Abstract: This paper presents a comprehensive measurability analysis for grating monochromator wavelength calibration devices based on continuous spectrum light sources and Fourier Transform Spectrometers (FTS). The study identifies and extracts critical parameters such as wavelength indication error, spectral bandwidth, and wavelength repeatability for achieving measurability. The research delves into the metrological design, emphasizing the measurement methodologies for wavelength indication error, the routes for traceability, and the interface dynamics between optics and mechanics. The veracity of the proposed metrological design is tested through a series of experiments. The study adopts a life-cycle approach for the device's measurability design, analyzing from the vantage points of multiple stakeholders and under varied scenarios. The overarching goal of this research is to ensure that all requirements for measurement instruments are meticulously addressed. By sequentially addressing potential pitfalls, this study aims to mitigate management oversights during the project's progression, thereby enhancing the likelihood of success for the measurement device's development.