Introduction to Sensor
The SQ-421X-SS Quantum Sensor is a digital sensor designed for accurate PPFD (Photosynthetic Photon Flux Density) and PAR measurements using the SDI-12 communication protocol. Calibrated for sunlight, it includes automatic immersion correction for underwater measurements. Its rugged, self-cleaning housing and reliable cable design make it suitable for outdoor fields, greenhouses, growth chambers, plant canopies, and aquatic environments.
Specifications
Specifications
| Parameter | Specification |
|---|---|
| Input Voltage Requirement | 5.5 to 24 V DC |
| Current Draw | 1.4 mA (quiescent); 1.8 mA (active) |
| Calibration Uncertainty | ±5% |
| Measurement Repeatability | Less than 1% |
| Long-Term Drift (Non-Stability) | Less than 2% per year |
| Non-Linearity | Less than 1% (up to 2500 µmol m⁻² s⁻¹) |
| Response Time | 0.6 s; detector signal reaches 95% following a step change. Fastest SDI-12 data transmission rate: 1 s |
| Field of View | 180° |
| Spectral Range | 370 to 650 nm (wavelengths where response is greater than 50% of maximum) |
| Directional (Cosine) Response | ±5% at 75° zenith angle |
| Temperature Response | Less than 0.5% from −20 to 50 °C |
| Operating Environment | −20 to 60 °C; 0 to 100% relative humidity; submersible up to 30 m depth |
| Dimensions | 30.5 mm diameter × 37 mm height |
| Mass | 140 g (with 5 m cable) |
| Cable | 5 m two-conductor, shielded, twisted-pair wire; additional cable available in 5 m increments; TPR jacket; pigtail lead wires |
| Warranty | 4 years against defects in materials and workmanship |
| Manufactured | Assembled in the USA |
Features
Applications