OHAUS SD Series, Service Manual

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TABLE OF CONTENTS
Page No.
CHAPTER 1 GETTING STARTED
1.1 Introduction ................................................................................................................1-1
1.2
Service Facilities........................................................................................................1-1
1.3 Tools and Test Equipment Required .........................................................................1-2
1.4 Specifications.............................................................................................................1-2
1.5 Operation ...................................................................................................................1-3
1.5.1 Power Supply .....................................................................................................1-3
1.5.2 Overview of the Controls ....................................................................................1-3
1.5.3 Basic
Functions ..................................................................................................1-4
1.5.4 Dynamic Weighing .............................................................................................1-4
1.6 Calibration..................................................................................................................1-5
CHAPTER 2 TROUBLESHOOTING
2.1 Introduction ................................................................................................................2-1
2.2 Visual Inspection........................................................................................................2-1
2.3 Diagnostic Guide .......................................................................................................2-2
2.3.1 Diagnosis............................................................................................................2-2
2.4 Checking the Load Cell’s Signal ................................................................................2-4
2.4.1 Output Voltage Test ...........................................................................................2-4
2.4.2 Resistance
Test..................................................................................................2-5
2.4.3 Testing the Printed Circuit Board (PCB).............................................................2-6
CHAPTER 3 MAINTENANCE PROCEDURES
3.1 Preventive Maintenance ............................................................................................3-1
3.1.1 Preventive Maintenance Checklist .....................................................................3-1
3.2 Replacement of Major Components ..........................................................................3-1
3.2.1 Main Printed Circuit Board (PCB) Replacement.................................................3-2
3.2.2 Battery
Replacement ..........................................................................................3-3
3.2.3 Function Label Replacement..............................................................................3-3
CHAPTER 4 TESTING
4.1. Testing .......................................................................................................................4-1
4.2 Power
Test.................................................................................................................4-1
4.3 Performance Tests Using a Scale Base ....................................................................4-1
4.3.1 Overload/Underload Test ...................................................................................4-2
4.4 Performance Tests Using a Load Cell Simulator.......................................................4-3
4.5 Calibration Retention Test .........................................................................................4-3
4.6 Repeatability Test ......................................................................................................4-3
4.7 Off-Center Load Test .................................................................................................4-5
4.8 Linearity Test .............................................................................................................4-6
CHAPTER 5 PARTS LISTS & DIAGRAMS
5-1 SD Series Scale: Small Model...................................................................................5-3
5-2 SD Series Scale: Large Model...................................................................................5-5
Ohaus Corporation www.ohaus.com 1 SD Series Scales Service Manual