In the United States surveying system, an "inch" is a unit of length, but it is not significantly different from the standard inch used in everyday measurements. An inch in U.S. surveying is equal to 1/12th of a foot, just like the standard inch. This means that one U.S. survey inch is approximately equal to 0.0833333 feet or about 2.54 centimeters.
The primary distinction in U.S. surveying is the use of the survey foot, which is defined as exactly 12 survey inches. This slight difference in the definition of the foot and inch in U.S. surveying is used for precise land measurements and surveying work, especially when dealing with large areas of land. However, for most everyday purposes, the standard inch and foot are used in the United States and other countries that employ the imperial system.
The "archin" is an obsolete unit of length that was historically used in Russia and other parts of the former Soviet Union. The length of an archin varied by region and over time, but it was typically around 28 inches or approximately 71 centimeters. In some regions, an archin could be slightly shorter or longer.
The archin was used for measuring cloth, textiles, and sometimes land. Like many traditional units of measurement, it has largely been replaced by more standardized systems, such as the metric system, in modern times. While the archin is no longer commonly used for official measurements, it may still be encountered in historical or traditional contexts in Russia and other former Soviet states.