How do light intensity meters work

While a sphere is capturing all of the light emitted, a light meter is capturing the amount of light at one particular spot or distance from the light. There are many types of light meters and new ones are being developed all the time. It is important to find a light meter from a reputable company that is inclusive of the entire spectrum. Skip to content. English Spanish French. How Light Intensity is Measured.

There are a few different ways to measure umols from a light source: Integrating Sphere Spectroradiometer Goniophotometer Light Meter. Goniophotometer A goniophotometer is similar to an integrating sphere because it provides the same type of data , but it expands on that data and is captured by a different means.

Light Meter Another way to measure intensity is by using a light meter. We use cookies on our website to give you the most relevant experience by remembering your preferences and repeat visits. Do not sell my personal information. Manage consent. Close Privacy Overview This website uses cookies to improve your experience while you navigate through the website. Out of these, the cookies that are categorized as necessary are stored on your browser as they are essential for the working of basic functionalities of the website.

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You also have the option to opt-out of these cookies. T here are several types of lighting metrics and measurements used in the lighting industry. While these are useful to lighting experts, how do these terms relate to the real world? We need a little context. A typical classroom, for example, is recommended to have a light level of around footcandles or lux. Compare this to a professional laboratory which the lighting standards recommend have a light level of footcandles or lux.

The recommendations are based on years of visual testing to determine how much light the human eye needs to properly see different tasks with varying levels of detail. You can see from this example how specific environments have very different light level requirements.

To further explain this, you might be thinking about the biggest natural light source we have — the sun. Examples of common light levels:. The light meter has a sensor that measures the light falling on it and provides the user with a measurable illuminance reading. These handheld devices are commonly used by photographers to help calculate proper light exposure. However, they are also an essential tool that are used to measure and verify light levels in the built environment.

Light meters are an especially useful tool if you are measuring light for safety or over-illumination, which cause eye strain and waste energy. An added advantage of using a lux meter is that they can be calibrated. Why is this important? Add to this, different wavelengths emit different intensities of light. This is why lux meters are configured to CIE standard illuminant A. A standard lux meter is essential to measure incandescent lighting, but what about LED lighting?

LED lighting has become increasingly common in commercial environments because of energy-efficiency, longevity, color temperature tuning, safety, and low maintenance.

Using a light lux meter is the best way to measure light intensity — it gives us the ability to choose the optimal light intensity for an environment. From a central area of the space, ensure your light meter is set up to record your new reading.

Simply subtract the ambient light level from the illuminated level — known as the differential or delta measurement, this is the amount of light the existing luminaires produce. With this light measurement unit, you can asses how it compares to the optimal lighting levels required. For open office lighting or a corridor, the reading you get from your light meter should, in theory, be consistent. Light intensity affects the way humans live, work and interact.

More recently researchers have discovered how light affects our health and well-being. Research has shown that while standard artificial light meets our visual needs, it is not sufficient to provide proper biological signals that our bodies and brains need and can even have a negative impact on our long-term health. We live in indoor environments that are too dim for our brains to identify as daytime and too bright at night for our brains to recognize as nighttime.

For example, think about the brightly-lit grocery store you go to late in the evening or the dim lecture hall or conference room you might spend the middle of your day — this is completely the opposite of the light signals around which our bodies evolved. Without proper daylight exposure and because we remain more active in brighter environments at night, our sleep-wake cycles, which are directly linked to our circadian rhythms and melatonin production the key sleep hormone — become dysregulated.

In order to get adequate and restful sleep which promotes daytime wakefulness and increased energy levels, mood and productivity; we need a well-functioning circadian rhythm. When this happens, we have improved sleep quality, allowing our circadian systems to repair both our bodies and our minds. Studies have also shown that proper daytime light signals also affect serotonin 1 , the precursor to melatonin. Having a unit of measurement and a device to measure it can be useful for determining and comparing different environments more specifically.

You might find, for example, that a specific range of lux is the most comfortable for you to read a book. These measurements can be used for designing buildings, such as schools, to ensure there is the right amount of light for different areas and activities. Depending on your phone or the app you used the range of values you were able to measure might have been limited.

Some apps, for example, might not display decimal readings, making it difficult to measure light levels below 1 lux in other words, even if the real reading is 0. This would be most common in very dark locations, such as inside a closet or outside at night.

The maximum reading could also be limited by the app or the phone's or tablet's hardware. You might, for example, only see a reading of 10, lux outside in direct sunlight—even if you expected a reading of 30, lux or more. This is useful to remember when using any measuring device. Just as the length of a ruler can't reflect the full length of a soccer field—or a kitchen thermometer couldn't tell us the temperature of the sun's surface—many digital measuring tools aren't able to provide a complete range of possible measurements.

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Go Paperless with Digital. Key Concepts Physics Light Measurement Mathematics Introduction Did you know you can use a smartphone as a scientific instrument to explore the world around you? Materials Smartphone or tablet with internet access and permission to download and install an app Adult to help verify and download the app Different light sources flashlight, lamp, ceiling light, etc.

Different locations dark closet, room with windows, outdoors, etc. Ruler optional Preparation Ask an adult to help you search for a "lux meter" or "light meter" app on a smartphone or tablet. There are many free options available note that some apps might have ads or in-app purchases enabled.

Get to know your lux meter app. Some apps will just display a number on the screen, whereas others will display a meter or a graph. Some will also let you record data. Make sure the app is working: move your phone from a dark room to a bright room, or hold it close to a light bulb bulbs are also hot as well as bright, so be careful here , and you should see the numbers fluctuate.

Locate the light sensor on your device. It is usually near the top on the front of the phone the side with the screen. You can do this by running your fingertip over the surface of the phone while your lux meter app is open.

When your finger covers the light sensor the reading should drop. Make sure you do not accidentally cover the sensor while doing the activity.