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Apogee Waterproof Quantum Sensors

Measure PAR to ensure proper light levels for underwater photosynthesis

Apogee Instruments Quantum Meters accurately measure an aquariums range of photosynthetically active radiation (PAR) to give a better understanding of where to place aquatic specimen for optimal health. Measuring PAR output can assist in lighting configuration, tank arrangement, lighting malfunctions, and bulb replacement.

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Aquarium Application
PAR requirements of coral varies greatly due to different depths and water conditions they naturally exist in. Each tank setup requires a unique type, intensity, and duration of light, which can be determined easily using the Apogee Instruments Quantum Meter. Further information to determine aquatic specimen health can be found by asking a professional aquarist, becoming involved in a local reef club, through articles such as Photosynthesis and Photoadaptation by Sanjay Joshi, and through videos of our MQ-200 meter in action.
  How It Works
To ensure an aquarium specimen is receiving proper light, or photons, aquarium lighting can be tested for quantum or PAR outputs. PAR is the energy source required for photosynthesis, created by photons in the wavelengths of 400-700 nm, and can be measured from both sunlight and electric lighting sources. The energy source, PAR, is expressed in Photosynthetic Photon Flux, PPF, units µmol mˉ² sˉ¹.
PAR Meter; Aquarium
Spectral Error Reduction
Sensor head features a unique blue diffuser to reduce spectral error to less than 5%, for sunlight and common electric plant lights, and less than 10%, for LEDs. When high precision is required correcting for spectral errors of common electric lights can be used to correct minimal spectral errors.
  Ideal for Underwater Use
Separate potted solid, completely-sealed sensor head has no hollow cavities for water to penetrate and cause measurement errors.
Datalogging Capabilities*
The MQ-200 meter includes manual and automatic datalogging features for spot-check measurements or daily light integral calculations.
*PAR readings can be made using a stand-alone quantum sensor head, SQ-100 series, with a high-quality voltmeter. To use the voltmeter connect the positive lead of the voltmeter to the red wire of the SQ and the negative lead of the voltmeter to the black wire of the SQ. To get the unit µmol mˉ² sˉ¹ multiply the mV reading by 5.0. Voltmeters with mV setting attain the best resolution.
  Warranty and Support
All Apogee products are backed by an industry-leading four year warranty and outstanding customer support.



Correcting for Spectral Errors of Common Electric Lights

Quantum Meter; Aquarium

The reef tank lighting market has recently grown exponentially with hundreds of lighting options now available, due to the increased popularity of reefkeeping. Unfortunately, all types of electric lights have a unique spectrum, and therefore also yield a unique set of spectral errors when measured by any commercially available PAR meter. In response to emerging electric lighting technologies, Apogee has done extensive research to help customers make accurate PAR readings. Spectral errors for different commercially available lights were determined via the method proposed by Federer and Tanner (1966). These results are found in the table below.

The spectral errors of common lights such as CWF, CF, MH, and HPS are fairly straight forward. To make a high precision PAR reading for these types of lights, simply recalculate the PAR reading given by the meter with the corresponding percent error from the table below to yield a more precise PAR measurement. LEDs present a challenge when attempting to make accurate PAR measurements. With commercially available PAR meters, certain colors of LED tend to read high, while others read low. When used properly, the MQ-200 offers a very reliable and economical solution for precisely measuring the PAR output of LEDs. To achieve the highest level of accuracy, simply recalculate the PAR reading given by the meter with the corresponding spectral error percentage from the table below.
Federer, C.A. and C.B. Tanner, 1966. Sensors for measuring light available for photosynthesis. Ecology 47:654-657.

Apogee PAR Sensors Spectral Errors Under Electric Lights

All Quantum/ PAR sensors on the market experience a certain level of error under different electric light sources. The following data can be used to adjust the PAR readings of Apogee Quantum sensors to achieve highly accurate readings. Please note these errors apply only to quantum sensors that are pre-calibrated for electric lights and to the Quantum Meter when it is set to "electric light" mode.

LED Type Error [%] for Apogee
Quantum Sensor
Other Electric Lights Error [%] for Apogee
Quantum Sensor
Cool White -4.2 T5 Cool White Flourescent 0.0
Neutral White -6.1 T8 Cool White Flourescent -0.3
Warm White -9.9 T12 Cool White Flourescent -1.2
Blue (448 nm) -10.7 Compact Flourescent -0.2
Green (524 nm) 5.8 Metal Halide -3.9
Red (635 nm) 4.7 High Pressure Sodium 0.8
Red, Blue 2.7
Red, Green, Blue 3.5

CLICK HERE for more information about error correction



The MQ-200 is recommended and sold by some of the biggest names in the aquarium industry:

Aquarium Specialty, Bulk Reef Supply, Premium Aquatics, Vivid Aquariums, Orange County Aquarium Supply



Check out some of our favorite videos from around the web showing the MQ-200 in action:





Click here to view our full line of Quantum sensors