In this paper, we discuss about fiber optical sensors, its working principle and a standard test method of evaluating the measurement performance of distributed sensors such as Brillouin scattering based fiber optic sensors (FOSs) and other sensors for monitoring strain is proposed. Strain and temperature measurements are main concern for the performance and condition assessment of different concrete structures. PPP-BOTDA (Pulse-PrePump Brillouin Optical Time Domain Analysis) and the possibility of access with 10cm spatial resolution was illustrated. The system has been applied in various fields using this 10cm spatial resolution and ±25 μe strain measuring precision. This paper reports the result of the theoretical study for the optimal spatial resolution, and the PPP-BOTDA measuring system to realize the theoretical study.