Electronic micrometer for sensing the diameter of a cylindrical body

An electronic profile acquisition micrometer system for sensing the diameter and variations in the diameter of a cylindrical body while the cylindrical body is oriented so that its longitudinal axis is approximately horizontal, the micrometer system comprising:

• a portable freestanding micrometer unit comprising:
• a housing;
• wheels mounted to the housing and adapted for supporting the housing on an upper surface of the cylindrical body while the cylindrical body is oriented so that the longitudinal axis thereof is approximately horizontal and the housing travels on the upper surface of the cylindrical body along a longitudinal length thereof;
• an arm mounted to the housing and projecting outwardly therefrom in a lateral direction approximately perpendicular to the longitudinal axis of the cylindrical body, the arm having graduations along a length thereof;
• first electronic linear measurement means for producing a first output signal, the first electronic linear measurement means being movably mounted to the arm so that the first electronic linear measurement means can be selectively positioned along the length of the arm with the graduations, the first electronic linear measurement means being adapted for contacting a first surface point of the cylindrical body when the first electronic linear measurement means is vertically displaced, the first surface point being laterally spaced apart from the housing and disposed in a cross-sectional plane of the cylindrical body, the first surface point defining a terminal of a horizontal chord lying in the cross-section plane of the cylindrical body;
• and
• second electronic linear measurement means for producing a second output signal, the second electronic linear measurement means being mounted to the housing for contacting a second surface point of the cylindrical body beneath the housing when the second electronic linear measurement means is vertically displaced, the second surface point being disposed in the cross-sectional plane of the cylindrical body and locating the midpoint of the length of the horizontal chord;
• data acquisition means for receiving the first and second output signals from the first and second electronic linear measurement means and storing the output signals as data;
• a computer separate from and outside the housing for receiving the data stored by the data acquisition means and calculating the diameter of the cylindrical body based on the length and height of the horizontal chord ascertained from the first and second output signals of the first and second electronic linear measurement means, the length of the horizontal chord being ascertained by the relative positions in the lateral direction of the first and second surface points sensed by the first and second electronic linear measurement means, the height of the horizontal chord being ascertained by the relative vertical positions of the first and second surface points sensed by the first and second electronic linear measurement means;
• and
• means for connecting the computer to the data acquisition means for transmitting the data.

A method of determining the diameter of a cylindrical body, the method comprising the steps of:

• supporting a housing on a surface of the cylindrical body while the cylindrical body is oriented so that its longitudinal axis is approximately horizontal;
• positioning a first measurement means relative to the housing in a lateral direction approximately perpendicular to the longitudinal axis of the cylindrical body;
• producing a first output signal with the first measurement means by sensing a first surface point of the cylindrical body laterally spaced apart from the housing and disposed in a cross-sectional plane of the cylindrical body, the first surface point defining a terminal of a chord lying in the cross-section plane of the cylindrical body;
• producing a second output signal with a second measurement means by sensing a second surface point of the cylindrical body adjacent the housing and disposed in the cross-sectional plane of the cylindrical body, the second surface point defining a location along the length of the chord;
• and
• determining the diameter of the cylindrical body based on the length and height of the chord ascertained from the first and second output signals.