Apogee S2-141 PAR-Far Red
Apogee PAR-FAR sensors combine two photodetectors that measure photosynthetically active and far-red radiation. The PAR sensor is the same as the Apogee model SQ-500 full-spectrum quantum sensor and is designed to measure photosynthetic photon flux density (PPFD, 400-700 nm). The far-red sensor is a quantum sensor that measures photons in the 700-760 nm range.
Typical Applications
- Monitoring plant light environments
- Research plant morphogenic activity
- Photobiology studies
Key Features
A domed diffuser promotes self-cleaning to minimize errors from dust and debris. 0-40mV output, SDI-12 version available (S2-441).
High Quality Cable
Pigtail-lead sensors feature on IP68, marine-grade stainless-steel cable connectors attached directly to the sensor head to simplify sensor removal for maintenance and recalibration.
Available Package
The S2-141 PAR-Far Red Sensor is also available as a package with a microCache Bluetooth micro-logger at a special introductory price.
Above: Spectral response of PAR detector (blue) and Far Red detector (red) compared to defined response of plants to radiation (dashed).
| Power Supply: | Self-Powered |
| Output (sensitivity): | 0.01 mV per μmol m⁻² s⁻¹ (PAR) 0.02 mV per μmol m⁻² s⁻¹ (Far Red) |
| Calibration Factor (reciprocal of sensitivity): | 100 μmol m⁻² s⁻¹ per mV (PAR) 50 μmol m⁻² s⁻¹ per mV (Far Red) |
| Calibration Uncertainty: | ± 5% |
| Output Range: | 0 to 40 mV (PAR) 0 to 20 mV (Far Red) |
| 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) |
| Response Time: | Less than 1 ms |
| Field of View: | 180° |
| Spectral Ranges: | 389 to 692 nm ± 5 nm (PAR) 700 to 760 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: | Anodised aluminium body with acrylic diffuser |
| IP Rating: | IP68 |
| Operating Environment: | -40°C to 70°C; 0 to 100% relative humidity |
| Dimensions: | 30.5mm diameter, 36.6mm height |
| Mass: | 51g |