| 摘要 |
<p>An optical probe for use in measuring characteristics of polymers in extruders includes a hemispheric lens fitting against a hemispherically contoured wall inside the fitting. A hollow sleeve is threaded into the fitting to hold the lens in place against the contoured wall. The materials for the lens and fitting are selected to have similar thermal expansion coefficients, such as sapphire lenses and titanium fittings so that in the heat and pressure of the extruder, the stresses on the lens do not lead to its failure.</p> |
