Radar signals can penetrate vapor space containing dust or steam which is problematic for ultrasonic devices.
雷达信号可以穿透包含灰尘或蒸汽的蒸汽空间，这对于超声波装置是有问题的。
2
If oil vapor or other hydrocarbons to system cause problems, or processes can't deal with oil steam can be in the air, line installed oil steam filter.
Compressed air actual if keep steam condition, won't cause system problems, if want to remove all of the water vapor in the compressed air is not only very expensive, and it is unrealistic.