| 摘要 |
A frequency characteristic measuring apparatus (10) is disposed close to a cooling medium piping (70) end portion on the outdoor unit (50) side, said cooling medium piping connecting the outdoor unit (50) and an indoor unit (60) to each other in an air-conditioner, and the frequency characteristic measuring apparatus measures the frequency characteristics of the cooling medium piping (70). A filter (30) is attached at a position further toward the outdoor unit (50) side than the position where the terminal (11) of the frequency characteristic measuring apparatus (10) is connected, such that the filter wraps the cooling medium piping (70). A piping length calculating apparatus (20) is connected to the frequency characteristic measuring apparatus (10) via an interface cable (40), and acquires, via the interface cable (40), the frequency characteristics that have been measured by means of the frequency characteristic measuring apparatus (10). The piping length calculating apparatus (20) extracts a minimum antiresonant frequency from the thus acquired frequency characteristics, and calculates the length of the cooling medium piping (70) on the basis of the minimum antiresonant frequency thus extracted. |
