An active heat-dissipating type of power supply apparatus includes a casing, a first airflow channel, a second airflow channel, plural electronic components, an airflow driving device and a power input device. The system obtains a topological description of the existing telephone loop and identifies a loop equivalent to the existing telephone loop from the topological description of the existing telephone loop. For the purpose of activation, dedicated activation signals are generated by means of the control apparatus and transmitted to the alarm systems. At least one sample chamber with a slidable piston therein defining a sample cavity and a buffer cavity is also provided.