Position measurement device, comprising - a cylindrical object (2; 20; 120; 220; 420; 520) having an annularly circumferential reflection measurement graduation (2.1; 21; 121; 212; 421; 521), which is arranged rotatably about the object longitudinal axis, and - a scanning unit (1; 10; 110; 410a, 410b, 510), which is stationary with respect to the rotatably arranged object (2; 20; 120; 220; 420; 520), for optically scanning the reflection measurement graduation (2.1; 21; 121; 212; 421; 521) having a light source (11; 111; 211; 511), a transmission grating (13; 113; 213; 513) and a detector (112; 212; 512), wherein the beams emitted by the light source (11; 111; '211; 511) pass through the transmission grating (13; 113; 213; 513), are then incident on the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), and from here a back reflection in the direction of the detector (112; 212; 512) takes place, by way of which rotation-dependent position signals are able to be generated, and - that the optically effective normal distance (v) between the detector (112; 212; 512) and the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), in dependence on the radius of the cylindrical object (2; 20; 120; 220; 420; 520) is greater than or smaller than the optically effective normal distance (u) between the transmission grating (13; 113; 213; 513) and the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), and - that the normal distance (ε) between the transmission grating (13; 113; 213; 513) and the detector (112; 212; 312; 512) is ε = 2 • u 2 / R plus a tolerance of +/- 20%, with: ε:= normal distance between transmission grating and detector u:= optically effective normal distance of the transmission grating from the reflection measurement graduation R:= radius of the cylindrical object, wherein R > 0 for an external scan and R < 0 for an internal scan. - a cylindrical object (2; 20; 120; 220; 420; 520) having an annularly circumferential reflection measurement graduation (2.1; 21; 121; 212; 421; 521), which is arranged rotatably about the object longitudinal axis, and - a scanning unit (1; 10; 110; 410a, 410b, 510), which is stationary with respect to the rotatably arranged object (2; 20; 120; 220; 420; 520), for optically scanning the reflection measurement graduation (2.1; 21; 121; 212; 421; 521) having a light source (11; 111; 211; 511), a transmission grating (13; 113; 213; 513) and a detector (112; 212; 512), wherein the beams emitted by the light source (11; 111; '211; 511) pass through the transmission grating (13; 113; 213; 513), are then incident on the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), and from here a back reflection in the direction of the detector (112; 212; 512) takes place, by way of which rotation-dependent position signals are able to be generated, and - that the optically effective normal distance (v) between the detector (112; 212; 512) and the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), in dependence on the radius of the cylindrical object (2; 20; 120; 220; 420; 520) is greater than or smaller than the optically effective normal distance (u) between the transmission grating (13; 113; 213; 513) and the reflection measurement graduation (2.1; 21; 121; 212; 421; 521), and - that the normal distance (ε) between the transmission grating (13; 113; 213; 513) and the detector (112; 212; 312; 512) is ε = 2 • u 2 / R plus a tolerance of +/- 20%, with: ε:= normal distance between transmission grating and detector u:= optically effective normal distance of the transmission grating from the reflection measurement graduation R:= radius of the cylindrical object, wherein R > 0 for an external scan and R < 0 for an internal scan. ε:= normal distance between transmission grating and detector u:= optically effective normal distance of the transmission grating from the reflection measurement graduation R:= radius of the cylindrical object, wherein R > 0 for an external scan and R < 0 for an internal scan.