The present document details the architecture, implementation and calibration of a quad-band channel sounder operating in the sub-6 GHz (center frequency of 6.75 GHz), mmWave (center frequency of 74.25 GHz), sub-THz (center frequency of 186.75 GHz) and optical (peak wavelength of 940 nm) domains. This channel sounder is composed of two independent sounders – one for the optical band and the other for the sub- 6 GHz, mmWave and sub-THz bands – that are assembled in a single movable unit that can easily be deployed in industrial environments for multi-band channel measurements. Such measurements are envisioned in various setups that are here presented and will be later used to validate and calibrate the ray-tracing channel model developed in a previous report from point cloud data acquired with 3D laser measurements.