TABLE OF CONTENTS
MB23 and MB25 Service Manual
ii
Ohaus Corporation www.ohaus.com
CHAPTER 4 FINAL TESTING
continued
Page No.
4.4.1 Precision Test ...................................................................................................4-2
4.4.2 Repeatability Test .............................................................................................4-3
4.4.3 Linearity Test ....................................................................................................4-4
CHAPTER 5 DRAWINGS AND PARTS LISTS
5-1 MB23 and MB25: Housing & Internal Parts ..............................................................5-2
Appendix A STANDARD CALIBRATION
A.1
Weight Calibration ................................................................................................... A-1
A.2
Temperature Calibration.......................................................................................... A-2
A.3
Service Calibration .................................................................................................. A-3
Appendix B SOFTWARE SERVICE TOOL
B.1
Software service tool location .................................................................................. B-1
LIST OF TABLES
TABLE NO.
TITLE
Page No.
1-1
Specifications ......................................................................................................1-3
1-2
Functions of Display Controls ..............................................................................1-4
2-1
Error Codes .........................................................................................................2-2
2-2
Problem Solver ....................................................................................................2-3
4-1
Types of Performance Tests & Tolerances
....................................................4-1
5-1
MB23 & MB25: Housing & Internal Parts .............................................................5-3
LIST OF ILLUSTRATIONS
FIGURE NO.
TITLE
1-1
MB23 and MB25 Function Labels ........................................................................1-4
1-2
MB23 & MB25 Display Indicators .........................................................................1-4
1-3
AC Power ............................................................................................................1-7
1-4
RS232 DB9-pin setup ..........................................................................................1-8
1-5
Solder Points on PCB ..........................................................................................1-8
3-1
MB25 with Top Open ...........................................................................................3-2
3-2
Housing Chamber ................................................................................................3-2
3-3
Lifting Out Plug in Housing ..................................................................................3-2
3-4
Clear Plastic In-use Cover ...................................................................................3-2
3-5
Three screws in Top Housing ..............................................................................3-2
3-6
Lifting the Housing ...............................................................................................3-3
3-7
Fan, Temperature Sensor, Heater cable connectors on Power PCB ...................3-3
3-8
Cables for Temperature Sensor, Fan, Ground and Heater disconnected .............3-4
3-9
Power PCB Connectors .......................................................................................3-5
3-10
Power PCB ..........................................................................................................3-5
3-11
Load Cell Cover ...................................................................................................3-6
3-12
Main Printed Circuit Board ...................................................................................3-6
3-13
Display LCD on Main PCB ...................................................................................3-6
3-14
Load Cell .............................................................................................................3-7
3-15
Load Cell with Ribbon Cable Attached at Bottom .................................................3-7
3-16
Screws Holding Chamber Top to the Heater Frame Housing ...............................3-8
FIGURE
TITLE
Page No.
3-17
Separating the Chamber Top from the Heater Frame Housing ............................3-8
3-18
Testing Heater Leads’ Resistance .......................................................................3-8
