Lake Shore Model 340 Temperature Controller User’s Manual
Table of Contents
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TABLE OF CONTENTS
Chapter/Paragraph Title
Page
1 INTRODUCTION .................................................................................................................................................... 1-1
1.0 GENERAL ......................................................................................................................................... 1-1
1.1 TEMPERATURE
CONTROL SYSTEM ............................................................................................. 1-2
1.2
TEMPERATURE CONTROL SYSTEM WITH THE MODEL 340 ...................................................... 1-2
1.2.1 Cooling Source .............................................................................................................................. 1-2
1.2.2 Feedback ....................................................................................................................................... 1-3
1.2.3 Control Equation ............................................................................................................................ 1-3
1.2.4 Heating .......................................................................................................................................... 1-3
1.3 MODEL
340
FEATURES................................................................................................................... 1-3
1.3.1 Configurable Inputs........................................................................................................................ 1-3
1.3.2 Input
Isolation................................................................................................................................. 1-4
1.3.3 Input
Reading Capability................................................................................................................ 1-4
1.3.4 Temperature
Response
Curves and CalCurves™......................................................................... 1-5
1.3.5 SoftCal™........................................................................................................................................ 1-5
1.3.6 Configurable Heater Output ........................................................................................................... 1-5
1.3.7 Heater
Output Protection ............................................................................................................... 1-5
1.3.8 Second
Control Loop ..................................................................................................................... 1-5
1.3.9 AutoTune ....................................................................................................................................... 1-5
1.3.10 Setpoint
Ramping and Zones......................................................................................................... 1-5
1.3.11 Internal Programming .................................................................................................................... 1-6
1.3.12
Math............................................................................................................................................... 1-6
1.3.13 Alarms,
Analog
Outputs, and Digital I/O ........................................................................................ 1-6
1.3.14 Memory Card ................................................................................................................................. 1-6
1.3.15 Computer Interface ........................................................................................................................ 1-6
2 COOLING
SYSTEM DESIGN................................................................................................................................. 2-1
2.0 General.............................................................................................................................................. 2-1
2.1 Temperature
Sensor Selection .......................................................................................................... 2-1
2.1.1 Temperature Range....................................................................................................................... 2-1
2.1.2 Sensor
Sensitivity .......................................................................................................................... 2-1
2.1.3 Environmental Conditions .............................................................................................................. 2-2
2.1.4 Measurement Accuracy ................................................................................................................. 2-2
2.1.5 Sensor Package............................................................................................................................. 2-2
2.2 Calibrated Sensors ............................................................................................................................ 2-2
2.2.1 Traditional
Calibration .................................................................................................................... 2-2
2.2.2 SoftCal™........................................................................................................................................ 2-3
2.2.3 Standard Curves ............................................................................................................................ 2-4
2.2.4 CalCurve™ .................................................................................................................................... 2-4
2.3 SENSOR
INSTALLATION................................................................................................................. 2-4
2.3.1 Mounting
Materials......................................................................................................................... 2-4
2.3.2 Sensor Location ............................................................................................................................. 2-4
2.3.3 Thermal
Conductivity ..................................................................................................................... 2-5
2.3.4 Contact Area .................................................................................................................................. 2-5
2.3.5 Contact Pressure ........................................................................................................................... 2-5
2.3.6 Lead Wire....................................................................................................................................... 2-6
2.3.7 Lead
Soldering............................................................................................................................... 2-6
2.3.8 Heat
Sinking Leads........................................................................................................................ 2-6
2.3.9 Thermal
Radiation.......................................................................................................................... 2-6
2.4 HEATER
SELECTION
AND INSTALLATION.................................................................................... 2-6
2.4.1 Heater
Resistance and Power ....................................................................................................... 2-6
2.4.2 Heater Location.............................................................................................................................. 2-7
2.4.3 Heater Types ................................................................................................................................. 2-7
2.4.4 Heater Wiring ................................................................................................................................. 2-7
2.5 CONSIDERATIONS
FOR
GOOD CONTROL ................................................................................... 2-7
2.5.1 Thermal
Conductivity ..................................................................................................................... 2-7
2.5.2 Thermal Lag................................................................................................................................... 2-8
2.5.3 Two-Sensor Approach ................................................................................................................... 2-8
2.5.4 Thermal Mass ................................................................................................................................ 2-8
2.5.5 System
Nonlinearity ....................................................................................................................... 2-8
2.6 PID
CONTROL .................................................................................................................................. 2-9
2.6.1 Proportional (P).............................................................................................................................. 2-9