air fog in a sentence

1. Uses 24v DC and cost about $ AUS70 with transformer, it will form a heavier-than-air fog in quiet conditions.
2. In 1851, an experimental air fog whistle and reed horn was installed at Beavertail Lighthouse at the entrance to Narragansett Bay, Rhode Island.
3. On 1 January 1883, a compressed air fog siren was installed, but the process of preparing it for use in fog was usually taking a long time.
4. It's difficult to find air fog in a sentence.