Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the emissivity of wire-grid polarizers for astronomical observations
  at mm-wavelengths   We have measured, using a custom setup, the emissivity of metallic
wire-grids, suitable for polarimeters and interferometers at mm and far
infrared wavelengths. We find that the effective emissivity of these devices is
of the order of a few %, depending on fabrication technology and aging. We
discuss their use in astronomical instruments, with special attention to Martin
Puplett Interferometers in low-background applications, like astronomical
observations of the Cosmic Microwave Background.

33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
8
The categories of this paper are: hep-ex
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
0
The categories of this paper are: hep-ph
25
The categories of this paper are: patt-sol
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
28
The categories of this paper are: alg-geom
14
The categories of this paper are: math-ph
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys