The parallel beam emitted from
the light source of long service life shines onto the
measured object via optical lens. Through receiving lens,
the measured profile forms a projection image of external
profile on high-resolution CCD camera (able to differentiate
0.005% variation in visual field). With extremely high-speed
electronic shutter (0.0001 second), CCD will shoot the
width of this projection (i.e. diameter) and send it to
the computer for analysis and calculation. The advantage
of the imaging measurement is that it can obtain clearly-profiled
size at the same moment and on the same section by extremely
high-speed shooting. With 8 or 10 groups of basic measuring
units distributed on the same plane by an interval of
22.5¡ã or 18¡ã, we can quickly measure the profile size
of an object on the same section. This measurement forms
approximate complete round section of circumscribed hexadecagon
or icosagon. Among the domestic and foreign diameter measuring
instruments, the Model GDC-JB.X.L is the only equipment
that can truly measure the profile size of the screw steel,
rod and wire at the same moment and on the same section.
This invention has been awarded patent in China.
¡ø Relation between Circumscribed
Hexadecagon and Inscribed Circle
Shown on right is a circumscribed
hexadecagon which is formed by measuring the round steel
with 8 groups of parallel beam. It can be seen that it
is approximate to a complete section. The area where two
beams cross is insensitive area (It is insensitive other
than it cannot be measured. Even the most insensitive
point ¡ª11.25o protrusion can be measured, as long as it
is larger than 0.98% of the diameter), where the measuring
error is also very small. On actual production line, the
measured object always has a specific angle of rotation.
As long as the radial rotation of the measured object
is over 5o, the measuring error will be less than 0.3%
of the diameter. Therefore, this measuring method eliminates
the ¡°blind area¡±, while the measuring error for protrusion
defect will not be over 0.98% of the diameter at highest,
generally not over 0.3% of the diameter. With high-speed
measuring method for same moment and same section, we
can obtain data volume of the sectional shape 100 times
more than the rotary measuring method and (2000~6000)
times more than the swing measuring method.
Tianjin EastLoong Opto-electronic Measuring
& Control Technology Co., Ltd. 2004¡ª2005 (C) Copyright 2006 All Rights
Reserved
