Apogee MQ-500 PAR PPFD Quantum Meter | 0-4000 micromol/m2/s, plus or minus 5%

Apogee MQ-500 PAR PPFD Quantum Meter for Lab-Grade PPFD Readings

The Apogee MQ-500 is the meter most commercial growers reach for when canopy maps need to hold up to a state inspector. A blue-enhanced silicon photodiode plus a custom optical filter holds calibration uncertainty within plus or minus 5% across the 400-700 nm PAR band. Measurement runs to 4,000 micromol/m2/s — past the saturation point of any LED or HPS in production. Long-term drift is under 2% per year. The meter you calibrate today still reads honestly through next quarter's bloom cycle.

Daily Workflow with the MQ-500 Quantum PPFD Meter

Spot mode gives an instant PPFD. Sample mode averages a quick canopy walk. Log mode records DLI in mol/m2/day over the full photoperiod. The cosine-corrected 180 degree field of view keeps off-axis light from flattering the number. That matters most when checking the corners of a 5x5 footprint. Growers typically hold the meter at canopy height during a slow walk-through, several inches above the leaf surface, sweeping fixture by fixture. Handheld at 24x24x126 mm. Light enough for a one-hand sweep between feed cycles.

Key Features

• Spectral range: 400-700 nm PAR with blue-enhanced silicon detector and custom filter
• Measurement range: 0-4,000 micromol/m2/s, beyond saturation for any production LED or HPS
• Calibration uncertainty: Within plus or minus 5% — the spec growers quote when defending canopy data
• Long-term drift: Less than 2% per year, so quarterly recalibration is not mandatory for in-house use
• Field of view: 180 degree cosine-corrected, so off-angle light does not inflate edge readings
• Logging: Spot, sample, and log modes; DLI output in mol/m2/day over the photoperiod
• Build: Anodized aluminum sensor housing, epoxy-potted, dome diffuser submersible to 30 m
• Warranty: 4-year manufacturer warranty, longer than most consumer-grade PAR meters

Technical Specifications