第一级光谱 meaning in English
primary spectrum
spectrum of first order
Examples
the spectrograph uses a concave diffraction grating that provides a wavelength dispersion of 4. 2a°/mm in the first order. 光谱仪用了一块凹面衍射光栅，第一级光谱的色散度为42埃毫米。
primary spectrum
spectrum of first order