OHAUS CKW3R, Service Manual

CHAPTER 1  INTRODUCTION 

1.3  TOOLS AND TEST EQUIPMENT REQUIRED 

1.  Common hand tools 

2.  Standard electronics tool kit 

3.  Digital Voltmeter (DVM) capable of reading from 1 mv to 50 V dc.) 

4.  Megohmetter (50 Volt dc maximum test voltage) 

5.  Desk magnifier on a stand 

6.  Ohaus Indicator: CKW-55, or equivalent commercial indicator 

7.  A calibrated Torque Wrench N.m. – Ft/Lbs 

1.4  TEST MASSES REQUIRED 

The masses required to test the Ohaus CKW Base when connected to an Indicator must meet 
the requirements of ASTM Class 4 or OIML F2.  Mass values 3kg to 30kg,depending on the 
Base model.  The full scale rated capacity of the Base should be used for Span calibration. 

1.5 SERVICE 

STRATEGY 

The Load Cells used in Ohaus Bases are non-repairable.  The repair method for the Base is 
direct replacement of Load Cells with connecting cable and hardware. 

Each base contains the following basic replaceable assemblies: Platform, Load Cell with 
Connecting Cable, and Down Stop and mounting hardware.  There is an exploded view drawing 
of the Base and associated parts list in Chapter 5.  This service manual contains sufficient 
information to isolate the problem, replace the component, test and restore the Base to its 
original factory specifications. 

1.6  PHYSICAL DESCRIPTION:  MODEL CKW BASES 

Construction 

Platform – Fabricated stainless steel 
Scale Base – Formed and welded base, 304 stainless steel 
Load Cell – Stainless steel  

Overloading 

Corner Loading – 100% of full capacity 
Safe Overload – 150% of full capacity  
Ultimate Overload – 300% of full capacity 

Operating Environment  Designed to meet OIML 3000e and NTEP 5000d requirements 

to operate at a temperature range from –10°C to 40°C /  
14°F to 104°F, 0 to 90% relative, non-condensing humidity 

Ohaus Corporation  www.ohaus.com 

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CKW Base Series Service Manual