Description
Add supplied illuminance exposure to a cumulative lux-hour record.
Conservation records distinguish measured areas, source-qualified condition labels, storage clearances and light exposure. Lux-hours measure photometric exposure, whereas material response depends on spectrum and sensitivity. A nominal inverse-square distance ratio or geometric mask share does not establish an appropriate treatment or safe display limit.
Add supplied illuminance exposure to a cumulative lux-hour record.
When to use this tool
Use Exhibit Cumulative Light Dose Step when you already have openingLuxHours, illuminanceLux, exposureHours and need to add supplied illuminance exposure to a cumulative lux-hour record.
How to use the tool and how it works
- Enter openingLuxHours, illuminanceLux, exposureHours. Use the units and conventions below.
- Run the tool. Correct any format, range, or cross-field input error before interpreting the output.
- Read closingLuxHours, addedLuxHours. Use the output convention below.
Require opening lux-hours, lux and hours>=0; added=lux*hours and closing=opening+added.1
Light exposure combines illuminance and duration, while damage also depends on material sensitivity and the light spectrum. An accumulated lux-hour value therefore needs context before it can support a conservation decision.2
| Input field | Meaning and units | Accepted input |
|---|---|---|
| openingLuxHours | Opening Lux Hours | Required. Finite number; minimum 0. |
| illuminanceLux | Illuminance Lux | Required. Finite number; minimum 0. |
| exposureHours | Exposure Hours | Required. Finite number; minimum 0. |
| Output field | Interpretation | Returned shape |
|---|---|---|
| closingLuxHours | Closing Lux Hours | Required. Finite number. |
| addedLuxHours | Supplied illuminance in lux times hours; photometric exposure rather than a material-independent damage measure. | Required. Finite number. |
{
"input": {
"openingLuxHours": 1000,
"illuminanceLux": 50,
"exposureHours": 8
},
"output": {
"closingLuxHours": 1400,
"addedLuxHours": 400
}
}Limitations and assumptions
- This uses constant or interval-mean illuminance. Lux-hours are photometric exposure, not a universal damage dose; spectral sensitivity, material response and a safe display limit are not determined.
- Inputs must satisfy both the field types and the cross-field conditions above. Invalid input causes an error; a successful false flag or documented placeholder is a different result.
- Numeric calculations use binary floating point unless exact decimal-integer arithmetic is explicitly stated. No hidden measurement tolerance or decimal rounding is added; nonfinite or out-of-contract results are rejected. Numeric signed-zero results are exported as zero.
Alternative or Complementary methods
Use calibrated observations and the complete conservation, lighting or transport assessment. Check material response, geometry, history and actual condition before applying local ratios, exposure terms or labels to an object.
References
-
Calculation and input contract: art-conservation/exhibit-cumulative-light-dose-step — tool.io
-
Agent of Deterioration: Light, Ultraviolet and Infrared — Stefan Michalski; Canadian Conservation Institute
Similar or alternative tools
- Display Spectrum Weighted Band Dose
Calculate a supplied sensitivity-weighted multiband exposure term.
- Conservation Light Distance Ratio
Calculate a supplied inverse-square irradiance distance ratio.