Length measuring instrument

A length measuring instrument, comprising:

• a hollow profile section extending in a longitudinal direction;
• an end piece fixed on said hollow profile section for closure of said hollow profile section on an end of said hollow profile section, wherein said end piece comprises a compressed air connection that delivers compressed air into an interior of said hollow profile section;
• a scale disposed inside said hollow profile section, wherein said scale comprises a measurement graduation which for position measurement can be scanned by a scanning unit that is movable in said longitudinal direction relative to said hollow profile section;
• and
• a sealing element on said end piece for sealing off said hollow profile section on said end of said hollow profile section, wherein said sealing element has a cross-section that is at least extensively equivalent to an inside diameter of said hollow profile section and said sealing element rests sealingly so that a circumferential surface of said sealing element is on an inner face of said hollow profile section.

A length measuring system, comprising:

• a scanning unit;
• and
• a length measuring instrument comprising:
• a hollow profile section extending in a longitudinal direction;
• an end piece fixed on said hollow profile section for closure of said hollow profile section on an end of said hollow profile section;
• a scale disposed inside said hollow profile section, wherein said scale comprises a measurement graduation that is scanned by said scanning unit, which is movable in said longitudinal direction relative to said hollow profile section;
• and
• a sealing element on said end piece for sealing off said hollow profile section on said end of said hollow profile section, wherein said sealing element has a cross-section that is at least extensively equivalent to an inside diameter of said hollow profile section and said sealing element rests sealingly so that a circumferential surface of said sealing element is on an inner face of said hollow profile section, wherein said sealing element is attached to said end piece in such a way that said sealing element is displaceable relative to said end piece transversely to said longitudinal direction.

A length measuring system, comprising:

• a scanning unit;
• and
• a length measuring instrument comprising:
• a hollow profile section extending in a longitudinal direction;
• an end piece fixed on said hollow profile section for closure of said hollow profile section on an end of said hollow profile section, wherein said end piece comprises a compressed air connection that delivers compressed air into an interior of said hollow profile section;
• a scale disposed inside said hollow profile section, wherein said scale comprises a measurement graduation that is scanned by said scanning unit, which is movable in said longitudinal direction relative to said hollow profile section;
• and
• a sealing element on said end piece for sealing off said hollow profile section on said end of said hollow profile section, wherein said sealing element has a cross-section that is at least extensively equivalent to an inside diameter of said hollow profile section and said sealing element rests sealingly so that a circumferential surface of said sealing element is on an inner face of said hollow profile section.