What are the two main components of the detector head?

• A. Sensor assembly and transmitter assembly
• B. Power supply and housing
• C. Detector array and readout module
• D. Calibration unit and control module

Answer: (A)

The detector head is built to both sense the gas and report that information. The two main parts that do these jobs are the sensor assembly, which is the actual sensing element (whether electrochemical, infrared, or another sensing technology), and the transmitter assembly, which conditions the sensor signal and sends a readable output to the monitoring system. The other options cover support or broader system components, not the core head itself: power supply/housing are general hardware, a detector array and readout module imply a different type of imaging or multi-sensor setup, and a calibration unit with a control module are separate maintenance and control subsystems. So the sensor plus transmitter pair is the essential combination inside the detector head.