What type of motion detector is used in environments with air turbulence and has no false alarm sources outside?

A microwave motion detector is effective in environments where air turbulence and outside false alarm sources could otherwise cause issues. This is because microwave detectors use electromagnetic waves to detect motion, which can penetrate through obstacles and are less susceptible to environmental changes, such as air movement. They can cover larger areas and are often utilized in settings where traditional detectors may fail due to interference or environmental challenges.

The advantage of microwave technology is that it can discern movement based on the reflection of microwave signals, making it suitable for areas with potential air turbulence, such as near HVAC systems or in warehouses. In contrast, other types of detectors are more affected by environmental disturbances; for example, ultrasonic detectors utilize sound waves and can be more influenced by air currents and temperature changes, leading to potential false alarms.

Therefore, in the context of the question, the microwave motion detector's resistance to false alarms in turbulent conditions and its reliable detection capabilities make it the most suitable choice.