Linear encoder, having ▪ a control and analysis unit having storage unit and calibration functionality, ▪ a mass embodiment having a position code marking made of code elements, ▪ a read head having a sensor unit, wherein read head and mass embodiment are movable in relation to one another, and wherein o the sensor unit has at least one first, trailing detection reference point, and at least one second, leading detection reference point, which are fixed spaced apart from one another by means of a substrate, wherein a detection distance is established in each case between two detection reference points (R1, R2), o at least two code elements (20a-d, 27a-c, 28a-c) are detectable in one step by means of the sensor unit, which means, that a detection with unchanged relative positioning of the read head in relation to the mass embodiment can be performed so that at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the first detection reference point and at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the second detection reference point, ▪ a calibration of the position code marking can be carried out by means of the read head using the at least one detection distance with the aid of the calibration functionality, characterized in that ▪ the substrate is manufactured from a dimensionally-durable and aging-resistant material having a linear coefficient of thermal expansion having an absolute value in the range of 0 to at most 5·10 -6 K -1, ▪ whereby the linear encoder is provided for the high-precision calibration with at least one standard (s), which is defined by the at least one detection distance, having a relative error in the range of at most 5·10 -6. ▪ a control and analysis unit having storage unit and calibration functionality, ▪ a mass embodiment having a position code marking made of code elements, ▪ a read head having a sensor unit, wherein read head and mass embodiment are movable in relation to one another, and wherein o the sensor unit has at least one first, trailing detection reference point, and at least one second, leading detection reference point, which are fixed spaced apart from one another by means of a substrate, wherein a detection distance is established in each case between two detection reference points (R1, R2), o at least two code elements (20a-d, 27a-c, 28a-c) are detectable in one step by means of the sensor unit, which means, that a detection with unchanged relative positioning of the read head in relation to the mass embodiment can be performed so that at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the first detection reference point and at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the second detection reference point, o the sensor unit has at least one first, trailing detection reference point, and at least one second, leading detection reference point, which are fixed spaced apart from one another by means of a substrate, wherein a detection distance is established in each case between two detection reference points (R1, R2), o at least two code elements (20a-d, 27a-c, 28a-c) are detectable in one step by means of the sensor unit, which means, that a detection with unchanged relative positioning of the read head in relation to the mass embodiment can be performed so that at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the first detection reference point and at least one code element (20a-d, 27a-c, 28a-c) is detected in relation to the second detection reference point, ▪ a calibration of the position code marking can be carried out by means of the read head using the at least one detection distance with the aid of the calibration functionality, ▪ the substrate is manufactured from a dimensionally-durable and aging-resistant material having a linear coefficient of thermal expansion having an absolute value in the range of 0 to at most 5·10 -6 K -1, ▪ whereby the linear encoder is provided for the high-precision calibration with at least one standard (s), which is defined by the at least one detection distance, having a relative error in the range of at most 5·10 -6.