PAR light measurement: Evaluation of plant light source characteristics

Horticultural light performance metrics

If you’re interested in greenhouse light or plant development, you’ll find a wealth of information on the goods available from the manufacturers. Watts, lumens, lux, cd/m2, PAR (photosynthetically active radiation), photosynthetic photon flux density, photon flux density ppfd, photosynthetic photon flux ppf and photon efficiency are among them.
We’d like to provide you a quick rundown of which of these characteristics are truly significant to plant lighting evaluation and how they might be quantified.
The ability to perceive light is perceived differently by humans and many other animals than it is by plants. Depending on the wavelength, the eye is more or less sensitive to visual light.

PAR light measurement: Comparing horticultural lighting systems

The light sensitivity curve V (), which reaches its maximum at 555 nm, is used in daylight or photopic vision (yellow-green). Color-sensitive uvulae in the eyes allow us to perceive colors without hesitation. The par light sensitivity curve V ‚(), which reaches its maximum at 507 nm, is used in the case of night or scotopic vision (blue-green). We can see at these low levels of brightness because of light-sensitive rods to the human eye, yet we can no longer differentiate colors. Lumens, lux, and cd/m2 are all photometric metrics that reflect the brightness perception of humans in daytime vision.
Humans may use V () to study the light’s spectrum in that situation. Using traditional illuminance or luminance meters to evaluate plant illumination is hampered by the undervaluation of blue (400-500 nm) and red light (600-700 nm) in the visible spectrum. Unlike humans, plants rely on blue and red light for photosynthesis, which has a far lower sensitivity to these wavelengths. Therefore, the photometric measures described above are useless for assessing plant lighting.

PAR light from active photosynthetic processes

PAR refers to the portion of electromagnetic energy in the 400-700 nm visible light spectrum that causes photosynthesis. In the evaluation of horticultural lighting systems, the amount and spectral composition of PAR light are key aspects to consider. Factors to keep in mind when comparing lighting systems for horticulture include:
In terms of photosynthetic photon flow (PPF), how much PAR is generated by the system?

Spectrometers for smart lighting

Multimeter with LUX LED light source spectrometers for intelligent lighting Infrared light meters that use quantum physics Cookies Cookies can be used for a variety of purposes, including customizing content and adverts, facilitating social networking, and tracking website usage. Social media and advertising partners may combine information you’ve given them with information they’ve obtained from other services you’ve used.

PAR light measuring: Determining how much PAR is reaching the aquatic plants

Light is measured using par light photometry. There are a variety of options for adjusting various aspects of the camera’s operation at the LCD’s back. Displays such as ISO, aperture, exposure correction and light metering are shown on the back of the monitor. Many quick-access buttons surround the LCD, including those for autofocus, light metering, and continuous shooting, among others. There are numerous AF shortcuts, light metering shortcuts, and continuous shooting shortcuts all across the monitor.
Aquarium fans know that colorful lighting is unnecessary and that bright lighting has nothing to do with the quality of the lighting (e. g. fluorescent tubes in living rooms). 380 to 780 nm (blue to red) is the wavelength range that plants use for photosynthesis now after evolving over time. For the plant, these wavelengths are used by pigments like chlorophyll to store energy. The JBL LED SOLAR lamps must provide high PAR values for your aquarium plants to grow, according to JBL. The PAR value changes with increasing water depth, though.

How does PAR respond to various color temperatures?

When it comes to determining how the PAR value changes under water, no one has ever done it. The 1 meter-deep Koi aquarium at the JBL Research Centre was turned into a diving tank in order to find out. Biologist Heiko Blessin brought his diving suit and equipment so he could measure the lamps with a PAR meter while they were submerged. While carefully moving the sensor head toward the light at various depths with an underwater phone case, the PAR meter was reading the light. Elena Hänle, JBL’s chemistry expert, observed the maximum PAR value at each level of the outer pane.
For each measurement, data were taken at a distance of 10 centimeters from each side of the JBL LED SOLAR NATUR (5 centimeters above and 5 centimeters below). The measurements in the tables have been changed to account for the phone cover’s lowering effect.

What role does PAR light have in the growth of plants?

Because the illuminance in lux was always measured simultaneously using a lux meter, the lux values are also included in the table. With water depths as low as 40 cm, we could still observe PAR levels as high as 150 nm, which is wonderful news for aquarium plants! Aquarium owners will be delighted by the amazing plant growth that results from these exceptional qualities. The lux number, which is a good predictor of illuminance, was also taken into account. To put it another way, the lumen number is meaningless because increasing the green part of the spectrum does not impact the ability of plants to photosynthesise. Only when the full spectrum is combined with a high PAR value can we understand how well illumination can assist plant development.