Negative amplitude means the signal is attenuated relative to a reference point, so if you see e.g. -20dB, it means the signal is 1/10th of the reference value. dB on it's own is unitless, so you will see things like dBm (relative to 1mW â 0dB = 1mW), or dBV (relative to 1V â 0dB = 1V).
In Colorado, the offer is valid at the Denver Zoo and the Denver Art Museum. However, the Denver Art Museum is Sunday only, because they already offer free admission to everyone on the first Saturday of the month. This list does change, so check the Museums on Us website, before you go.
State Parks Discover Pass Free Days. Washington State Parks offers several free days when a Discover Pass is not required to visit a state park. Following are 2017 free days: Jan. 1 â First Day Hikes; New Yearâs Day. Jan. 15-16 â Martin Luther King, Jr. Day.