TR-1: Notifications of Major Interests in Shares                                                                                   
                                                                                                                                       
                                                                                                                                       
    1. Identity of the issuer or the underlying                 Oxford Instruments PLC                                                 
    issuer of existing shares to which voting rights                                                                                   
    are attached:                                                                                                                      
                                                                                                                                       
                                                                                                                                       
    2. Reason for notification (yes/no)                                                                                                
                                                                                                                                       
                                                                                                         Yes                           
    An acquisition or disposal of voting rights                                                                                        
                                                                                                                                       
                                                                                                         No                            
    An acquisition or disposal of financial instruments which may result in the                                                        
    acquisition of shares already issued to which voting rights are attached                                                           
                                                                                                                                       
                                                                                                         No                            
    An acquisition or disposal of instruments with similar economic effect to                                                          
    qualifying financial instruments                                                                                                   
                                                                                                                                       
                                                                                                         No                            
    An event changing the breakdown of voting rights                                                                                   
                                                                                                                                       
                                                                                                         No                            
    Other (please specify): Voluntary baseline disclosure in line with the UK                                                          
    implementation of the Amended Transparency Directive                                                                               
                                                                                                                                       
                                                       Ameriprise Financial, Inc. and its group                                        
    3. Full name of person(s) subject to                                                                                               
    notification obligation:                                                                                                           
                                                                                                                                       
                                                       HSBC Global Custody Nominee (UK) Limited                                        
    4. Full name of shareholder(s) (if                 Nortrust Nominees LTD                                                           
    different from 3):                                 Securities Services Nominees Limited                                            
                                                       State Street Bank & Trust Boston                                                
                                                       State Street Nominees Limited                                                   
                                                       Vidacos Nominees Ltd                                                            
                                                                                                                                       
                                                                                                                                       
    5. Date of transaction and date on which           26 January 2017                                                                 
    the threshold is crossed or reached:                                                                                               
                                                                                                                                       
                                                       27 January 2017                                                                 
    6. Date on which issuer notified:                                                                                                  
                                                                                                                                       
                                                       Above the threshold of 11%                                                      
    7. Threshold(s) that is/are crossed or                                                                                             
    reached:                                                                                                                           
                                                                                                                                       
                                                                                                                                       
    8: Notified Details                                                                                                                
                                                                                                                                       
    A: Voting rights attached to shares                                                                                                
                                                                                                                                       
    Class/type of  Situation previous to       Resulting situation after the triggering transaction                                    
    shares         the triggering                                                                                                      
    If possible    transaction                                                                                                         
    use ISIN code                                                                                                                      
                   Number of      Number of    Number     Number of voting Percentage of voting rights                                 
                   shares         voting       of         rights                                                                       
                                  rights       shares                                                                                  
                                                                                                                                       
                                                                                                                                       
                                               Direct     Direct Indirect  Direct                         Indirect                     
                                                                                                                                       
    GB0006650450   5,785,267      5,785,267    31,506     31,506 6,477,061 0.055%                         11.303%                      
                                                                                                                                       
                                                                                                                                       
                                                                                                                                       
    B: Qualifying Financial Instruments                                                                                                
                                                                                                                                       
    Resulting situation after the triggering transaction                                                                               
                                                                                                                                       
    Type of           Expiration        Exercise/           No. of voting rights that may Percentage of voting rights                  
    financial         date              conversion          be acquired if the instrument                                              
    instrument                          period              is exercised/converted.                                                    
                                                                                                                                       
                                                                                                                                       
    C: Financial Instruments with similar economic effect to Qualifying Financial                                                      
    Instruments                                                                                                                        
                                                                                                                                       
    Resulting situation after the triggering transaction                                                                               
                                                                                                                                       
    Type of      Exercise   Expiration         Exercise /     No. of  Percentage of voting rights                                      
    financial    Price      date               conversion     voting                                                                   
    instrument                                 period         rights                                                                   
                                                              instrument                                                                  
                                                              refers                                                                   
                                                              to                                                                       
                                                                                                                                       
                                                                      Nominal                                                    Delta 
                                                                                                                                       
                                                                                                                                       
    Total (A+B+C)                                                                                                                      
                                                                                                                                       
    Number of voting rights                        Percentage of voting rights                                                         
                                                                                                                                       
    6,508,567                                      11.358%                                                                             
                                                                                                                                       
                                                                                                                                       
    9. Chain of controlled undertakings through which the voting rights and /or the                                                    
    financial instruments are effectively held, if applicable:                                                                         
                                                                                                                                       
    Threadneedle Asset Management Limited (11.358%)                                                                                    
                                                                                                                                       
    Threadneedle Asset Management Limited is wholly owned by TC Financing Limited,                                                     
    which is itself wholly owned by Threadneedle Asset Management Holdings Limited,                                                    
    which is itself wholly owned by TAM UK Holdings Limited, which is itself wholly                                                    
    owned by Threadneedle Holdings Limited,  which is itself wholly owned by                                                           
    Threadneedle Asset Management Holdings SARL, which is itself wholly owned by                                                       
    Ameriprise International Holdings GmbH, which is itself wholly owned by                                                            
    Ameriprise Financial, Inc.                                                                                                         
                                                                                                                                       
                                                                                                                                       
    Proxy Voting:                                                                                                                      
                                                                                                                                       
                                                                                                                                       
    10. Name of proxy holder:                      N/A                                                                                 
                                                                                                                                       
                                                                                                                                       
    11. Number of voting rights proxy              N/A                                                                                 
    holder will cease to hold:                                                                                                         
                                                                                                                                       
                                                                                                                                       
    12. Date on which proxy holder will            N/A                                                                                 
    cease to hold voting rights:                                                                                                       
                                                                                                                                       
                                                                                                                                       
    13. Additional information:                    The Shares referred to in section 9 of this form are held in portfolios and         
                                                   funds managed on a discretionary basis by the entities set out in section 9.        
                                                   Please note that the Shares are held through certain nominee companies.             
                                                                                                                                       
                                                                                                                                       
    14 Contact name:                               Susan Johnson-Brett                                                                 
                                                   Company Secretary                                                                   
                                                                                                                                       
                                                                                                                                       
    15. Contact telephone name:                    01865 393 200