Sub-terahertz (sub-THz) communications is expected to be a key element for future wireless communications enabling extremely high data transmission rate. Its performance can be further emphasized by the use of reconfigurable intelligent surface (RIS), which provides the beamforming possibility of electromagnetic (EM) waves in a desired direction. The channel measurement is a fundamental element in understanding the characteristics of the propagation channel. To emulate a system composed of transmissive RIS (T-RIS) and reflective RIS (R-RIS), an electrically large transmit-array and reflectarray were designed. The paper presents the results of the single directional channel measurement of the sub THz channel composing a concatenation of non reconfigurable T-RIS and R-RIS. The results presented in this paper demonstrate the feasibility and scalability of establishing a sub-THz link by concatenating multiple RIS units for future applications.