AstroSat/UVIT carries two gratings in the FUV channel and a single grating in the NUV channel. These gratings are useful for low resolution, slitless spectroscopy in the far and near UV bands of a variety of cosmic sources such as hot stars, interacting binaries, active galactic nuclei, etc. We present calibration of these gratings using observations of UV standards NGC 40 and HZ 4. We perform wavelength and flux calibration and derive effective areas for different grating orders. We find peak effective areas of \(\sim \)18.7 \(\mathrm{~cm^2}\) at \(2325\ \AA \) for the \(-1\) order of NUV-Grating, \(\sim \)4.5 \(\mathrm{~cm^2}\) at \(1390\,\AA \) for the \(-2\) order of FUV-Grating1, and \(\sim \)4.3 \(\mathrm{~cm^2}\) at \(1500\,\AA \) for the \(-2\) order of FUV-Grating2. The FWHM spectral resolution of the FUV gratings is \(\approx \)14.6 \(\AA \) in the \(-2\) order. The \(-1\) order of NUV grating has an FWHM resolution of \(\approx \)33\(\,\AA \). We find excellent agreement in flux measurements between the FUV/NUV gratings and all broadband filters. We have generated spectral response of the UVIT gratings and broadband filters that can directly be used in the spectral fitting packages such as XSPEC, Sherpa and ISIS, thus allowing spectral analysis of UVIT data either separately or jointly with X-ray data from AstroSat or other missions.

AstroSat/UVIT 在 FUV 通道中携带两个光栅，在 NUV 通道中携带一个光栅。这些光栅可用于各种宇宙源（例如热星、相互作用的双星、活动星系核等）的远紫外波段的低分辨率、无狭缝光谱。我们使用对紫外标准 NGC 40 的观察来校准这些光栅和 HZ 4. 我们执行波长和通量校准并得出不同光栅阶次的有效面积。我们在\(2325\ \AA \)处发现\(\sim \) 18.7  \(\mathrm{~cm^2}\) 的峰值有效面积，对于 NUV-Grating的\(-1\)阶，\( \sim \) 4.5  \(\mathrm{~cm^2}\)在\(1390\,\AA \)为\(-2\) FUV-Grating1 的阶数，以及\(\sim \) 4.3  \(\mathrm{~cm^2}\)在\(1500\,\AA \)对于\(-2\) FUV-Grating2的顺序。FUV 光栅的 FWHM 光谱分辨率在\(-2\)顺序中为\(\approx \) 14.6  \(\AA \)。NUV 光栅的\(-1\)阶的 FWHM 分辨率为\(\approx \) 33 \(\,\AA \). 我们发现 FUV/NUV 光栅和所有宽带滤波器之间的通量测量非常一致。我们已经生成了 UVIT 光栅和宽带滤光片的光谱响应，可直接用于光谱拟合包，如 XSPEC、Sherpa 和 ISIS，从而允许单独或结合来自 AstroSat 或其他的 X 射线数据对 UVIT 数据进行光谱分析。任务。