Autocollimator to measure straightness
Time：2021-05-07 17:51:35 | 【
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Adjust the autocollimator and the mirror to ensure that the autocollimator can get the reflected image within the full measuring range. Place the reflector at the initial measurement position of the rail, record the current Y component angle value of the autocollimator, and then move the reflector to complete the measurement of the entire rail according to the initially set intercept b. The angle value of the Y component of the autocollimator reflects the height change of the current position of the guide rail relative to the initial starting position, which is specifically expressed as the slope value of each section relative to the initial position.
K=ΔY’/2f’
or
K=Δθy
From this, the height change of the current point relative to the initial reference point can be calculated as
Δh=Kb=Δθyb
ΔY’ Offset of the position of the cross image of the reticle
f’ Autocollimator focal length
Y angle component of Δθy photoelectric autocollimator
Then according to the fitting principles such as least square method or least containment method, the straightness change curve of the entire section of the guide rail can be drawn.
