摘要 |
A capacitance humidity sensor according to the invention has a film core which is in contact with a pair of conductive layers bonded to opposite faces of the core. The core is made of a polyimide having a dielectric constant which varies substantially linearly with humidity and which includes at least one ether linkage in the dianhydride portion thereof. The polyimide may also include at least one ether linkage in the diamine portion thereof and/or at least one fluorine atom in the diamine, dianhydride or both the diamine and dianhydride portions thereof. |