The development of multilayer insulations is aerospace and cryogenic required to know the emissivity of the metallic films used as reflective layers. This work describes an emissometer that measures the total hemispherical emissivity of metallic films evaporated on polyester substrates. The apparatus works at liquid oxigen temperatures and permits to get emissivities from 90K to room temperatures within a 15% precision. The emissometer construction and operation are described in detail. Results of measurements done on Single Aluminized Mylar are presented.
Bekeris, V I;  Ramos, E D;  Sanchez, D H 
- Nunez Univ. Nacional (Argentina). Faculdad de Ciencias Exactas Y Naturales
- Santa Rosa Univ. Nacional (Argentina). Facultad de Ciencias Exactas Y Naturales
- Comision Nacional de Energia Atomica, San Carlos de Bariloche (Argentina). Centro Atomico Bariloche