OHAUS EXPLORER User manual

Ohaus Corporation www.ohaus.com 1 Explorer 5 Semi-Micro Balances
Explorer®Semi-Micro Balances
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 UNIT CAPACITY AND READABILITY 3
1.6 BALANCE OPERATION 4
1.6.1 Overview of the Controls 4
1.6.2 Main Menu and Principal Functions 5
1.6.3 Menu Navigation 5
1.6.4 Changing Settings 6
1.6.5 Functions and Icons 7
1.7 IONISZER 9
1.8 LEGAL FOR TRADE (LFT) 9
1.9 MENU STRUCTURE 10
1.9.1 User Menu 10
1.9.2 Diagnostics Menu 10
1.10 Securing the Menu and Key Lock menu settings 11
2 DIAGNOSTIC GUIDE 12
2.1 TROUBLESHOOTING 12
2.2 SOFTWARE 12
2.3 DIAGNOSTIC GUIDE 12
3 MAINTENANCE / REPAIR PROCEDURES 16
3.1 PREVENTIVE MAINTENANCE 16
3.2 OPENING THE BALANCE 16
3.2.1 Preparation for Opening Explorer® Models 16
3.2.2 Opening the Terminal Module 18
3.2.3 Opening the Base Module with a Draftshield 20
3.3 REPLACING THE LOAD CELL 22
3.4 REPLACING THE PRINTED CIRCUIT BOARD ASSEMBLIES (PCBA) 25
3.4.1 Terminal 25
3.4.2 Base 28
3.5 Replacing the Function Label 30
3.6 Replacing the Touch Panel 31
3.7 Replacing the Feet 31
3.8 Replacing the Ionizer 32
3.9 Replacing the Auto Door Mechanism 33
3.9.1 Replacing the PCBA door sensor 33
3.9.2 Replacing bracket driver assembly 34
3.9.3 Assemble motor driver assembly 35
3.9.4 Replacing motor 35

Page No.
4 TESTING 36
4.1 TEST MASSES REQUIRED 36
4.2 OPERATIONAL TEST 36
4.3 LOAD CELL TEST USING RAMP 36
4.4 PERFORMANCE TESTS 36
4.4.1 Precision Test 37
4.4.2 Repeatability Test (non-approved models) 37
4.4.3 Linearity Test 39
4.4.4 Off-Center Load Test 39
5 PARTS LISTS & DIAGRAMS 41
5.1 TERMINAL SPARE PARTS 41
5.2 BASE SPARE PARTS EXPLOERER 5 DECIMAL 43
5.3 DRAFTSHEILD SPARE PARTS EXPLORER 5 DECIMAL 45
APPENDIX A - USER CALIBRATIONS 47
A.1 SPAN CALIBRATION 47
A.2 LINEARITY CALIBRATION 48
A.3 TOUCH SCREEN CALIBRATION 48
APPENDIX B - DIAGNOSTIC / SERVICE MENU 49
B.1 User Accessible Diagnostics 49
B.2 Service Sub-Menu 50
APPENDIX C –SERVICE TOOL 54
C.1 Balance Commands 54
C.2 RS232 (DB9) Pin Connections 58
C.3 USB Interface 58
APPENDIX D –FIRMWARE UPGRADE VIA USB 60

LIST OF TABLES
TABLE NO. TITLE Page No.
1-1 Specifications ………………………………………………………………………………………………………..2
1-2 Capacity and Readability .................................................................................................................. .........3
1-3 LFT Settings ...............................................................................................................................................9
1-4 Explorer® User Menu ................................................................................................................................10
2-1 Diagnostic Guide .............................................................................................................................……..13
4-1 Calibration Mass Values ..................................................................................................................... ….37
4-2 Repeatability Worksheet ..................................................................................................................... ….39
4-3 Linearity Test –Reference and Load Masses ..................................................................................... …40
4-4 Off Center Load Mass Values ..................................................................................................................41
4-5 Tolerance Table ……………………………………………………………………………………………………42
5-1 Terminal Spare Parts ...............................................................................................................................43
5-2 Base Spare parts Explorer 5 Decimal Models………………………………………………………………….45
5-3 Draft Shield Spare Parts Explorer 5 Decimal Models………………………………………………………….47
B-1 Service Calibration Mass Values ......................................................................................................... …54
C-1 Interface Command List ...........................................................................................................................56

Ohaus Corporation www.ohaus.com 1 Explorer 5 Semi-Micro Balances
1 GETTING STARTED
1.1 INTRODUCTION
This service manual contains the information needed to perform routine maintenance and service
on the Ohaus Explorer® Series balances. Familiarity with the balance’s Instruction Manual is
assumed. The contents of this manual are contained in five chapters:
Chapter 1 - Getting Started
Contains information on service facilities, tools,
specifications, and
the mechanical and electronic functions of the
balance.
Chapter 2 - Troubleshooting
Contains a diagnostic guide and error code table.
Chapter 3 - Maintenance Procedures
Contains preventive maintenance procedures and
disassembly, repair and replacement procedures.
Chapter 4 - Testing
Contains a list of required test masses, an
operational test, segment display test, performance
tests and adjustments.
Chapter 5 - Drawings and Parts Lists
Contains exploded views of Explorer® balances
identifying
all serviceable components.
Appendix A - User Calibrations
Explains user calibration procedures that may need
to be
performed during service.
Appendix B - Service Calibration
Describes the Service Menu and sub-menus, which
allow
authorized service personnel to see Ramp readings
and perform service calibrations.
Appendix C - Software Service Tool Instructions
Used to re-configure the balance after
replacing a Printed Circuit Board or Load-cell.
1.2 SERVICE FACILITIES
To service a balance, the service area should meet the following requirements:
Should be temperature controlled and meet balance specifications for temperature
environmental requirements.
Must be free of vibrations such as fork lift trucks close by, large motors, air currents or drafts
from air conditioning/heating ducts, open windows, people walking by, fans, etc.
Area must be clean and free of excessive dust.
Work surface must be stable and level.
Balance must not be exposed to direct sunlight or radiating heat sources.
Handle all electronic assemblies with appropriate Electro-Static protection.

Ohaus Corporation www.ohaus.com 2 Explorer 5 Semi-Micro Balances
1.3 TOOLS AND TEST EQUIPMENT REQUIRED
Common hand tools are sufficient to disassemble the Explorer® balances.
A PC running Microsoft Windows XP or later.
Explorer® Software Service Tool, PN 83032124
RS232 Cable –Balance to PC PN 80500525
Digital voltmeter (DVM) with an input impedance of at least 10 meg-ohms at 1 volt DC.
Masses as shown in Table 4-1.
1.4 SPECIFICATIONS
Specifications for the Ohaus Explorer® Balances are listed in Table 1-1. When a balance has been
serviced, it must meet the specifications listed in the table. Before servicing the balance, determine
what specifications are not met.
Special Note regarding Approved balances:
The specifications for the approved balances below are only for initial testing. These balances must
be tested according to the requirements of the local Weights and Measures authority. Before
returning the balance to service an approved representative of the local Weights and Measures
authority must certify the balance.
Ambient conditions
Indoor use only
Altitude: Up to 2000 m
Specified Temperature range: 18°C to 23°C
Humidity: maximum relative humidity 15%~80%, the change rate should be less than 10%/hour.
Mains supply voltage fluctuations: up to -15% to +10% of the nominal voltage
Over voltage category II
Pollution degree: 2
Operability is assured at ambient temperatures between 10°C and 30°C
TABLE 1-1 EX 5 Decimal Models.
MODEL
EX125D
EX125DM
EX125
EX125M
EX225D
EX225DM
EX225D/AD
EX225DM/AD
EX225/AD
EX225M/AD
Capacity
52g/120g
120g
120g/220g
120g/220g
220g
Readability d
0.01mg/0.1mg
0.01mg
0.01mg/0.1mg
0.01mg/0.1mg
0.01mg
Repeatability
(std. dev.)
(20g)
0.015mg
0.015mg
0.015mg
0.015mg
0.015mg

Ohaus Corporation www.ohaus.com 3 Explorer 5 Semi-Micro Balances
Repeatability
(std. dev.)
(100g)
0.1mg
0.03mg
0.03mg/0.1mg
0.03mg/0.1mg
0.03mg
Linearity (g)
±0.1mg
±0.1mg
±0.1mg
±0.1mg
±0.1mg
Zero Drift
0.10 mg/°C
Span
Sensitivity
0.80 ppm/°C
Note: MPE - Maximum Permissible Error
MPE
For loads (m) in verified units (e)
Class I
±0.5 e
0≤m≤50,000
±1 e
50,000<m≤200,000
±1.5 e
200,000<m
Maximum errors for balances in usage are twice the acceptable errors for initial verification.
1.5 UNIT CAPACITY AND READABILITY
The capacity and readability of the available units of measure are listed in Table 1-2.
TABLE 1-2 UNIT CAPACITY (Max) AND READABILITY (d)
Units
EX125D
EX125
EX225D;EX225D/AD
EX225/AD
grams
52
/
120
120
120
/
220
220
0.00001
/
0.0001
0.00001
0.00001
/
0.0001
0.0001
dwt
33.43678
/
77.1618
77.1618
77.16180
/
141.4633
141.4633
0.00001
/
0.0001
0.00001
0.00001
/
0.0001
0.0001
ti
3.18445
/
7.3487
7.34874
7.34874
/
13.4727
13.4727
0.000001
/
0.00001
0.000001
0.000001
/
0.00001
0.00001
ozt
1.67617
/
3.8681
3.86809
3.86809
/
7.0915
7.0915
0.0000005
/
0.000005
0.0000005
0.0000005
/
0.000005
0.000005
m
13.86667
/
32.0000
32
32.00000
/
58.6667
58.6667
0.000005
/
0.00005
0.000005
0.000005
/
0.00005
0.00005
oz
1.83425
/
4.2329
4.232875
4.23288
/
7.7603
7.7603
0.0000005
/
0.000005
0.0000005
0.0000005
/
0.000005
0.000005
ct
260.00000
/
600.0000
600
600.00000
/
1100.0000
1100.0000
0.0001
/
0.001
0.0001
0.0001
/
0.001
0.001
GN
802.48220
/
1851.8820
1851.882
1851.88200
/
3395.1170
3395.1170
0.0002
/
0.002
0.0002
0.0002
/
0.002
0.002
msg
11.28394
/
26.0399
26.03985
26.03985
/
47.7397
47.7397
0.000005
/
0.00005
0.000005
0.000005
/
0.00005
0.00005
baht
3.43008
/
7.9156
7.91557
7.91557
/
14.5119
14.5119
0.000001
/
0.00001
0.000001
0.000001
/
0.00001
0.00001
tola
4.45824
/
10.2882
10.28824
10.28824
/
18.8618
18.8618
0.000001
/
0.00001
0.000001
0.000001
/
0.00001
0.00001

Ohaus Corporation www.ohaus.com 4 Explorer 5 Semi-Micro Balances
mg
52000.00000
/
120000.0000
120000
120000.00000
/
220000.0000
220000.0000
0.01
/
0.1
0.01
0.01
/
0.1
0.1
custom(1)
custom(2)
custom(3)
1.6 BALANCE OPERATION
The Explorer®is a very simple to use yet sophisticated balance. Please refer to the Explorer® Instruction
Manual for complete information on the set up and use of the balance.
1.6.1 Overview of the Controls.
This equipment utilizes a touch-sensitive display. Touch areas and Buttons to control the equipment’s functions.
CONTROLS
Touch to access application setup menu
Touch to change
applications
Touch to access
available libraries
Touch for information menu
Instructional Messages
Stability (*), Net (NET),
Gross (G) and/or center of
zero (>0<) indicators
Touch unit indicator to change
weighing unit
Capacity or Status Guides:
Vary by application
Result Fields: Information
varies by application
Application Buttons: Functions
vary by application
Touch icons to perform
specific functions or
access other functions
1.6.2 Main Menu and Principal Functions.

Ohaus Corporation www.ohaus.com 5 Explorer 5 Semi-Micro Balances
Touch Menu to open the menu list.
Touch and drag the Scroll bar to view additional items.
Calibration:
Touch to view calibration options.
User Settings:
Touch to view user preferences.
Balance Setup:
Touch to view balance settings.
Application Modes:
Touch to view application modes.
Weighing Units:
Touch to view weighing units.
GLP and GMP Data:
Insert user data for traceability.
Diagnostics:
Touch to view Diagnostics items.
Communication:
Touch to view COM Device Settings and Print
Settings.
Factory Reset:
Touch to do a Factory reset.
Library:
Touch to delete all Library records.
Lockout:
Touch to access the Lockout menu list.
I/O Settings:
Touch to view remote I/O Settings.
Information:
Touch to view list of topics.
1.6.3 Menu Navigation.
All menu navigation is performed by touching the display. To enter the Menu, touch Menu from
any Application Home screen. The Main menu appears, with buttons for Main, Back and Done.

Ohaus Corporation www.ohaus.com 6 Explorer 5 Semi-Micro Balances
Continue touching the appropriate list item to navigate to the Menu items or touch a button to
change location.
1.6.4 Changing Settings
These Icons are available to setup and operate the Balance. Refer to the Instruction Manual for
more information.
To change a menu setting, navigate to that setting using the following steps:
Enter the Menu
From any Application screen, Touch Menu. The Main Menu List appears on the display.
Select the Sub-Menu
Scroll down to the selected item of the Main. Menu List and touch it. The Sub-Menu appears.
Select the Menu Item
Continue until the desired setting is chosen in the Menu list. Touch the setting to change it. The changed
setting will be displayed as highlighted for 2 seconds to confirm the changed value.
Exit the Menu and Return to the Current Application.
After the setting is confirmed, touch Home to return to the Application.
Note: at any time the Main, Back & Done buttons can be touched to navigate to the desired area of
the menu or return to the current Application.