Holding(s) in Company

For filings with the FSA include the annex                                     
                                                                               
For filings with issuer exclude the annex                                      

TR-1: NOTIFICATION OF MAJOR INTEREST IN SHARESi                                

1. Identity of the issuer or the underlying       Oxford Instruments plc       
issuer of existing shares to which voting                                      
rights are attached: ii                                                        

2 Reason for the notification (please tick the appropriate box or boxes):      

An acquisition or disposal of voting rights                                    
                                                                               
An acquisition or disposal of qualifying financial instruments which           
may result in the acquisition of shares already issued to which voting         
rights are attached                                                            
                                                                               
An acquisition or disposal of instruments with similar economic effect         
to qualifying financial instruments                                            
                                                                               
An event changing the breakdown of voting rights                               
                                                                               
Other (please                                                                  
specify):                                                                      

3. Full name of person(s) subject to                Schroders plc              
the notification obligation: iii                                               
                                                                               
4. Full name of shareholder(s) (if                                             
different from 3.):iv                                                          
                                                                               
5. Date of the transaction and date                   07.08.12                 
on which the threshold is crossed or                                           
reached: v                                                                     
                                                                               
6. Date on which issuer notified:                     08.08.12                 
                                                                               
7. Threshold(s) that is/are crossed                   Below 5%                 
or reached: vi, vii                                                            

8. Notified details:
A: Voting rights attached to shares viii, ix

Class/type of  Situation previous            Resulting situation after          
shares          to the triggering                 the triggering                
                   transaction                      transaction                 
                                                                                
if possible               Number                  Number          % of voting   
using           Number      of      Number          of             rights x     
the ISIN CODE     of      Voting      of          voting                        
                Shares    Rights    shares        rights                        
                                                                                
                                    Direct   Direct  Indirect   Direct  Indirect
                                               xi       xii                     
                                                                                
GB0006650450   2,897,943 2,833,124 2,847,943 N/A     2,783,124 N/A      4.954%  

B: Qualifying Financial Instruments                                            
                                                                               
Resulting situation after the triggering transaction                           

Type of financial Expiration     Exercise/      Number of voting   % of voting 
   instrument     date xiii  Conversion Period rights that may be    rights    
                                    xiv         acquired if the                
                                                 instrument is                 
                                                   exercised/                  
                                                   converted.                  
                                                                               

C: Financial Instruments with similar economic effect to Qualifying Financial  
Instruments xv, xvi                                                            
                                                                               
Resulting situation after the triggering transaction                           

Type of finan  Exercise Expiration Exercise/  Number of voting    % of voting   
     cial       price   date xvii  Conversion rights instrument  rights xix, xx 
  instrument                         period       refers to                     
                                     xviii                                      
                                                                                
                                                                Nominal   Delta 
                                                                                

Total (A+B+C)                                                                  
                                                                               
        Number of voting rights               Percentage of voting rights      
                                                                               
              2,783,1245                                4.954%                 

9. Chain of controlled undertakings through which the voting rights and/or the 
financial instruments are effectively held, if applicable: xxi                 
                                                                               
Schroder Investment Management Limited - 2,715,874 (4.8342%)                   
                                                                               
Schroder Investment Management North America Limited - 67,000 (0.1192%)        
                                                                               
Schroder & Co Limited - 250 (0.00044%)                                         

Proxy Voting:                                                                  
                                                                               
10. Name of the proxy holder:                                                  
                                                                               
11. Number of voting rights proxy                                              
holder will cease to hold:                                                     
                                                                               
12. Date on which proxy holder will                                            
cease to hold voting rights:                                                   

13. Additional information:             The shares referred to in section 9 are
                                        held in portfolios managed by those    
                                        firms on a discretionary basis for     
                                        clients under investment management    
                                        agreements.                            
                                                                               
14. Contact name:                                 Susan Johnson-Brett          
                                                                               
                                                  (Company Secretary)          
                                                                               
15. Contact telephone number:                        01865 393 324