Lakeshore 325, Руководство пользователя, Страница: 7 / 166

Lake Shore Model 325 Temperature Controller User’s Manual
Table of Contents i
TABLE OF CONTENTS
Chapter/Section Title Page
1 INTRODUCTION .................................................................................................................................................... 1-1
1.0 PRODUCT DESCRIPTION ............................................................................................................... 1-1
1.1 SENSOR SELECTION ...................................................................................................................... 1-4
1.2 SPECIFICATIONS ............................................................................................................................. 1-6
1.3 SAFETY SUMMARY ......................................................................................................................... 1-8
1.4 SAFETY SYMBOLS .......................................................................................................................... 1-9
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 .............................................................................................................. 2-1
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™........................................................................................................................................ 2-2
2.2.3 Standard Curves ............................................................................................................................ 2-3
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 ..................................................................................................................... 2-4
2.3.4 Contact Area .................................................................................................................................. 2-4
2.3.5 Contact Pressure ........................................................................................................................... 2-5
2.3.6 Lead Wire....................................................................................................................................... 2-5
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 ................................................................................................................................... 2-7
2.5.3 Two-Sensor Approach ................................................................................................................... 2-7
2.5.4 Thermal Mass ................................................................................................................................ 2-8
2.5.5 System Nonlinearity ....................................................................................................................... 2-8
2.6 PID CONTROL .................................................................................................................................. 2-8
2.6.1 Proportional (P) .............................................................................................................................. 2-8
2.6.2 Integral (I)....................................................................................................................................... 2-9
2.6.3 Derivative (D) ................................................................................................................................. 2-9
2.6.4 Manual Heater Power (MHP) Output ............................................................................................. 2-9
2.7 MANUAL TUNING ........................................................................................................................... 2-11
2.7.1 Setting Heater Range .................................................................................................................. 2-11
2.7.2 Tuning Proportional ...................................................................................................................... 2-11
2.7.3 Tuning Integral ............................................................................................................................. 2-12
2.7.4 Tuning Derivative ......................................................................................................................... 2-12
2.8 AUTOTUNING ................................................................................................................................. 2-12
2.9 ZONE TUNING ................................................................................................................................ 2-13