4.2 K

3 mK/°C at 77.35 K

1.2 mK/°C at 300 K

Typical Performance With Series TG-120 Sensor:

Similar to selected example diode sensor with improved
measurement resolution and temperature resolution at
temperatures of 4 K to 50 K. Sensor voltage must not
exceed 5 V at lowest operating temperature.

Lake Shore Model 231 User’s Manual

Table 1-1. Model 231 Input Specifications

Introduction 1-3

Thermometry:

Number of Inputs: One input
Measurement Type: Four-lead differential
Sensor Type: Platinum
Sensor Temp. Coefficient: Positive
Sensor Units: Ohm ()
Input Range: 0 – 312 
Sensor Excitation: 500 µA ±0.02% DC current
Update Rate: 5 readings per second.
CalCurve Storage: 1 curve, loaded in PROM at factory.

Example Lake Shore Sensor: PT-103

Temperature Range: 14 K – 873 K with PT-103
Standard Curve: DIN 43760

Typical Sensor Sensitivity: 0.19 /K @ 30 K

0.42 /K @ 77.35 K

0.39 /K @ 300 K

0.34 /K typical up to 800 K

Measurement Resolution:

Sensor Units: 4.8 m
Temp. Equivalence: 22 mK at 30 K

11 mK at 77.35 K
13 mK at 300 K
14 mK typical up to 800 K

Measurement Accuracy:

Sensor Units: Ohms ()
Temp. Accuracy: ±0.2 K at 30 K

±0.15 K at 77.35 K
±0.3 K at 300 K
±0.7 K typical up to 800 K

Measurement Temperature Coefficient:

Sensor Units: 0.002% of voltage reading per °C
Temp. Equivalence: 0.4 mK/°C at 30 K

1 mK/°C at 77.35 K
6 mK/°C at 300 K
18 mK/°C at 800 K

Magnetic Field Use: Up to 19 teslas for T > 30 K.

Lake Shore Model 231 User’s Manual

Table 1-2. Model 231P Input Specifications

1-4 Introduction

Output:

Number of Outputs: One
Output Type: Current source, isolated from power source but not

sensor input

Output Range: 4 – 20 mA or 0 – 20 mA (for 0 – 10 V with provided
500 , 0.02%, 25 ppm resistor)

Output Compliance: 10 V (500  max load)
Output Temperature Ranges: 0 – 20 K, 0 – 100 K, 0 – 200 K,

0 – 325 K, 0 – 475 K, and 0 – 1000 K

4 – 20 mA Output:

Output Resolution:

Current: ±1.22 µA ±0.006% of full scale
Temp. Equivalence: 0–20 K = 1.5 mK 0–325 K = 24.8 mK
0–100 K = 7.6 mK 0–475 K = 36.2 mK
0–200 K = 15.3 mK 0–1000 K = 76.3 mK

Output Accuracy:

Current: ±2 µA ±0.01% of full scale
Temp. Equivalence: 0–20 K = 2.5 mK 0–325 K = 41 mK

0–100 K = 12.5 mK 0–475 K = 59 mK
0–200 K = 25 mK 0–1000 K = 125 mK

Output Temperature Coefficient:

Current (% output/°C ambient): ±0.0055%/°C
Temp. Equivalence: 0–20 K = 1 mK/°C 0–325 K = 18 mK/°C

0–100 K = 6 mK/°C 0–475 K = 26 mK/°C
0–200 K = 12 mK/°C 0–1000 K = 55 mK/°C

0 – 20 mA Output (0-10 V w/500 , 0.02% Load Resistor):

Output Resolution:

Voltage: 0.6 mV ±0.006% of full scale
Temp. Equivalence: 0–20 K = 1.2 mK 0–325 K = 19.8 mK

0–100 K = 6.1 mK 0–475 K = 29 mK
0–200 K = 12.2 mK 0–1000 K = 61 mK

Output Accuracy:

Voltage: ±3 mV ±0.03% of full scale
Temp. Equivalence: 0–20 K = 6 mK 0–325 K = 98 mK

0–100 K = 30 mK 0–475 K = 143 mK
0–200 K = 60 mK 0–1000 K = 300 mK

Output Temperature Coefficient:

Voltage (% Output/°C ambient): ±0.008%/°C
Temp. Equivalence: 0–20 K = 2 mK/°C 0–325 K = 26 mK/°C

0–100 K = 8 mK/°C 0–475 K = 38 mK/°C
0–200 K = 16 mK/°C 0–1000 K = 80 mK/°C

Lake Shore Model 231 User’s Manual

Table 1-3. Model 231 and 231P Output Specifications

Introduction 1-5