Lake Shore 234 User manual

Rev. 1.7 P/N 119-026 1 March 2016
User’s Manual
Model 234
Temperature Transmitter
and
Model 234D
Temperature Transmitter/Monitor
Includes Coverage for:
Model 2308-01 Benchtop Enclosure
Model 2308-12 VMEbus Rackmount Case
For Use with the Following Lake Shore Sensors:
Series CGR Carbon-Glass Resistance Temperature Sensors
Series CX Cernox™ Resistance Temperature Sensors
Series GR-200 Germanium Resistance 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.
reservestherightto add, improve,modify,orwithdrawfunctions,designmodifications,orproductsat any timewithout
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.

Lake Shore Model 234/234D User’s Manual
A
LIMITED WARRANTY STATEMENT – WARRANTY PERIOD: ONE (1) YEAR
1. Lake Shore warrants that this Lake Shore product (the “Product”) will be free from defects in materials
and workmanship for the Warranty Period specified above (the “Warranty Period”). If Lake Shore
receives notice of any such defects during the Warranty Period and the Product is shipped freight
prepaid, Lake Shore will, at its option, either repair or replace the Product if it is so defective without
charge to the owner for parts, service labor or associated customary return shipping cost. Any such
replacement for the Product may be either new or equivalent in performance to new. Replacement or
repaired parts 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 it has been sold by an authorized Lake Shore employee, sales
representative, dealer or original equipment manufacturer (OEM).
3. The Product may contain remanufactured parts equivalent to new in performance or may have been
subject to incidental use.
4. The Warranty Period begins on the date the Product ships from Lake Shore’s plant.
5. This limited warranty does not apply to defects in the Product resulting from (a) improper or inadequate
maintenance, repair or calibration, (b) fuses, software 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 or (f) improper site preparation or
maintenance.
6. To the extent allowed by applicable law, the above warranties are exclusive and no other warranty or
condition, whether written or oral,is expressed or implied. Lakeshore specifically disclaims anyimplied
warranties or conditions of merchantability, satisfactory quality and/or fitness for a particular purpose
with respect to the product. 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.
7. To the extent allowed by applicable law, the remedies in this warranty statement are your sole and
exclusive remedies.
8. Except to the extent prohibited by applicable law, in no event will lake shore or any of its subsidiaries,
affiliates or suppliers be 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, and whether or not lake shore
has been advised of the possibility of such damages. Your use of the Product is entirely at your own
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.
9. Except to the extent allowed by applicable law, the terms of this limited warranty statement do not
exclude, restrict or modify, and are in addition to, 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™, Quad-Lead™,
Quad-Twist™, Rox™, SoftCal™, and Thermox™ are trademarks of Lake Shore Cryotronics, Inc.
Teflon®is a trademark of DuPont De Nemours.
Copyright © 1993, 1995, 1997, 1999, 2003-04, 2009, and 2016 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 the express
written permission of Lake Shore.

Lake Shore Model 234/234D User’s Manual
Table of Contents i
TABLE OF CONTENTS
Chapter/Paragraph Title Page
1 INTRODUCTION..............................................................................1-1
1.0 General ..........................................................................1-1
1.1 Model 234 General Description......................................1-1
1.2 Model 234D General Description ...................................1-3
1.3 Model 2308-1 Enclosure Description..............................1-8
1.4 Model 2308-12 Case Description...................................1-8
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 Sensor Mounting.........................................................2-2
2.3.2 Connecting Leads To The Sensor..............................2-3
2.3.3 Four-Lead Measurements ..........................................2-3
2.3.4 Proper Shielding Techniques......................................2-4
2.4 Sensor Measurement.....................................................2-4
2.4.1 CalCurve.....................................................................2-5
2.5 Power Connections........................................................2-5
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
3.3 Output to Log(R) Conversion .........................................3-3
4 REMOTE OPERATION ...................................................................4-1
4.0 General ..........................................................................4-1
4.1 Serial Interface...............................................................4-1
4.1.1 Serial Interface Connections.......................................4-1
4.1.2 Serial Interface Operation...........................................4-2
4.1.3 QuickBasic Programming Considerations ..................4-3
4.1.4 QuickBasic Sample Program......................................4-4
4.2 Serial Interface Command Summary .............................4-5
5 SERVICE .........................................................................................5-1
5.0 General ..........................................................................5-1
5.1 General Troubleshooting................................................5-1
5.1.1 No Output (On-Board LED Off)...................................5-1
5.1.2 Output Stops Before Reaching Upper Limit................5-1
5.1.3 Resistance Readings Are Incorrect ............................5-1
5.1.4 Open Condition...........................................................5-1
5.2 Model 234 Connectors ...................................................5-2
5.3 CalCurve Field Installation .............................................5-3

Lake Shore Model 234/234D User’s Manual
ii Table of Contents
Chapter/Paragraph Title Page
5.4 Calibration..................................................................... 5-5
5.4.1 Required Equipment.................................................. 5-6
5.4.2 Preparation and General Test.................................... 5-6
5.4.3 Calibration With Range Switches............................... 5-7
5.4.4 Calibration With Serial Interface Commands ............. 5-9
5.4.5 Calibration Verification..............................................5-11
6 OPTIONS AND ACCESSORIES .................................................... 6-1
6.0 General.......................................................................... 6-1
6.1 Enclosures..................................................................... 6-1
6.2 Options.......................................................................... 6-1
6.3 Accessories................................................................... 6-2
6.4 Wires............................................................................. 6-2
6.5 Sensors......................................................................... 6-3
6.6 Special Equipment ........................................................ 6-3
LIST OF ILLUSTRATIONS
Figure No. Title Page
1-1 Typical Model 234 Front Panel ................................................ 1-3
1-2 Model 234D Dimensions & Front Panel ................................... 1-4
1-3 Model 2308-1 Enclosure Physical Dimensions ........................ 1-9
1-4 Model 2308-12 Case Physical Dimensions.............................1-10
2-1 Typical Model 234 to Sensor Connections............................... 2-3
2-2 Typical Wall Plug-In Power Supply .......................................... 2-6
3-1 Model 234 DIP Switch (S1) Settings........................................ 3-1
4-1 Serial I/O (RJ11) Connector Pin Definitions............................. 4-1
4-2 Serial Interface Connections.................................................... 4-2
5-1 Front Panel Connector Details................................................. 5-2
5-2 VMEbus Connector Details...................................................... 5-3
5-3 Model 234 PCB Layout ............................................................ 5-4
LIST OF TABLES
Table No. Title Page
1-1 Model 234 Specifications ......................................................... 1-5
1-2 Model 2308-12 Case Specifications......................................... 1-8
3-1 Conversion Parameters for Temperature in K.......................... 3-2
4-1 Serial Interface Specifications.................................................. 4-1

Lake Shore Model 234/234D User’s Manual
Introduction 1-1
CHAPTER 1
INTRODUCTION
1.0 GENERAL
The Model 234 is designed and manufactured in the USA by Lake Shore
Cryotronics, Inc. In general, references to the Model 234 applies to both the
Model 234 Transmitter and 234D Transmitter/Monitor. Specific references
are made where appropriate. This chapter provides a General Description of
the Model 234 in Paragraph 1.1, Model 234D General Description in
Paragraph 1.2, Model 2308-1 Enclosure Description in Paragraph 1.3, and
Model 2308-12 Case Description in Paragraph 1.4.
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 234 GENERAL DESCRIPTION
The Model 234 Temperature Transmitter sends temperature data from its
position near a sensor to a data acquisition channel or strip chart recorder.
A Model 234D also displays the temperature (or resistance).
The Model 234 operates with Cernox™, Carbon-Glass, Germanium, or other
resistance temperature sensors. The Lake Shore CGR Series Carbon-Glass
resistance temperature sensors are the best choice for a highly reproducible
sensor from 1.4 K to 325 K and above in magnetic fields up to 19 tesla or
higher. The Lake Shore GR Series Germanium resistance temperature
sensors are recognized “secondary standard thermometers” used in
temperature measurement up to about 100 K for over 30 years. Sensitivity
for both devices increases rapidly with decreasing temperature (both devices
are classified according to their 4.2 K resistance value).
Cernox, Carbon-Glass, and Germanium sensing elements are suspended in
a strain-free mounting which causes the thermal path through the connecting
leads, making measurement method and mounting critical to accurate
temperature measurements.
The Model 234 excites the sensor with a constant voltage of 10 mV or less
to minimize the effects of sensor self-heating at low temperatures.