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16 Cards in this Set
- Front
- Back
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What is the limiting factor for growing plants indoors?
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-light
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How can light be measured?
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-footcandle
-lux |
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What is a footcandle?
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-the unit of illumication equivalent to that produced by a standard candle at a distance of 1 foot
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What is lux?
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-the unit of illumination equivalent to that produced by a standard candle at a distance of 1 meter
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What are some scientific light terms?
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-candela
-lumen -photon flux -quanta -joules |
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What can affect light penetration into a room?
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-type (glass/plastic/glazing)
-reflection -barriers -orientation -latitude -geographic region |
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What color waves does chlorophyll often use?
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-blue and red
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What are the Pro's to incandescent bulbs?
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-small
-no special fixtures -dramatic -range of wattages available |
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What are the Con's to incandescent bulbs?
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-concentrated light
-only 7% usable energy in light -90% of energy wasted on heat -short life (750 hrs) -high in red/orange, low blue |
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What are the Pros to fluorescent tubes?
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-diffuse light
-efficient -22% of energy usable light -36% of energy wasted on heat -long life (8,000-9,000 hrs) |
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What are the Con's to fluorescent tubes?
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-work best if 70-90 degrees
-fixtures bulky -low far-red emission -light cannont be concentrated |
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What are the Pro's to sodium vapor lamps?
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-25-35% of energy visible light
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What are the Con's of sodium vapor lamps?
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-yellow/orange/red spectral emission only
-large ballast (special fixtures) |
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What are some ways to increase artificial light?
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-added white reflectors to fluorescent fixtures
-paint surrounding walls white -clean tubes to remove dust -change tubes regularly -keep plants centered under fluorescent tubes |
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What is the minimum light required for plant maintainance?
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-100 fc
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How do you find the amount of total light needed per day?
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-footcandles of light x hours of light/day
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