When comparing a Wheatstone bridge detector and a catalytic bead detector (often called a pellistor), it is essential to clarify their fundamental relationship:
they are not competing technologies, but rather complementary components of the exact same industrial gas detection system.
A catalytic bead sensor CANNOT function without a Wheatstone bridge circuit, and in the context of gas detection, the Wheatstone bridge requires the beads to convert a chemical reaction into a readable electrical signal. (Source: Gemini+)
The differences, individual roles, and interplay between the two are outlined below.