Introduction to Sensor
The S2-442-SS PAR-FAR Sensor is a rugged two-channel digital sensor designed to measure PAR (PPFD) and far-red photon flux from electric grow lights. Using the Modbus communication protocol, it provides measurements of traditional quantum flux, far-red photon flux (700–750 nm), and the far-red fraction. Its fully submersible aluminum housing and IP68 marine-grade connector make it suitable for demanding controlled-environment and agricultural applications.
Specifications
Specifications
| Parameter | Specification |
|---|---|
| Power Supply | 5.5 to 24 V DC |
| Current Draw | RS-232: 37 mA; RS-485: 37 mA quiescent, 42 mA active |
| Calibration Factor (Reciprocal of Sensitivity) | Custom for each sensor and stored in firmware |
| Calibration Uncertainty | ±5% |
| Measurement Repeatability | Less than 1% |
| Long-Term Drift | Less than 2% per year |
| Non-Linearity | Less than 1% up to 4000 µmol m⁻² s⁻¹ (PAR); less than 1% up to 1000 µmol m⁻² s⁻¹ (Far-Red) |
| Field of View | 180° |
| Wavelength Ranges | 389–692 nm ±5 nm (PAR); 700–750 nm ±5 nm (Far-Red) |
| Directional (Cosine) Response | ±2% at 45°; ±5% at 75° zenith angle |
| Temperature Response | Less than 0.1% per °C |
| Housing | Anodized aluminum body with acrylic diffuser |
| IP Rating | IP68 |
| Operating Environment | −40 to 70 °C; 0 to 100% relative humidity |
| Dimensions | 30.5 mm diameter × 37 mm height |
| Mass | 140 g (with 5 m cable) |
| Warranty | 4 years against defects in materials and workmanship |
| Manufactured | Assembled in the USA |
Features
Applications