69K

69K refers to the temperature of 69 kelvin on the Kelvin scale. The Kelvin scale uses absolute zero as its zero point, and one kelvin is the same size as one degree Celsius. Therefore, 69 K is -204.15 °C, which is -335.47 °F.

In scientific contexts, 69 K lies in the cryogenic range. It is far below room temperature and cold enough to alter many material properties. It is typically achieved with cryogenic cooling systems, such as liquid helium or closed-cycle cryocoolers; liquid nitrogen, which boils at 77 K, is insufficient by itself to reach 69 K without additional cooling stages.

At 69 K, some materials may be in a superconducting state if their critical temperature is above that value. For example, many high-temperature superconductors have Tc above 69 K, so they would be superconducting at this temperature provided other conditions are met.

Uses of 69 K include physics and materials science experiments, cryogenics research, and spectroscopy at low temperatures. Its value is representative of a common operating point in laboratory studies where reduced thermal noise and altered electronic or magnetic properties are of interest.