Abstract: An example storage device may include a sealed enclosure that encloses an atmosphere comprising a gas. The sealed enclosure may enclose a storage medium and a read-write head including a thermal flying-height control (TFC) heater and an embedded contact sensor (ECS) including a DC resistance (DCR) sensor. A DC resistance exhibited by the DCR sensor may be indicative of a temperature sensed adjacent the DCR sensor. The storage device may include a controller. The controller may cause a current to be applied to the TFC heater to generate heat, receive a signal from the ECS indicative of the temperature sensed by the DCR sensor, and determine a composition of the atmosphere or a concentration of the gas based on the signal.