PNM Non-Magnetic Chip Resistors Vishay / Thin Film PNM series Non-Magnetic Chip Resistors eliminate materials that would disturb magnetic fields applications, such as MRI magnetic resonance imaging machines. The PNM Series resistors contain non-magnetic materials that eliminate the effects of stray magnetic fields on circuit performance, resulting in simplified shielding requirements and improved sound quality in audio applications. Other features of the PNM series include moisture resistance, high purity alumina substrate availability, non-standard values availability, very low noise and voltage coefficient (<,-30dB), non-inductiveness, 100% visual inspection per MIL-PRF-55342, laser-trimmed tolerances to ±0.1%, wraparound resistance less than 10mΩ, and more.