A climate rule is a reusable set of climate thresholds. You define it once and apply it to any number of sensors across your sites, rooms, and collections. Instead of configuring thresholds sensor by sensor, you create a rule and assign it wherever it is needed.
This keeps your monitoring consistent, which is especially useful if you have many sensors or follow standard conservation guidelines across your institution.
Default rules
Custodian includes built-in default rules for your sensors. Default rules are always present and cannot be deleted. No configuration is needed, but you can edit it if necessary to suit your needs.
Connection alert settings are managed from a centralised view. From here you can see at a glance whether an alert will be sent when a unit goes offline, and how many people will be notified by email/SMS. This saves you from having to check each sensor individually.
Your created rules
You can create as many rules as you need. Each rule has its own set of thresholds for the metrics you want to monitor: temperature, humidity, lux, or UV. A rule can also set a light budget, which tracks total exposure over time rather than single readings. You can assign each rule to any number of specific sensors.
You can create as many active rules as you need. For example, you might have one rule for a general gallery space and a stricter one for a storage room containing sensitive objects.
Each active rule shows:
- The thresholds it monitors, displayed as a range (for example, 15 to 25 °C for temperature)
- The units currently assigned to it, with their current readings and notification status
- Tabs for Units, Notification Rules, and Threshold Events, where you view its sensors, manage notifications, and track progress against any budget it sets
Light budgets
A threshold looks at the reading in front of it. A budget adds up every reading since counting began.
Lux measures brightness at a single moment. Lux hours measure brightness multiplied by time, so a dimly lit case left on all year can accumulate more exposure than a brightly lit one shown for a fortnight. Light damage adds up and cannot be reversed, which is why conservation guidance is usually written as a yearly exposure limit rather than a brightness limit.
Custodian measures accumulated exposure in klx-h, where 1 klx-h is 1,000 lux hours. Take a display case lit at 100 lux, open 10 hours a day, 300 days a year:
- In a day: 100 lux × 10 hours = 1 klx-h
- In a year: 1 klx-h × 300 open days = 300 klx-h
Against a 1,000 klx-h annual budget, that case uses under a third. Halve the lighting to 50 lux and it uses a sixth.
A rule sets its budget for light. You give it a total, a start date, and a percentage at which you want early warning. Custodian then tracks every sensor assigned to the rule against that budget and alerts you twice: once when the percentage is passed, and again when the budget is reached. See How to create a climate rule to set one up.
Once the rule is saved, its budget and warning percentage sit under the rule name, and the Units tab shows how much of the budget each sensor has used.