A light or UV budget tracks how much exposure a sensor has accumulated over time, rather than checking each reading against a range. You set one on a climate rule.
For the difference between a reading and an accumulated total, see What is a climate rule.
Setting a budget
Budgets are set in Step 2: Thresholds of the climate rule wizard, either when you create a rule or when you edit an existing one. Toggle on Cumulative Light Exposure for a light budget, or Cumulative UV Exposure for UV. A rule can carry both, and can carry them alongside ordinary temperature, humidity, lux, and UV thresholds.
Each toggle opens four fields:
- Max budget: the total exposure permitted before the budget is reached. Light budgets are expressed in klx-h, where 1 klx-h is 1,000 lux hours.
- Warning when exceeding: the percentage of the budget at which your first alert is sent. Choose it to suit how much notice you need. At 80% you have a fifth of the budget still in hand, which leaves time to adjust lighting, rotate an object, or review a display. A higher figure brings the warning closer to the limit.
- Start Date: the date from which Custodian begins accumulating. Set this to the date a display opened, or to the beginning of your reporting year.
- Cycle: tick Reset budget and choose a period, such as Yearly, and the accumulated total returns to zero at each interval. Conservation figures are written per year, so a yearly cycle matches them directly.
How a budget differs from a threshold
A threshold checks the reading in front of it, and a sensor moves in and out of range all day. A budget keeps a running total instead.
That total only goes up. Every hour of light a sensor sees is added to it, and nothing takes it back off, so there is no warning band to fall back out of. The total keeps climbing until the cycle resets it to zero and counting starts again.
What happens when a budget is passed
Custodian records two events for each budget: one when your warning percentage is passed, and one when the full budget is reached.
Both are recorded in the Threshold Events tab of the rule, and both can be sent to people if a notification rule covers them. In the notification setup, they appear as triggers alongside the rule's ordinary thresholds, so you can alert on the warning only, on both, or on neither. See Setting up notifications for a rule.
Without a notification rule, the events are still tracked and visible in Custodian, but no email or SMS goes out.
Which sensors are covered
The budget belongs to the rule, and every sensor you assign to that rule is tracked against it individually. Two sensors on the same rule therefore share one budget figure but keep separate running totals, so a case in a bright gallery reaches its warning long before one in a dim store.
Only sensors that measure light or UV accumulate against a light or UV budget.
Where to see progress
Once the rule is saved, you can follow a budget in four places:
- The Rules list shows the budget and its warning percentage as a badge beneath the rule name, for example 300 klx-h and 80%.
- The rule's Units tab shows each sensor's percentage of the budget used, in the Current State column.
- The rule's Threshold Events tab shows how far each sensor has climbed through the budget, and whether anyone has been notified.
- PDF reports include Lux Hours for lux sensors: the exposure accumulated across the report period.