Where particularly poor background contrast cannot be avoided, a " sighting board " ( usually painted white ) can be placed behind the arm to provide adequate contrast which improves visibility.
2.
Most British road traffic lights are mounted vertically on a black rectangle with a white border ( forming a " sighting board " ) and so dichromats can look for the position of the light within the rectangle top, middle or bottom.
How to say sighting board in Hindi and what is the meaning of sighting board in Hindi? sighting board Hindi meaning, translation, pronunciation, synonyms and example sentences are provided by Hindlish.com.
Mobile