1. BREWER RECENT IMPROVEMENTS 13th Brewer User Group Meeting Beijing, China 12 – 16 September 2011 Arjan Hoogendoorn Brewer Specialist KIPP & ZONEN

2. TOPICS Where do improvements come from? Zenith window Cables and isolation Photomultiplier Other improvements Recent work

3. WHERE DO IMPROVEMENTS COME FROM ? Improvements come from: Requests by Environment Canada (EC) Suggestions from users Suggestions from within Kipp & Zonen Health, safety and environmental requirements Important modifications to the Brewer operational performance are overseen by EC

4. ZENITH WINDOW Zenith window has been made longer Improves performance of the Brewer at high zenith angles A retrofit kit is available

5. OLD SHORT WINDOWNEW LONG WINDOW

6. CABLES & ISOLATION Power and communication cables are more durable Accessory power cable is replaced by one with a connector Separate cable with connector for the surge suppressor New Brewers are supplied with an optically isolated RS 422 - RS 232 converter for connection to the PC

7. PHOTOMULTIPLIER Electron Tubes was no longer capable of making PMTs that meet the requirements of the Brewer Specially made Hamamatsu PMTs are now used Tube diameter is the same as Electron Tubes PMTs, but the length is different A retrofit kit is available for PMT replacements

8. OTHER IMPROVEMENTS A new quartz diffuser with better transmittance is used in filter wheel 1 The sealing of the instrument cover is improved. The azimuth tracker pillar has been strengthened.