Dead volume
The volume outside of the column packing itself. The interstitial volume (intraparticle and interparticle volume) plus extracolumn volume (contributed by injector, detector, connecting tubing, and endfittings) all combine to create the dead volume. This volume can be determined by injecting an inert compound. For example, a compound that does not interact with the column packing. It is also abbreviated Vo or Vm
I really agree that consistency matters more than getting every parenting moment “right.” One thing that’s helped in our home is giving a warning before transitions, like leaving the park or starting bedtime—it cuts down on a lot of the pushback.