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 x 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 Sir Martin Wood the notification obligation: iii Lady Audrey Wood 4. Full name of shareholder(s) (if different from 3.):iv 5. Date of the transaction and date 20th December 2012 on which the threshold is crossed or reached: v 6. Date on which issuer notified: 20th December 2012 7. Threshold(s) that is/are crossed Holding has gone below 6% 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 xi Indirect Direct Indirect xii GB0006650450 3,505,530 3,505,530 3,105,530 3,105,530 5.52% 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 3,105,530 5.52%

9. Chain of controlled undertakings through which the voting rights and/or the financial instruments are effectively held, if applicable: xxi

Lady Audrey Wood 1,769,730 (3.15%) Sir Martin Wood 1,335,800 (2.38%) 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: Oxford Instruments plc - Company Secretary 14. Contact name: Susan Johnson-Brett 15. Contact telephone number: 01865 393 200