Dekameter
A dekameter (dam) is a unit of length in the metric system, equal to 10 meters. It sits between a meter and a hectometer in size. Although it is an official part of the metric system, the dekameter is rarely used in everyday life, education, or even science. For example, a small swimming pool might be around 2 dekameters long. The symbol for dekameter is "dam". Since most people prefer using meters or kilometers, the dekameter is more of a theoretical unit used mainly for teaching the structure of the metric system.
Russian Archin
The archin (also spelled arshin) is a traditional Russian unit of length that was widely used before the adoption of the metric system. It is approximately equal to 28 inches or 0.7112 meters.
The archin was commonly used in measuring cloth, land, and building dimensions in Russia and neighboring regions. It roughly corresponds to the length of a forearm from the elbow to the tip of the middle finger, similar to the cubit.
Though obsolete today, the archin remains an important part of Russian historical measurements and appears in older legal and trade documents.
Summary:
1 archin ≈ 28 inches (0.7112 meters)
Used historically in Russia for textiles and land measurement
Based on the length of the forearm
Mostly of historical and cultural interest today
No conversions available for length.