The MQ-500 quantum meter is the tool of choice for scientists all over the world to accurately measure photosynthetically active radiation from all light sources. It has a hand-held meter, attached via cable, that displays and stores measurements. The sensor incorporates a blue-enhanced silicon photodiode and custom optical filters with a rugged, self-cleaning sensor housing design, anodized aluminum body with acrylic diffuser. Typical applications include PPFD measurement over plant canopies in outdoor environments, greenhouses, and growth chambers, and reflected or under-canopy (transmitted) PPFD measurements in the same environments. Quantum sensors are also used to measure PAR/PPFD in aquatic environments, including salt water aquariums where corals are grown.
The meter has a sample and log mode, and will record an integrated daily total in mol m-2 d-1. Sample mode will record up to 99 manual measurements. Log mode will power the meter on/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. The meter can store up to 99 averages, once full it will start to overwrite the oldest measurement with new ones. An integrated daily total will be recorded from the 48 averaged measurements (making a 24 hr period). Sample and log measurements can be reviewed on the LCD display or by downloading the data to a computer, however, the integrated daily total can only be viewed by downloading the data to a computer. Downloading data to a computer requires the AC-100 communication cable (a standard USB cable will not work) and ApogeeAMS software.
For a limited time, when purchased on our website from inside the USA, the meter comes with free shipping and a free neoprene carrying case (a $12 value).
For instructions on how to use the meter for underwater measurements, see this page for the immersion effect correction factor or consider purchasing the MQ-510.
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• AC-100: Communication Cable (Required to download data to a computer)
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The MQ-500 is a full spectrum quantum sensor with a spectral range of 389 to 692 nm ± 5 nm, which can be seen in the graph below. This improved spectral response of this new meter increases the accuracy of LED measurements when compared to our previous original models.

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