Detector or Detector Shoe
Scanning shoe carrying one or more transducers, used to protect transducers from mechanical damage.
Source: API RP 5A5, Field Inspection of New Casing, Tubing, and Plain-end Drill Pipe, Reaffirmed August 2010. Global Standards
Detector is the sensing element which measures the gas concentration.
Source: IMO MSC.1/Circ.1370, Guidelines for the design, construction and testing of fixed hydrocarbon gas detection systems, 22 June 2010, International Maritime Organization. Regulatory Guidance