Apogee MQ500 Full Spectrum Quantum PAR Meter

For Scientists and Serious Growers

The MQ-500 full-spectrum quantum meter is the premium tool of choice among leading scientists and serious growers for accurately measuring the photosynthetically active radiation (PAR) from all light sources. An accurate quantum light meter is critical for measuring the intensity of light used in the precision growing of plants and other photosynthetic organisms in greenhouses, growth chambers, farms, gardens, aquariums, and other agricultural systems.

Quantum Light Meter

Unlike commonly available LUX or footcandle meters used for measuring light for human vision, our meters feature a laboratory-grade PPFD (photosynthetic photon flux density), or “quantum,” optical detector precisely calibrated to measure the light intensity in µmol m-2 s-1 of the specific colour wavelengths emitted by LEDs, HPS, MH, sunlight and other light sources that are utilized by plants for photosynthesis.

Rugged & Easy to Use

Quantum sensor uses a precision silicon photodiode detector, a custom optical filter, and an acrylic diffuser all housed in a self-cleaning, dome-shaped, anodized aluminium sensor head. The sensor head is potted solid with epoxy for years of use in harsh environments, including underwater. The handheld meter is attached by a cable and displays real-time readings, records samples, and logs average intensity and daily light integral (DLI) measurements. Unlike the blue sensor head, the handheld meter is not waterproof.

Extremely Accurate & Stable

Precisely measures and combines the intensity of all photons between 400 and 700 nm to give a single PAR reading in µmol m-2 s-1 within 5 % uncertainty. Unlike hobby-grade PAR meters, our meter has a stable, accurate calibration with an accuracy drift rate of less than 2% per year.

Three Measurement Modes

The meter has a spot measurement, sample, and log mode and will record an integrated daily total in mol m-2 s-1. Sample mode will record up to 99 manual measurements and log mode will power the meter on and off to make a measurement every 30 seconds. Every 30 minutes, the meter will average the sixty 30 second measurements and record the averaged value to memory, up to 99 averages. Once full, it will overwrite the oldest measurements with new ones. A daily light integral will be recorded from the 48 averaged measurements for a day’s worth of readings and is downloadable via Apogee AC-100 cable.

How is the MQ-500 different from previous Apogee quantum sensors?

The MQ-500 is a full spectrum quantum sensor with an optimized, highly accurate spectral measurement range of 400-700 nm, which can be seen compared to our older "original" quantum sensor in the graph below. The improved spectral response of this new meter greatly increases the accuracy of LED measurements when compared to their previous "original" models.

Where is the MQ-500 used?

The MQ-500 is used to measure incoming PPFD measurements in outdoor environments, greenhouses, growth chambers, and aquariums.



Calibration Uncertainty

± 5 %

Measurement Range

0 to 4000 µmol mˉ² sˉ¹

Measurement Repeatability

Less than 0.5 %

Long-term Drift (Non-stability)

Less than 2 % per year

Non-linearity

Less than 1 % (up to 4000 µmol mˉ² sˉ¹)

Response Time

Less than 1 ms

Field of View

180 ˚

Spectral Range

389 to 692 nm ± 5 nm (wavelengths where response is greater than 50 % of maximum)

Spectral Selectivity

Less than 10 % from 412 to 682 nm ± 5 nm

Directional (Cosine) Response

± 5 % at 75 ˚ zenith angle

Azimuth Error

Less than 0.5 %

Tilt Error

Less than 0.5 %

Temperature Response

-0.11 ± 0.03 % Cˉ¹

Uncertainty in Daily Total

Less than 5 %

Detector

Enhanced silicon photodiode

Housing

Anodized aluminium body with acrylic diffuser

IP Rating

IP68

Operating Environment

0 to 50 C, less than 90 % non-condensing relative humidity up to 30 C, less than 70 % non-condensing relative humidity from 30 to 50 C, separate sensors can be submerged in water up to depth of 30 m

Meter Dimensions

126 mm length, 70 mm width, 24 mm height

Sensor Dimensions

24 mm diameter, 37 mm height

Mass

100 g (with 5 m of lead wire)

Cable

2m of two conductor, shielded, twisted-pair wire; additional cable available; TPR jacket

Warranty

4 years against defects in materials and workmanship

Manufactured

Made in the USA