Thermal Measurements And Control Of A Lightweight Mirror

Woon-Yin Wong

doi:10.1117/12.937979

3 November 1983 Thermal Measurements And Control Of A Lightweight Mirror

Woon-Yin Wong

Proceedings Volume 0444, Advanced Technology Optical Telescopes II; (1983) https://doi.org/10.1117/12.937979
Event: 1983 Astronomy Conferences, 1983, London, United Kingdom

Abstract

For ground-based large diameter lightweight Pyrex mirrors, internal ventilation is a necessity in order to minimize the thermal distortions. However, the demand on the ventilation system does not appear to be significant. Measurement on a sample blank showed significant effects on the blank's thermal time constant and temperature distribution. Compared with the unventilated case, a mild air flow (17 feet per minute) reduces the thermal time constant from 3 hours to 1 hour. A similar kind of flow (21 feet per minute) reduces the internal temperature difference from 2.4°C to 0.3°C, as well as reduces the temperature difference between the blank and the ambient air from 3.2°C to 0.5°C.

Citation Download Citation

Woon-Yin Wong "Thermal Measurements And Control Of A Lightweight Mirror", Proc. SPIE 0444, Advanced Technology Optical Telescopes II, (3 November 1983); https://doi.org/10.1117/12.937979

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available