Lake Shore 234, Руководство пользователя

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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.