Description
Apogee SQ-522-SS — Full-Spectrum Quantum PAR Sensor with Modbus Digital Output
The Apogee SQ-522-SS is a professional-grade, full-spectrum quantum PAR sensor designed for accurate and continuous PPFD measurement across all light sources — including narrow-band LEDs. Built for commercial growers, researchers, and greenhouse engineers who need data they can trust, the SQ-522-SS outputs a digital signal via Modbus RTU protocol over RS-232 or RS-485, making it ideal for integration with dataloggers, controllers, and building management systems.
With a spectral range of 389–692 nm (±5 nm), the SQ-522's full-spectrum response significantly outperforms traditional quantum sensors when measuring LED grow lights — giving you accurate readings rather than misleading estimates.
Key Features
- 🌱 Full-spectrum quantum sensor — spectral range 389–692 nm ±5 nm for accurate LED PAR measurement
- 📡 Modbus RTU digital output — RS-232 or RS-485 compatible, PPFD returned in digital format
- 🏗️ Rugged self-cleaning housing — anodized aluminium body with cast acrylic diffuser
- 🔌 Pre-tinned pigtail leads — easy connection to dataloggers and controllers
- 📏 NIST-traceable calibration — sensor-specific calibration coefficients programmed at the factory
- 💧 Suitable for aquatic environments — including salt water aquariums and coral growing
- ☀️ Minimal azimuth error — typically less than 0.5%
Typical Applications
- PPFD measurement over plant canopies in greenhouses, growth chambers, and outdoor environments
- Reflected and under-canopy (transmitted) PPFD measurement
- Commercial and research greenhouse facility monitoring (e.g. Syngenta, Embrapa-scale installations)
- Multi-zone PAR measurement integrated with dataloggers and environmental controllers
- Aquatic PAR measurement — coral growth, saltwater aquariums
Technical Specifications
- Output: Modbus RTU (RS-232 / RS-485)
- Spectral Range: 389–692 nm (±5 nm)
- Housing: Anodized aluminium with acrylic diffuser
- Calibration: NIST-traceable, factory-programmed sensor-specific coefficients
- Azimuth Error: <0.5%
- Cable: High-quality, pre-tinned pigtail leads
- Mounting: Compatible with Apogee AL-120 solar mounting bracket (sold separately)
What's in the Box
- Apogee SQ-522-SS Quantum Sensor
- Cable with pre-tinned pigtail leads
- Protective blue cap
Datalogger, mounting bracket, and controller sold separately. Requires a Modbus-compatible measurement device supporting the Read Holding Registers (0x03) function.
Why Buy From The Hydro Bros?
We supply professional-grade horticultural equipment to commercial growers, research facilities, and serious hobbyists across the UK and internationally. Need a quote for multiple units or a commercial project? Get in touch with our team directly and we'll put together a tailored quotation for you.
