IE-45 Subtract / (F)STC / NIC
The IE‑45 provides a powerful function which allows the user to subtract one curve from another. A stored scratch memory curve can be subtracted from the real time display, or one scratch memory curve can be subtracted from another, or from an Average curve. Tap the "Subtract" stylus button to access the subtract control screen. Here you can choose which spectrum you wish to subtract from another. Upon tapping "S1‑S2" the RTA display returns with a "0" center reference and blue RTA bars. You are viewing the one spectrum subtracted from the other. To return to normal RTA, tap the Subtract stylus button and tap "Cancel".
NIC / "Continuous" NIC
The measurement of NIC (Noise Isolation Class) is a staple of transmission loss or noise isolation measurements. The traditional setup requires an "inside" measurement (on the side of the barrier with the noise source) and an "outside" measurement (on the side opposite from the noise source) to be stored in separate memories. The NIC contour algorithms are then applied to show the subtracted curve with the NIC contours (and, in the case of Ivie's IE‑45, a calculation of the NIC number is also displayed.)
Ivie has developed a new process called "Continuous NIC” (C‑NIC) which allows continuous NIC measurement in real time. C‑NIC allows for real time on‑site evaluation of transmission conditions through a barrier between two spaces. With C‑NIC you can “sniff out” weak spots in isolation material in real time, on site. For more information: C-NIC.PDF (128 KB)