English to Russian Tech/Engineering Engineering: Industrial

ст. ASTM C1549
Вот тут:
7.3 Solar Reflectance Measurement—A surface area of suf-
ficient size to cover the 2.5 cm diameter circular port on top of
the measurement head is required. The flat specimen is placed
on top of the circular port and either held in place by hand or
by a weight that will hold the specimen firmly against the rim
of the port.
понятно, о каком port речь,
а дальше этот термин уже вместе образцом идёт:
Position the measurement head manually against a
surface such as a roof or wall. It is important that the rim of the
specimen port be in contact with the specimen around the
entire circumference of the port. The escape of radiation
between the rim of the specimen port and the specimen will
result in inaccurate solar reflectance values.
вот и вопрос