Museum & Archive Humidity Dashboard

The default band is 45–55% RH for mixed collections (≈50% ±5), with stability prized above the exact target. Treat it as a sensible starting point — your own specification, regulator, equipment manual or product datasheet sets the authoritative limits, and you can read your true band straight off the worst case those documents allow. Edit the readings against whatever band applies to you.

For most museum materials, yes. Mechanical damage comes from dimensional change as materials gain and lose moisture, so a steady 45% or 55% causes far less harm than constant cycling around 50%. Modern conservation guidance has relaxed toward broader but stable bands (and dew-point/seasonal-drift control) rather than tight, energy-hungry setpoints. The exceptions are moisture-sensitive specifics (metals want it drier, some organics damper) — but for mixed collections, prioritise stability and gradual seasonal change over a precise number.

Match the interval to the consequence and the rate of change: where an excursion spoils product or risks safety, log continuously (or as often as you can sample); where it is merely informative, daily or per-shift spot checks suffice. The in-range % and excursion count only mean something if your sampling is regular — sparse, irregular readings hide the excursions between them.

Yes — every reading is stored in this browser's localStorage on your device and nothing is uploaded to any server, which also makes the dashboard usable on sites with strict data policies. For shared, audit-grade records across a team or for regulatory retention, export the values into your own system.