OHAUS EC Series, Service Manual

i

TABLE OF CONTENTS

CHAPTER 1 INTRODUCTION

                                                                                                                   Page

1.

Introduction ...................................................................................................... 1-1

1.1

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

1.2

Tools and Equipment .......................................................................................... 1-2
1.2.1 Standard Tools and Test Equipment ............................................................ 1-2
1.2.2 Special Tools........................................................................................... 1-2

1.3

Calibration Masses Required ................................................................................ 1-2

1.4

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

CHAPTER 2 DIAGNOSIS

2.

Diagnosis

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

2.1

Scale Setup and Examination ............................................................................... 2-1

2.2

Preliminary Checks ............................................................................................. 2-1

2.3

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

2.4

EC Series Scales Error Code Table.......................................................................... 2-5

CHAPTER 3 SCALE TESTING AND CALIBRATION

3.

Testing and Calibration ........................................................................................ 3-1

3.1

Testing the AC Adapter ......................................................................................... 3-1

3.2

Testing the Membrane Switch ............................................................................... 3-1

3.3

Testing the Load Cell Assembly ............................................................................. 3-2
3.3.1 Resistance Test ........................................................................................ 3-2
3.3.2 Excitation and Output Voltage Test ............................................................. 3-2

3.4

Testing the Main PC Board ................................................................................... 3-4
3.4.1 Main PC Board Voltage Measurements ........................................................ 3-4
3.4.2 Simulator Testing ..................................................................................... 3-5

3.5

Testing the Battery ............................................................................................... 3-6
3.5.1 Precautions for Battery Handling ................................................................ 3-6
3.5.2 Battery Tests ............................................................................................ 3-6

3.6

Performance Tests ............................................................................................... 3-8
3.6.1 Segment Display Test ............................................................................... 3-8
3.6.2 Repeatability Test ..................................................................................... 3-8
3.6.3 Off-Center Load Test ............................................................................... 3-10
3.6.4 Linearity Test ......................................................................................... 3-11

3.7

Specifications ................................................................................................... 3-13

3.8

Calibration .................................................................................................... 3-14
3.8.1 Calibration Points .................................................................................. 3-14
3.8.2 Span Calibration .................................................................................... 3-14

3.9

Scale Settings .................................................................................................. 3-15