There are three primary technologies: Infrared (IR), Heated Diode, and Corona Discharge. Infrared sensors are the most durable, lasting up to 10 years, and are highly resistant to 'poisoning' from moisture or oil, making them ideal for high-end professional use. Heated Diode sensors are extremely sensitive to halogenated gases but have a shorter lifespan (approx. 100 hours of use). Corona Discharge is the most economical option but is prone to false alarms in contaminated environments. For B2B buyers, Infrared models offer the best long-term ROI despite higher upfront costs.