Lake Shore 102 User manual

Rev. 1.2 P/N 119-014 9 September 2002
User’s Manual
Model 102
Current Source
Lake Shore Cryotronics, Inc.
575 McCorkle Boulevard
Westerville, Ohio 43082-8888 USA
E-Mail Addresses:
[e-mail]
[e-mail]
Internet Addresses:
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.

Lake Shore Model 102 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 and workmanship for a period of 12 months
from the date of shipment. During the warranty period, under authorized return of
instruments or component parts to Lake Shore freight prepaid, the company will
repair, or at its option replace, any part found to be defective in material or
workmanship, without charge to the Owner for parts, service labor, or associated
customary shipping cost. Replacement or repaired parts will be warranted for only the
unexpired portion of the original warranty or 90 days (whichever is greater).
All products are thoroughly tested and calibrated to published specifications prior to
shipment. Calibration Certifications are offered for 12-month periods only. Where such
documentation must be updated, a re-certification service is offered by Lake Shore at
a reasonable cost.
LIMITATION OF WARRANTY
This warranty is limited to Lake Shore products purchased and installed in the United
States, or Internationally through our approved distribution agents. This same
protection will extend to any subsequent owner during the warranty period. It does not
apply to damage resulting from improper or inadequate maintenance, unauthorized
modification or misuse, or operation outside of the environmental specifications. It
does not apply to damage caused by accident, misuse, fire, flood, or acts of God, or
from failure to properly install, operate, or maintain the product in accordance with the
printed instruction provided.
This warranty is in lieu of any other warranties, expressed or implied, including
merchantability or fitness for a particular purpose, which are expressly excluded. The
owner agrees that Lake Shore’s liability with respect to this product shall be set forth in
this warranty, and incidental or consequential damages are expressly excluded.
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, 1997, 1999, and 2002 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 102 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 102 System Description................................... 1-1
1.2 Handling Liquid Helium and Liquid Nitrogen .............. 1-3
1.2.1 Handling Cryogenic Storage Dewars...................... 1-3
1.2.2 LHe and LN2Safety Precautions ............................ 1-3
1.2.3 Recommended First Aid ......................................... 1-4
1.3 Electrostatic Discharge............................................... 1-4
1.3.1 Identifying ESDS Components ............................... 1-5
1.3.2 Handling ESDS Components ................................. 1-5
1.4 Safety Summary......................................................... 1-5
1.5 Safety Symbols .......................................................... 1-6
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 Power and Ground Requirements.............................. 2-2
2.4 Sensor Installation Recommendations....................... 2-2
2.4.1 Connecting Leads to the Sensor ............................ 2-3
2.4.2 Sensor Mounting..................................................... 2-3
2.4.3 Measurement Errors Due To AC Noise .................. 2-4
3 OPERATION................................................................................ 3-1
3.0 General ...................................................................... 3-1
3.1 Front Panel Features and Functions .......................... 3-1
3.2 Operational Notes ...................................................... 3-2
4 SERVICE ..................................................................................... 4-1
4.0 General ...................................................................... 4-1
4.1 Output Current Programming ..................................... 4-1
4.2 Calibration .................................................................. 4-1
4.2.1 Current Calibration Using DC Amp Range ............. 4-2
4.2.2 Current Calibration Using DC Volt Range............... 4-3

Lake Shore Model 102 User’s Manual
ii Table of Contents
LIST OF ILLUSTRATIONS
Figure No. Title Page
1-1 Typical Cryogenic Storage Dewar ............................................1-3
3-1 Model 102 Front Panel .............................................................3-2
3-2 Typical Model 102 Application ..................................................3-2
4-1 Model 102 PCB Layout............................................................. 4-2
LIST OF TABLES
Table No. Title Page
1-1 Model 102 Specifications..........................................................1-2

Lake Shore Model 102 User’s Manual
Introduction 1-1
CHAPTER 1
INTRODUCTION
1.0 GENERAL
Lake Shore Cryotronics designed and manufactured the Model 102
Current Source in the USA. This chapter covers a general description in
Paragraph 1.1, Handling Liquid Helium and Liquid Nitrogen in
Paragraph 1.2, Electrostatic Discharge in Paragraph 1.3, Safety
Summary in Paragraph 1.4, and Safety Symbols in Paragraph 1.5.
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 102 GENERAL DESCRIPTION
The Model 102 is a precision DC current source which provides excellent
performance at low cost. The factory pre-sets output current to 10 µA, but
the unit may be reprogrammed at any value between 1 µA and 1 mA by
changing a resistor inside the instrument.
The Model 102 has a compliance voltage of 8 Volts, allowing it to be used as
an excitation source in a variety of diode sensor applications. A compliance
LED visually indicates unit operation within specification.
The Model 102 provides a constant current through the load (sensor)
connected across the output terminals. It monitors the voltage across the
sensor and derives a corresponding temperature from the response curve
supplied with the sensor.
An external AC wall-mount transformer supplies power to the unit. There
are two 12 VAC wall mount transformers available for the Model 102: a 120
VAC to 12 VAC transformer for a 90 –130 VAC input, and a 220 VAC to 12
VAC transformer for a 200 –250 VAC input. Specify the supply type to match
the AC line voltage when ordering.

Lake Shore Model 102 User’s Manual
1-2 Introduction
Table 1-1. Model 102 Specifications
Output Current: 10 µA factory set; internally programmable
from 1 µA to 1 mA.
Accuracy: 0.05% of output at 10 µA
Temperature Coefficient: 0.005% per °C
Compliance Voltage: 8 volts
AC Current Ripple: Less than 0.01% of scale +1 nA (RMS) in a
properly shielded system
Line Regulation: Less than 0.01% change in output for
10% change in line voltages within specified range
Load Regulation: Less than 0.01% change in output current
from 1 to 100% of compliance voltage
Connections: Current output via standard banana jacks
Ambient Temperature Range: 15 –35 °C (59 –95 °F)
Power: 90 –125 or 210 –250 VAC, 50/60 Hz,
External Wall Mount AC Transformer
Size: 95 × 33 × 158 mm (3.7 × 1.3 × 6.2 inches)
Weight: 0.3 kilograms (0.7 pounds)
NOTES
1. Product Specifications are subject to change without notice.
2. The electrical specifications given are for a unit operating at the
factory at current output of 10 µA; a different output current may
affect some specifications.

Lake Shore Model 102 User’s Manual
Introduction 1-3
1.2 HANDLING LIQUID HELIUM AND LIQUID NITROGEN
Helium and Nitrogen are colorless, odorless, and tasteless gases. They
liquefy when properly cooled. Liquid Helium (LHe) and liquid nitrogen (LN2)
may be used in conjunction with the Model 102. Although not explosive,
there are certain safety considerations in the handling of LHe and LN2.
1.2.1 Handling Cryogenic Storage Dewars
Operate all cryogenic containers (dewars) in
accordance with manufacturer instructions. Safety
instructions are normally posted on the side of
each dewar. Keep cryogenic dewars in a well-
ventilated place, protected from the weather, and
away from heat sources. Figure 1-1 shows a
typical cryogenic dewar.
1.2.2 LHe and LN2Safety Precautions
Transfer LHe and LN2and operate storage dewar
controls in accordance with manufacturer/supplier
instructions. During transfer, follow all safety
precautions written on the storage dewar and
recommended by the manufacturer.
WARNING
• Liquid helium is a potential asphyxiant and can cause rapid
suffocation without warning. Store and use in an adequately
ventilated area. DO NOT vent the container in confined spaces. DO
NOT enter confined spaces where gas may be present unless area
is well-ventilated. If inhaled, remove to fresh air. If not breathing,
give artificial respiration. If breathing is difficult, give oxygen. Get
medical attention.
• Liquid helium can cause severe frostbite to exposed body parts. DO
NOT touch frosted pipes or valves. For frostbite, consult a
physician immediately. If a physician is unavailable, warm the
affected parts with water that is near body temperature.
Two essential safety aspects of handling LHe are adequate ventilation and
eye and skin protection. Although helium and nitrogen gases are non-toxic,
they are dangerous because they replace air in a normal breathing
atmosphere. Liquid helium is an even greater threat because a small amount
of liquid evaporates to create a large amount of gas. Store and operate
cryogenic dewars in open, well-ventilated areas.
NON-
MAGNETIC
KEEP
UPRIGHT
LIQUID
HELIUM
NON-
FLAMMABLE
Figure 1-1. Typical
Cryogenic Dewar

Lake Shore Model 102 User’s Manual
1-4 Introduction
When transferring LHe and LN2, protect eyes and skin from accidental
contact with liquid or the cold gas issuing from it. Protect eyes with full face
shield or chemical splash goggles; safety glasses (even with side shields)
are inadequate. Always wear special cryogenic gloves (Tempshield
CryoGloves®or equivalent) when handling anything that is, or may have
been, in contact with the liquid or cold gas, or with cold pipes or equipment.
Wear long sleeve shirts and cuffless trousers long enough to prevent liquid
from entering shoes.
1.2.3 Recommended First Aid
Post an appropriate Material Safety Data Sheet (MSDS) obtained from the
manufacturer/distributor at every site that stores and uses LHe and LN2. The
MSDS specifies symptoms of overexposure and first aid.
If a person exhibits symptoms of asphyxia such as headache, drowsiness,
dizziness, excitation, excessive salivation, vomiting, or unconsciousness,
remove to fresh air. If breathing is difficult, give oxygen. If breathing stops,
give artificial respiration. Call a physician immediately.
If exposure to cryogenic liquids or cold gases occurs, restore tissue to
normal body temperature (98.6 °F) by bathing it in warm water not
exceeding 105 °F (40 °C). DO NOT rub the frozen part, either before or after
rewarming. Protect the injured tissue from further damage and infection and
call a physician immediately. Flush exposed eyes thoroughly with warm
water for at least 15 minutes. In case of massive exposure, remove clothing
while showering with warm water. The patient should not drink alcohol or
smoke. Keep warm and rest. Call a physician immediately.
1.3 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 induced by an
electrostatic field. The low-energy source that most commonly destroys
Electrostatic Discharge Sensitive (ESDS) devices is the human body, which
generates and retains static electricity. Simply walking across a carpet in low
humidity may generate up to 35,000 volts of static electricity.
Current technology trends toward greater complexity, increased packaging
density, and thinner dielectrics between active elements, which results in
electronic devices with even more ESD sensitivity. Some electronic parts are
more ESDS than others. ESD levels of only a few hundred volts may
damage electronic components such as semiconductors, thick and thin film
resistors, and piezoelectric crystals during testing, handling, repair, or
assembly. Discharge voltages below 4000 volts cannot be seen, felt, or
heard.

Lake Shore Model 102 User’s Manual
Introduction 1-5
1.3.1 Identifying ESDS Components
Below are some industry symbols used to label components as ESDS:
1.3.2 Handling ESDS Components
Observe all precautions necessary to prevent damage to ESDS components
before installation. Bring the device and everything that contacts it to ground
potential by providing a conductive surface and discharge paths. At a
minimum, observe these precautions:
1. De-energize or disconnect all power and signal sources and loads used
with unit.
2. Place unit on a grounded conductive work surface.
3. Ground technician through a conductive wrist strap (or other device)
using 1 MΩseries resistor to protect operator.
4. Ground any tools, such as soldering equipment, that will contact unit.
Contact with operator's hands provides a sufficient ground for tools that
are otherwise electrically isolated.
5. Place ESDS devices and assemblies removed from a unit on a
conductive work surface or in a conductive container. An operator
inserting or removing a device or assembly from a container must
maintain contact with a conductive portion of the container. Use only
plastic bags approved for storage of ESD material.
6. Do not handle ESDS devices unnecessarily or remove from the
packages until actually used or tested.
1.4 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 manual violates safety standards of
design, manufacture, and intended instrument use. Lake Shore Cryotronics,
Inc. assumes no liability for Customer failure to comply with these
requirements.
Ground The Instrument
To minimize shock hazard, connect instrument chassis and cabinet to an
electrical ground. The instrument comes with a 3-conductor AC power cable.
Plug it into an approved three-contact electrical outlet or use a three-contact
adapter with the green ground wire firmly secured to an electrical ground
(safety ground) at the power outlet. The power cable jack and mating plug
meet Underwriters Laboratories (UL) and International Electrotechnical
Commission (IEC) safety standards.

Lake Shore Model 102 User’s Manual
1-6 Introduction
Do Not Operate In An Explosive Atmosphere
Do not operate the instrument in the presence of flammable gases or fumes.
Operation of any electrical instrument in such an environment constitutes a
definite safety hazard.
Keep Away From Live Circuits
Operating personnel must not remove instrument covers. Refer component
replacement and internal adjustments to qualified maintenance personnel.
Do not replace components with power cable connected. To avoid injuries,
always disconnect power and discharge circuits before touching them.
Do Not Substitute Parts Or Modify Instrument
Do not install substitute parts or perform any unauthorized modification to
the instrument. Return the instrument to an authorized Lake Shore
Cryotronics, Inc. representative for service and repair to ensure that safety
features are maintained.
1.5 SAFETY SYMBOLS