1. An apparatus for detecting surface profile of a test object, comprising:
a light source for emitting a light beam;
a beam splitter for dividing the light beam into reference and probing beams, the probing beam being directed to a surface of the test object and being reflected by the surface of the test object back to said beam splitter;
a reflective component for receiving the reference beam from said beam splitter and for reflecting the reference beam back to said beam splitter;
said beam splitter combining the reference beam reflected by said reflective component, and the probing beam reflected by the surface of the test object to result in a heterodyne light beam;
a sensor for receiving the heterodyne light beam from said beam splitter and for converting the heterodyne light beam into a corresponding electrical signal;
a carrier adapted to support the test object thereon and capable of relative movement with respect to said beam splitter in a scanning direction; and
a computing device coupled to said sensor for recording the electrical signal converted by said sensor;
wherein said reflective component is configured so that components of the reference beam that are reflected by said reflected component travel at different optical path lengths to said beam splitter;
wherein said beam splitter combines the components of the reference beam with components of the probing beam reflected by a set of scanned segments of the surface of the test object to result in the heterodyne light beam for the scanned segments;
wherein, when relative movement is generated between said carrier and said beam splitter in the scanning direction, said beam splitter is able to combine the components of the reference beam with components of the probing beam reflected by another set of scanned segments of the surface of the test object to result in another heterodyne light beam;
wherein, said computing device, with reference to a path length gradient associated with the components of the reference beam, and information pertinent to the relative movement between said carrier and said beam splitter in the scanning direction, is operable so as to analyze the recorded electrical signals corresponding to the heterodyne light beams to determine the surface profile of the test object on at least one of the scanned segments.
2. The apparatus as claimed in claim 1, wherein said light source emits a white light beam.
3. The apparatus as claimed in claim 1, further comprising an object lens disposed in the path of the light beam emitted by said light source.
4. The apparatus as claimed in claim 1, wherein said reflective component includes a substrate made from a light transmissible material, said substrate having a flat surface and a stepped surface opposite to said flat surface, one of said flat and stepped surfaces being coated with a reflective layer to result in a reflective surface for said reflective component.
5. The apparatus as claimed in claim 1, further comprising a first object lens disposed between said beam splitter and said reflective component.
6. The apparatus as claimed in claim 5, further comprising a second object lens disposed between said beam splitter and said carrier.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A crust breaking device for metal melts, comprising:
a pneumatic cylinder including:
a cylinder housing,
a piston which is axially displaceable within the cylinder housing, and
a piston rod, which is fastened to the piston and is guided through an opening at one end of the cylinder housing such that, by axial displacement of the piston, the piston rod is movable between a retracted final position and an extended final position,
an electronic control unit,
a valve arrangement, which can be actuated by way of the electronic control unit and is connected via working lines to a front pressure chamber and a rear pressure chamber within the cylinder housing, and
a first metal plate, which is fixed within the cylinder housing at a first position and is configured to define a final extended position of the piston or of the piston rod, and
a second metal plate, which is fixed within the cylinder housing at a second position and is configured to define a final retracted position of the piston or of the piston rod,
wherein the first metal plate and the piston are electrically connected to the control unit, such that contact between the piston and the first metal plate closes a first circuit, which signals to the control unit that the piston or the piston rod has reached the final extended position, and
wherein the second metal plate and the piston are electrically connected to the control unit, such that contact between the piston and the second metal plate closes a second circuit, which signals to the control unit that the piston or the piston rod has reached the final retracted position.
2. The device as claimed in claim 1, further comprising lines that are configured to directly or indirectly electrically connect the first metal plate, the second metal plate, and the piston to the control unit and to transmit signals therewith.
3. The device as claimed in claim 1, further comprising at least one line that is configured to directly electrically connect the cylinder housing to the control unit, the electrical connection of the cylinder housing to the control unit simultaneously establishing the electrical connection of one or both of the piston and the piston rod to the control unit.
4. The device as claimed in claim 1, wherein the first metal plate and the second metal plate are is electrically insulated from the cylinder housing.
5. The device as claimed in claim 1, wherein at least one of the first metal plate and the second metal plate is fastened to a housing cover of the cylinder housing.
6. The device as claimed in claim 1, further comprising a container which contains the metal melt and is electrically connected to the control unit via at least one line, such that contact between the piston rod or a tool fastened to the piston rod and the metal melt closes a circuit, which signals to the control unit that the piston rod or the tool has broken the crust of the metal melt.
7. The device as claimed in claim 1, wherein at least one of the first metal plate and the second metal plate is at least partially inset into a housing cover of the cylinder housing.
8. A crust breaking device for metal melts, comprising:
a pneumatic cylinder including:
a cylinder housing,
a piston which is axially displaceable within the cylinder housing, and
a piston rod, which is fastened to the piston and is guided through an opening at one end of the cylinder housing such that, by axial displacement of the piston, the piston rod is movable between a retracted final position and an extended final position,
an electronic control unit,
a valve arrangement, which can be actuated by way of the electronic control unit and is connected via working lines to a front pressure chamber and a rear pressure chamber within the cylinder housing, and
at least one metal plate, which is fixed within the cylinder housing and is configured to define a final position of the piston or of the piston rod,
wherein the metal plate and the piston are electrically connected to the control unit, such that contact between the piston and the metal plate closes a circuit, which signals to the control unit that the piston or the piston rod has reached the final position, and
further comprising a container which contains the metal melt and is electrically connected to the control unit via at least one line, such that contact between the piston rod or a tool fastened to the piston rod and the metal melt closes a circuit, which signals to the control unit that the piston rod or the tool has broken the crust of the metal melt.