Seal with a blockable rotor for measuring instruments

A seal for measuring instruments, the seal comprising:

• a blockable rotor;
• a transparent body made from plastic and formed with a cylindrical cavity having a blind end and openings, which are formed on lateral sides of the cylindrical cavity, and through which a flexible sealing element passes, and formed with a rectangular cavity, which is installed at the open end, of the cylindrical cavity and extends transversely with respect to the cylindrical cavity, wherein the cylindrical cavity and the rectangular cavity are interconnected, wherein the blockable rotor is housed within the cylindrical cavity so as to be rotatable in one direction with the help of flexible ratchet locks located on the blockable rotor that contact with the longitudinal ribs located on an inner side of the cylindrical cavity, wherein the blockable rotor includes openings configured to be located coaxially with the openings of the cylindrical cavity so as to receive portions of the flexible sealing element, wherein the blockable rotor is divided by a partition into two cavities for winding of the flexible sealing element on the blockable rotor when the blockable rotor is rotated in the one direction, wherein a blocking device is configured to be located in the rectangular cavity and to block the rotation of the blockable rotor in the one direction within the cylindrical cavity, wherein a blocking cross-shaped element is mounted on one end of the blockable rotor and a handle is installed on a front outer wall of the blockable rotor, wherein the blocking device includes a fork-shaped end with two projections and a trapezoidal groove formed between the two projections, wherein the two projections cooperate with the blocking cross-shaped element to block the rotation of the blockable rotor in the one direction, and wherein the blocking device further includes flexible ratchet locks located on lateral walls of the blocking device that engage with rigid ribs located on inner walls of the rectangular cavity when the blocking device is located in the rectangular cavity.