When accurately measuring lengths in bases and polygonometry of all classes, it is extremely important to know about the behavior of the length measure not only over some longer period of time, such as, for example, between two comparisons in laboratories, but also over shorter intervals. For this, as the instructions say , for polygonometry of classes II and III, field comparators should be installed. The device of field comparators can be temporary or permanent. A temporary comparator simply represents a comparison on supports (pillars) of a normal measure, for example, a 24 m wire with a 24 m or 48 m measure (wire) that is used in work. Let us analyze a universal field basis comparator, a slightly different device, proposed by us and arranged with the assistance of N. G. Kell and with the personal participation of L. N. Kell at the geodetic station L. G. I. in Vyshegorod (see article). When accurately measuring lengths in bases and polygonometry of all classes, it is extremely important to know about the behavior of the length measure not only over some longer period of time, such as, for example, between two comparisons in laboratories, but also over shorter intervals. For this, as the instructions say, field comparators must be installed for class II and III polygonometry. The device of field comparators can be temporary or permanent. A temporary comparator simply represents a comparison on supports (pillars) of a normal measure, for example, a 24 m wire with a 24 m or 48 m measure (wire) that is used in work. Let us analyze a universal field basis comparator, a slightly different device, proposed by us and arranged with the assistance of N. G. Kell and with the personal participation of L. N. Kell at the geodetic station L. G. I. in Vyshegorod (see article).
