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Lux level field measurement "above roof level" of a building

Bindu

An end client requested a measurement that, to the best of my knowledge, does not seem technically feasible. I'm wondering if anyone has encountered a practical way to approach this.

A building has been constructed within an existing "artificial valley" surrounded by woodland and hills which raise above the building. Client wants to have a measurement on field of the lux level above the building and at level with the surrounding landscape. In such environment, even night light will contribute so the measurement should somehow isolate the contribution from artificial lighting only.

They say it's for environmental reason but sounds to me like an excuse to tell us we haven't accomplished the scope but perhaps I'm not updated.

Measurements around the building have already been provided, we just miss the measurements "above".

Do you have expertise in doing so or reference to standards / technical guides that would help me in challenging the request?

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  • 0

    If they really want to know by measurement, pick a night with no moon (moon phase calcs here ) and fly recording or telemetry sensors  on a drone. For tests at  ground level the usual is to measure with and without the device under test lights on and calculate a difference.

    Its not really clear to me what the purpose is here however - is this some sort of stealth building, with a maximum permitted skyshine - commonly done by calculation and tests of the chosen lamp fittings in isolation for things like Football or Rugby Stadia *, or is it the case that folk work on the roof and must have at least some safe level of illumination to move about, like the top floor of a multistorey car-park or a roof garden.

    Mike.

    * This calculation does not always work well - the floodlights may beam onto the pitch, with low up-lighting but in rain or snow, there is secondary scattering from the rain drops that increases the skyshine in bad weather. Luckily no-one usually hangs about to make a measurement and quibble under those conditions.

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  • 0

    If they really want to know by measurement, pick a night with no moon (moon phase calcs here ) and fly recording or telemetry sensors  on a drone. For tests at  ground level the usual is to measure with and without the device under test lights on and calculate a difference.

    Its not really clear to me what the purpose is here however - is this some sort of stealth building, with a maximum permitted skyshine - commonly done by calculation and tests of the chosen lamp fittings in isolation for things like Football or Rugby Stadia *, or is it the case that folk work on the roof and must have at least some safe level of illumination to move about, like the top floor of a multistorey car-park or a roof garden.

    Mike.

    * This calculation does not always work well - the floodlights may beam onto the pitch, with low up-lighting but in rain or snow, there is secondary scattering from the rain drops that increases the skyshine in bad weather. Luckily no-one usually hangs about to make a measurement and quibble under those conditions.

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