PAR meter

Description

A PAR meter measures light relevant to photosynthesis, commonly reporting photosynthetic photon flux density (PPFD) in micromoles per square metre per second. PAR is typically defined over 400–700 nm. For an aquarium, the useful reading is at the measurement position, rather than a lamp’s wattage or a visual brightness judgment. Choose a sensor intended for the light source and underwater use. An air-calibrated sensor may need an immersion correction. Apogee’s MQ-510 incorporates its underwater correction in the meter firmware; that correction should not be applied again or copied to another model. Take spot measurements at the positions and depths you want to compare, keeping the sensor level for a horizontal reading. Record sensor position and lighting settings so later measurements are comparable. A sensor wand can help reach positions in the aquarium without moving the sensor by its cable. Protect the handheld display as its instructions require: the MQ-510 sensor and cable may enter the water, but its meter is not waterproof. Keep the sensor clean and follow calibration guidance. A PPFD reading describes the light at that point; it is not a universal target for every plant, coral or lighting schedule.

Source

• apogeeinstruments.com — https://www.apogeeinstruments.com/content/MQ-510-manual.pdf

Further reading on identification and aquarium care.