OWNER’S MANUAL QUANTUM METER Models MQ-500 APOGEE INSTRUMENTS, INC. | 721 WEST 1800 NORTH, LOGAN, UTAH 84321, USA TEL: (435) 792-4700 | FAX: (435) 787-8268 | WEB: APOGEEINSTRUMENTS.COM Copyright © 2018 Apogee Instruments, Inc.
TABLE OF CONTENTS Owner’s Manual ............................................................................................................................................................................... 1 Certificate of Compliance ......................................................................................................................................................... 3 Introduction ..........................................................................................................
EU Declaration of Conformity This declaration of conformity is issued under the sole responsibility of the manufacturer: Apogee Instruments, Inc.
Radiation that drives photosynthesis is called photosynthetically active radiation (PAR) and is typically defined as total radiation across a range of 400 to 700 nm. PAR is often expressed as photosynthetic photon flux density (PPFD): photon flux in units of micromoles per square meter per second (µmol m-2 s-1, equal to microEinsteins per square meter per second) summed from 400 to 700 nm (total number of photons from 400 to 700 nm).
Apogee MQ series quantum meters covered in this manual are self-contained and come complete with handheld meter and sensor. Sensor model number and serial number are located on a label on the backside of the handheld meter.
Calibration Uncertainty Measurement Range Measurement Repeatability Long-term Drift (Non-stability) Non-linearity MQ-500 ± 5 % (see calibration Traceability below) 0 to 4000 µmol m-2 s-1 less than 0.
Spectral Response Mean spectral response measurements of six replicate Apogee SQ-100 (original) and SQ-500 (full-spectrum) series quantum sensor. Spectral response measurements were made at 10 nm increments across a wavelength range of 300 to 800 nm in a monochromator with an attached electric light source. Measured spectral data from each quantum sensor were normalized by the measured spectral response of the monochromator/electric light combination, which was measured with a spectroradiometer.
Cosine Response Directional, or cosine, response is defined as the measurement error at a specific angle of radiation incidence. Error for Apogee SQ series quantum sensors is approximately ± 2 % and ± 5 % at solar zenith angles of 45° and 75°, respectively. Mean cosine response of seven apogee SQ-500 quantum sensors. Cosine response measurements were made on the rooftop of the Apogee building in Logan, UT.
Apogee MQ series quantum meters are designed for spot-check measurements, and calculation of daily light integral (DLI; total number of photons incident on a planar surface over the course of a day) through the built-in logging feature. To accurately measure PFFD incident on a horizontal surface, the sensor must be level. For this purpose, each MQ model comes with a different option for mounting the sensor to a horizontal plane. The AL-100 leveling plate is recommended for use with the MQ-500.
MQ series quantum meters are designed with a user-friendly interface allowing quick and easy measurements. To power the meter, slide the included battery (CR2320) into the battery holder, after removing the battery door from the meter’s back panel. The positive side (designated by a “+” sign) should be facing out from the meter circuit board. Press the power button to activate the LCD display.
Reset: To reset the meter, in either SMPL or LOG mode, push the mode button three times (RUN should be blinking), then while pressing the down button, press the mode button once. This will erase all of the saved measurements in memory, but only for the selected mode. That is, performing a reset when in SMPL mode will only erase the manual measurements and performing a reset when in LOG mode will only erase the automatic measurements.
Spectral Errors for PPFD and YPFD Measurements with Apogee SQ Series Quantum Sensors Radiation Source (Error Calculated Relative to Sun, Clear Sky) Sun (Clear Sky) Sun (Cloudy Sky) Reflected from Grass Canopy Transmitted below Wheat Canopy Cool White Fluorescent (T5) Metal Halide Ceramic Metal Halide High Pressure Sodium Blue LED (448 nm peak, 20 nm full-width half-maximum) Green LED (524 nm peak, 30 nm full-width half-maximum) Red LED (635 nm peak, 20 nm full-width half-maximum) Red LED (668 nm peak, 20 nm
-2 -1 s ] at each wavelength between 300 and 800 nm by relative quantum yield and summing the result. This is defined as yield photon flux density (YPFD) -2 -1 s ] (Sager et al., 1988). There are uncertainties and challenges associated with this definition of PAR. Measurements used to generate the relative quantum yield data were made on single leaves under low radiation levels and at short time scales (McCree, 1972a; Inada, 1976).
McCree, K.J., 1972b. Test of current definitions of photosynthetically active radiation against leaf photosynthesis data. Agricultural Meteorology 10:443-453. Sager, J.C., W.O. Smith, J.L. Edwards, and K.L. Cyr, 1988. Photosynthetic efficiency and phytochrome photoequilibria determination using spectral data. Transactions of the ASAE 31:1882-1889. Underwater Measurements and Immersion Effect When a quantum sensor that was calibrated in air is used to make underwater measurements, the sensor reads low.
Moisture or debris on the diffuser is a common cause of low readings. The sensor has a domed diffuser and housing for improved self-cleaning from rainfall, but materials can accumulate on the diffuser (e.g., dust during periods of low rainfall, salt deposits from evaporation of sea spray or sprinkler irrigation water) and partially block the optical path. Dust or organic deposits are best removed using water, or window cleaner and a soft cloth or cotton swab.
Homepage of the Clear Sky Calculator. Two calculators are available: one for quantum sensors (PPFD) and one for pyranometers (total shortwave radiation). Clear Sky Calculator for quantum sensors. Site data are input in blue cells in middle of page and an estimate of PPFD is returned on right-hand side of page.
Verify Functionality Pressing the power button should activate the LCD and provide a real-time PPFD reading. Direct the sensor head toward a light source and verify the PPFD reading responds. Increase and decrease the distance from the sensor to the light source to verify that the reading changes proportionally (decreasing PPFD with increasing distance and increasing PPFD with decreasing distance). Blocking all radiation from the sensor should force the PPFD reading to zero.
Error Codes and Fixes Error codes will appear in place of the real-time reading on the LCD display and will continue to flash until the problem is corrected. Contact Apogee if the following fixes do not rectify the problem. Err 1: battery voltage out of range. Fix: replace CR2320 battery and perform master reset. Err 2: sensor voltage out of range. Fix: perform master reset. Err 3: not calibrated. Fix: perform master reset. Err 4: CPU voltage below minimum.
RETURN POLICY Apogee Instruments will accept returns within 30 days of purchase as long as the product is in new condition (to be determined by Apogee). Returns are subject to a 10 % restocking fee. WARRANTY POLICY What is Covered All products manufactured by Apogee Instruments are warranted to be free from defects in materials and craftsmanship for a period of four (4) years from the date of shipment from our factory.
How To Return An Item 1. Please do not send any products back to Apogee Instruments until you have received a Return Merchandise Authorization (RMA) number from our technical support department by calling (435) 792-4700 or by submitting an online RMA form at www.apogeeinstruments.com/tech-support-recalibration-repairs/. We will use your RMA number for tracking of the service item. 2. Send all RMA sensors and meters back in the following condition: Clean the sensor’s exterior and cord.
