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The light meter’s measurement should now be four times as much due to the inverse square law. Then move your meter closer to the light by cutting the distance in half. You can easily test this yourself by taking a measurement at any distance from a light source. If a meter doesn’t measure linearly, it cannot be calibrated as the reading will always be off by a different amount. This means if the light intensity doubles, the reading should be twice as much too. The meter’s reading must be proportional (i.e.
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If you want to dig deeper into light meter accuracy, consider the ISO/CIE 19476 standard.
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Measuring light accurately is very hard to achieve, so a meter with an error of ☒0% can be considered as accurate enough for most applications. Obviously, a measurement device should provide accurate measurements. These are the four most important aspects of a plant light meter app: Accuracy If you’re looking for a light meter for applications other than plant lighting such as photography, health, or architecture, check out the Light Meter LM-3000 for exactly that.
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