TABLE OF CONTENTS
Ohaus Corporation www.ohaus.com i Navigator Series Service Manual
Page No.
1 GETTING STARTED 1
1.1 INTRODUCTION 1
1.2 SERVICE FACILITIES 1
1.3 TOOLS AND TEST EQUIPMENT REQUIRED 2
1.4 SPECIFICATIONS 2
1.5 CAPACITY AND READABILITY 5
1.6 SCALE OPERATION 10
1.6.1 Overview of the Controls 10
1.6.2 Overview of the Display Indicators 12
1.6.3 Power On 12
1.6.4 Power Off 13
1.6.5 Menu Setup 13
1.7 LEGAL FOR TRADE (LFT) 13
1.8 MENU STRUCTURE 14
1.8.1 User Menu 14
1.8.2 Service Menu 14
2 DIAGNOSTIC GUIDE 16
2.1 TROUBLESHOOTING 16
2.1.1 General procedures for Troubleshooting 16
2.2 DIAGNOSTIC GUIDE 16
3 MAINTENANCE PROCEDURES 19
3.1 PREVENTIVE MAINTENANCE 19
3.2 OPENING THE SCALE 19
3.3 REPLACING THE LOAD CELL 21
3.4 REPLACING THE PRINTED CIRCUIT BOARD AND DISPLAY 23
3.5 REPLACING THE FUNCTION LABEL 23
3.6 DOWN-STOP ADJUSTMENT 23
4 TESTING 25
4.1 TEST MASSES REQUIRED 25
4.2 OPERATIONAL TEST 26
4.3 SEGMENT DISPLAY TEST 26
4.4 LOAD CELL TEST USING RAMP 26
4.5 PERFORMANCE TESTS 27
4.5.1 Precision Test 27
4.5.2 Repeatability Test 28
4.5.3 Linearity Test 30
4.5.4 Off-Center Load Test 31
4.5.5 Adjusting Off Center Load 31
5 PARTS LISTS & DIAGRAMS 33
5.1 HOUSING & INTERNAL PARTS 34
APPENDIX A. STANDARD CALIBRATION 36
A.1 SPAN CALIBRATION 36
A.2 LINEARITY CALIBRATION 37
APPENDIX B. SERVICE MENU 38
B.1 ENTERING THE SERVICE MENU 38
B.2 RAMP 38
B.3 LINEAR CALIBRATION 38