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):                                                           
                                                                                      
                                              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 Limited               
    different from 3):                        Securities Services Nominees Limited    
                                              State Street Bank & Trust Boston        
                                              State Street Nominees Limited           
                                              Vidacos Nominees Limited                
                                                                                      
    5. Date of transaction and date on which  22nd February 2017                      
    the threshold is crossed or reached:                                              
                                                                                      
                                              24th February 2017                      
    6. Date on which issuer notified:                                                 
                                                                                      
                                              Above the threshold of 13%              
    7. Threshold(s) that is/are crossed or                                            
    reached:                                                                          
                                                                                      

       

    8: Notified Details                                                                                                    
                                                                                                                           
    A: Voting rights attached to shares                                                                                    
                                                                                                                           
    Class/type   Situation previous  Resulting situation after the triggering transaction                                  
    of shares    to 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 7,001,976 7,001,976 37,418 37,418 7,501,993 0.065%                         13.091%                        

       

    B: Qualifying Financial Instruments                                            
                                                                                   
    Resulting situation after the triggering transaction                           
                                                                                   
    Type of         Expiration date Exercise/       No. of voting   Percentage of  
    financial                       conversion      rights that may voting rights  
    instrument                      period          be acquired if                 
                                                    the instrument                 
                                                    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 voting   Percentage of     
    financial    Price     date       conversion  rights          voting rights     
    instrument                        period      instrument                        
                                                  refers to                         
                                                                                    
                                                                  Nominal     Delta 
                                                                                    

       

    Total (A+B+C)                                                                
                                                                                 
    Number of voting rights                Percentage of voting rights           
                                                                                 
    7,539,411                              13.156%                               

       

    9. Chain of controlled undertakings through which the voting rights and /or  
    the financial instruments are effectively held, if applicable:               
                                                                                 
    Threadneedle Asset Management Limited (13.156%)                              
                                                                                 
    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, Oxford           
                                           Instruments plc                       
                                                                                 
    15. Contact telephone name:            01865 393324