Product Overview
The OHTS1094 is a quantum sensor based on the photoelectric effect principle, designed to measure Photosynthetically Active Radiation (PAR) within the wavelength range of $400\,\mathrm{nm} \sim 700\,\mathrm{nm}$. The sensor employs a high-precision photoelectric sensing element with broad-spectrum absorption characteristics, offering high quantum responsivity within the $400\,\mathrm{nm} - 700\,\mathrm{nm}$ band and low annual drift. The sensing surface is equipped with an optical cosine corrector to ensure cosine response accuracy for incident angles, with the output signal maintaining a linear proportional relationship to direct radiation intensity.
The device features an all-aluminum alloy enclosure structure with an IP67 protection rating, incorporating a built-in spirit level and mechanical adjustment mechanism to support rapid field leveling. The communication interface utilizes an RS-485 bus, supporting the standard ModBus-RTU protocol, and can directly output instantaneous PAR values. It is suitable for long-term outdoor meteorological monitoring, agricultural ecological research, and plant physiological experiments.
Features
- Spectral response range strictly limited to the $400\,\mathrm{nm} \sim 700\,\mathrm{nm}$ photosynthetically active waveband
- All-aluminum alloy enclosure structure with IP67 protection rating for harsh outdoor environments
- Integrated bubble level and handwheel adjustment mechanism supporting field horizontal calibration
- Standard ModBus-RTU communication protocol compatible with industrial automation systems
- High-quality cosine diffuser ensuring cosine response accuracy for $0^{\circ} \sim 90^{\circ}$ incident angles
- Wide voltage power supply design supporting DC $7\,\mathrm{V} \sim 30\,\mathrm{V}$ input range
- Low power consumption design with quiescent power of $0.06\,\mathrm{W}$
- Fast response time reaching $0.1\,\mathrm{s}$
Applications
The OHTS1094 PAR sensor is ideal for meteorological observatory radiation monitoring, agricultural greenhouse light environment monitoring, and plant photosynthesis efficiency research. It supports forest canopy light interception measurement, grassland ecosystem energy assessment, and precision agriculture lighting control systems. Additional applications include atmospheric pollution optical depth studies, crop growth model parameter acquisition, agrivoltaics light resource assessment, and long-term ecological station observation.
Technical Specifications
| Parameter | Specification |
|---|---|
| Supply Voltage | DC $7\,\mathrm{V} \sim 30\,\mathrm{V}$ |
| Communication Interface | RS-485 (ModBus-RTU Protocol) |
| Power Consumption | $0.06\,\mathrm{W}$ |
| Operating Temperature | $-25^{\circ}\mathrm{C} \sim 60^{\circ}\mathrm{C}$ |
| Spectral Response | $400\,\mathrm{nm} \sim 700\,\mathrm{nm}$ |
| Measurement Range | $0 \sim 2500\,\mu\mathrm{mol}/(\mathrm{m}^{2}\cdot\mathrm{s})$ |
| Resolution | $1\,\mu\mathrm{mol}/(\mathrm{m}^{2}\cdot\mathrm{s})$ |
| Accuracy | $\pm 5\%$ ($1000\,\mu\mathrm{mol}/(\mathrm{m}^{2}\cdot\mathrm{s})$, @ 550nm, 60%RH, $25^{\circ}\mathrm{C}$) |
| Response Time | $0.1\,\mathrm{s}$ |
| Linearity | $\leq \pm 1\%$ |
| Annual Stability | $\leq \pm 2\%$ |
| Protection Rating | IP67 |
Physical Specifications
| Parameter | Specification |
|---|---|
| Enclosure Material | Aluminum Alloy |
| Mounting Method | Screw fixation (M3 mounting holes) |
| Protection Rating | IP67 |
FAQ
Q: What is the measurement range and spectral response of the OHTS1094?
A: The OHTS1094 measures Photosynthetically Active Radiation within the wavelength range of 400nm ~ 700nm with a measurement range of 0 ~ 2500 umol/(m2s) and resolution of 1 umol/(m2s).
Q: What is the protection rating and operating temperature range?
A: The sensor features an IP67 protection rating with an all-aluminum alloy enclosure, suitable for operating temperatures from -25°C ~ 60°C.
Q: How do I install and level the sensor correctly?
A: Use M3 screws through the mounting holes to secure the device to a mounting bracket, then adjust the base handwheel screws while observing the bubble level to ensure the sensing surface remains horizontal to the ground. Remove the optical protective cover before measurement.
Q: What should I check if the sensor shows continuous zero readings?
A: Check if the measurement environment has sufficient light source and confirm the optical protective cover has been removed. Also verify the power supply is within DC 7V ~ 30V range and check for correct wiring polarity.
Q: What communication protocol does the OHTS1094 support?
A: The sensor utilizes an RS-485 bus supporting the standard ModBus-RTU protocol with configurable baud rates of 2400, 4800, or 9600 bit/s. Factory default is 4800 bit/s.