Plumb Site is a proprietary improvement, and a trademark under that spelling, for a spirit level with a viewing mirror to make it easier to use when setting verticals.
A plumb sight is a mirror inside a spirit level that allows the user to view the plumb vial from the front, as well as from the traditional side view, when performing a vertical leveling operation. The user no longer has to squeeze against a wall to see the bubble from the side, but can stand in front of the level and see its reflected image.
Although the use of this sight may be novel for levels, the idea of using a mirror to sight a spirit level bubble from a more convenient position has long been used with surveyor's telescopic dumpy levels.
As well as improving ease of use, a plumb sight may also reduce parallax errors. By using a sight that always views the bubble from the ideal location, risk of reading errors is reduced.
Plumb Site was invented in 1997, and is a feature across Kapro's range of spirit levels.
Famous quotes containing the words plumb and/or site:
“And now the winter sea:
Within her hollow rind
What sleek facility
Of sea-conceited scop
To plumb the nether mind!”
—Allen Tate (1899–1979)
“It is not menstrual blood per se which disturbs the imagination—unstanchable as that red flood may be—but rather the albumen in the blood, the uterine shreds, placental jellyfish of the female sea. This is the chthonian matrix from which we rose. We have an evolutionary revulsion from slime, our site of biologic origins. Every month, it is woman’s fate to face the abyss of time and being, the abyss which is herself.”
—Camille Paglia (b. 1947)