OHAUS Defender D15HR, Service Manual

TABLE OF CONTENTS 

CHAPTER 1  INTRODUCTION

Page No.

1.1 Introduction ................................................................................................................1-1 
1.2  

Service Facilities........................................................................................................1-1 

1.3 

Tools and Test Equipment Required .........................................................................1-2 

1.4  

Test Masses Required...............................................................................................1-2 

1.5 Service 

Strategy ........................................................................................................1-2 

1.6 

Physical Description: Defender H-Q-W Bases ..........................................................1-2 

1.7  

Specifications.............................................................................................................1-3 

1.8 

How Load Cells Operate............................................................................................1-6 

 
CHAPTER 2  TROUBLESHOOTING 

2.1  

Troubleshooting .........................................................................................................2-1 

2.1.1  Checking Load Cells for Trouble ........................................................................2-1 

 
CHAPTER 3  MAINTENANCE AND REPAIR PROCEDURES 

3.1  

Preventive Maintenance ............................................................................................3-1 

3.1.1 Preventive 

Maintenance 

Checklist .....................................................................3-1 

3.2  

Replacing the Load Cell.............................................................................................3-1 

3.3  

Overload Stop Adjustments .......................................................................................3-2 

CHAPTER 4  TESTING 

4.1. Testing .......................................................................................................................4-1 
4.2 

Load Cell Resistance Checks....................................................................................4-1 

4.3 

Calibration with an External Indicator ........................................................................4-1 

4.4. Consistency 

Check ....................................................................................................4-2 

4.5 Performance 

Tests ....................................................................................................4-2 

4.5.1  Off Center Load (Shift) Test ...............................................................................4-3 
4.5.2  Adjusting Off Center Load ..................................................................................4-4 
4.5.3  Full Load Test.....................................................................................................4-5 

 
CHAPTER 5  DRAWINGS AND PARTS LISTS 

5-1   Defender H-Q-W Bases.............................................................................................5-2 

APPENDIX A:  GLOSSARY 

A-1   Glossary.................................................................................................................... A-1 

LIST OF TABLES 

1-1  

Specifications for Defender Rectangular Bases (Regular)....................................1-3 

1-2  

Specifications for Defender Rectangular Bases (Large) .......................................1-3 

1-3  

Specifications for Defender Square Bases (Regular)............................................1-4 

1-4  

Specifications for Defender Square Bases (Large) ...............................................1-4 

1-5  

Specifications for Defender Square Washdown Bases (Regular).........................1-5 

1-6  

Specifications for Defender Square Washdown Bases (Large) ............................1-5 

3-2. 

Overload Gap Settings For Defender H-Q-W Bases.............................................3-3 

4-1 

Load Cell Resistance Readings ............................................................................4-1 

4-2 

Load Cell Output Readings ...................................................................................4-3 

5-1  

Defender H-Q-W Bases: Housing & Internal Parts ...............................................5-3 

(continued next page) 

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Defender™ H-Q-W Series Service Manual