FT10-RT433-IS is a wireless transmitter with internal Pt100 sensor. The device consists of a radio transmitter module FT10-RT433, a measurement module FT10-IS and from a whip-antenna. The design and construction of the device ensures high measuring accuracy and stability along with outstanding durability and resistance against adverse environmental conditions. The device includes 433.92 MHz radio transmitter and detachable whip-antenna which enables transmissions even out of closed steel cabinets and other difficult targets.The measuring module recommended calibration period is two years. The calibration agreement is offered as an additional service. The service includes replacement measurement modules delivered automatically when the calibration date is approaching. The replacement modules are changed to the places of the measurement modules that are currently in use. This prevents breaks in measurement cost-effectively. The battery is also changed together with calibration, though it would have power left even for several years to come.