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 three built-in default rules, listed first in the Rules tab and marked (default rule): Connection, which watches for a sensor going Offline, Proximity, which watches for Object Present, and Water, which watches for Water Present. They are always present and cannot be deleted or archived. No configuration is needed, but you can edit them. They carry a pencil icon rather than the … menu your own rules have.
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 or UV 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
If a sensor reading falls outside the thresholds set in its assigned rule, this is reflected in the monitoring indicators across the Dashboard and Sites tab. for more details, see: Understanding the monitoring indicators.
Light and UV budgets
Temperature and humidity thresholds ask a question about the present moment: is this reading inside the acceptable range? A budget asks a cumulative question: how much light has this object received since we started counting?
Lux measures brightness at an instant. Lux hours measure brightness multiplied by time. A display case lit at a modest level for a full year can therefore accumulate far more exposure than a brighter case shown for a fortnight, even though the second case looks more aggressive on a graph. Because light damage accumulates and cannot be undone, conservation standards such as PAS 198 express light limits as an annual exposure allowance rather than as a maximum brightness.
Custodian measures accumulated exposure in klx-h, where 1 klx-h is 1,000 lux hours. Working it out takes two steps. Take a display case lit at 100 lux, open 10 hours a day, 300 days a year:
| Sum | Exposure | |
|---|---|---|
| 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 climate rule can carry a light budget, a UV budget, or both, set in Step 2 of the rule wizard. You define the total, the date counting begins, whether the count resets on a cycle, and the percentage at which you want early warning. Every sensor assigned to the rule is tracked against that budget, and you are alerted twice: once when your warning percentage is passed, and again when the budget is reached.