When.com Web Search

Search results

  1. Results From The WOW.Com Content Network
  2. List of reagent testing color charts - Wikipedia

    en.wikipedia.org/wiki/List_of_reagent_testing...

    It is advised to check the references for photos of reaction results. [1] Reagent testers might show the colour of the desired substance while not showing a different colour for a more dangerous additive. [2]

  3. Variations in traffic light operation - Wikipedia

    en.wikipedia.org/wiki/Variations_in_traffic...

    Variations on the protected/permissive traffic signals in the United States; (1) is the "classic" doghouse five-light signal introduced in 1971; (2) and (3) incorporate flashing yellow arrows. In the US, a flashing yellow arrow is a signal phasing configuration for permissive left turns.

  4. Emergency vehicle lighting - Wikipedia

    en.wikipedia.org/wiki/Emergency_vehicle_lighting

    The three emergency lights used in Romania are red, blue and amber. At a red flashing light, bringing the vehicle to a full stop is compulsory, while for a blue light yielding, slowing down and moving out of the way is compulsory, and an amber light means other traffic vehicles must proceed with caution due to an oversized or slow vehicle.