The Keysight 40653B is an encapsulated sensor (10 k ohm at 25 degrees C) in an aluminum, thermally conductive housing for easy surface mounting (screw-mounted). The exterior is A1 Housing less than 1 x 1 x 0.5 inches with a mounting hole. The thermistor is electrically insulated from the housing in an epoxy capsule. Its fast reponse gives real-time temperature measurements!
The Keysight 40653B is compatible with the Keysight 3458A multimeter. It can also be used with the 34420A, but doing so requires the probe to be rewired onto the Keysight 34104A Low Thermal Input Connector. The 40653B can also be used with the Keysight 34401A, however, an external program is required to convert the resistance measurements to temperature.