Three fiber Bragg grating (FBG) sensors systems for hydrogen detection are presented using the classic Pd (palladium) coating technique (500 nm) as the hydrogen sensitive film and titanium (Ti) as the adhesive layer with the etched cladding. These systems are compared and used for disaster environment prevention in hydrogen leakage environment where higher values than the normal are presented which increase the risk of explosion. With these systems, 0.1%–4% of the hydrogen volume concentration range in the volume ratio was detected and monitored experimentally in the test room with the very sensitive and stable value which reached 60 pm/1% H₂. In addition, a fast response time, about 6 s, was obtained with an advanced sensor.