The disclosed technology is directed to a handpiece for a surgical system. The handpiece comprises a heater, a first detection circuit configured to measure a voltage and a current supplied to the heater, and a memory. The memory stores detection characteristics representing a correlation between a sensor value of the first detection circuit and the at least one of the voltage value and the current value. The correlation is used for determination of one of the voltage value and the current value is applied to the heater as obtained using a second detection circuit having a higher detection accuracy than the first detection circuit. A control parameter is used to control a temperature of the heater and is determined based on temperature changes of the heater while performing a test control that supplies electric power to the heater to control the temperature of the heater in a predetermined manner.
