A sensor system for a refrigerant unit, the sensor system comprising: a plurality of hoseless sensors (22, 24, 26, 28) for sensing system parameters of the refrigerant unit, and a portable electronic device configured to receive the system parameters from the hoseless sensors and to calculate system conditions for the refrigerant based on the system parameters, in which the plurality of hoseless sensors comprises a hoseless first pressure sensor and a hoseless second pressure sensor, and a hoseless first temperature sensor and a hoseless second temperature sensor, and the first and second temperature sensors (26, 28) each comprises a temperature sensor clamp having a clamping portion configured to clamp on a tube of the refrigerant unit, the clamping portion including a sensor element to measure temperature about the tube, wherein: the portable electronic device comprises: a communications interface for wirelessly receiving the system parameters from the hoseless sensors; a memory storing a program application for calculating system conditions; and a processor device configured to receive the sensor parameters via the communications interface, and to execute the program application to calculate the system conditions based on the system parameters, and each temperature sensor clamp further comprises a handle and integrated electronics, and the integrated electronics are incorporated into the handle and in electrical connection with the sensor element. a plurality of hoseless sensors (22, 24, 26, 28) for sensing system parameters of the refrigerant unit, and a portable electronic device configured to receive the system parameters from the hoseless sensors and to calculate system conditions for the refrigerant based on the system parameters, in which the plurality of hoseless sensors comprises a hoseless first pressure sensor and a hoseless second pressure sensor, and a hoseless first temperature sensor and a hoseless second temperature sensor, and the first and second temperature sensors (26, 28) each comprises a temperature sensor clamp having a clamping portion configured to clamp on a tube of the refrigerant unit, the clamping portion including a sensor element to measure temperature about the tube, wherein: the portable electronic device comprises: a communications interface for wirelessly receiving the system parameters from the hoseless sensors; a memory storing a program application for calculating system conditions; and a processor device configured to receive the sensor parameters via the communications interface, and to execute the program application to calculate the system conditions based on the system parameters, and each temperature sensor clamp further comprises a handle and integrated electronics, and the integrated electronics are incorporated into the handle and in electrical connection with the sensor element. the portable electronic device comprises: a communications interface for wirelessly receiving the system parameters from the hoseless sensors; a memory storing a program application for calculating system conditions; and a processor device configured to receive the sensor parameters via the communications interface, and to execute the program application to calculate the system conditions based on the system parameters, and a communications interface for wirelessly receiving the system parameters from the hoseless sensors; a memory storing a program application for calculating system conditions; and a processor device configured to receive the sensor parameters via the communications interface, and to execute the program application to calculate the system conditions based on the system parameters, and each temperature sensor clamp further comprises a handle and integrated electronics, and the integrated electronics are incorporated into the handle and in electrical connection with the sensor element.