Visibility sensor FT-N80

[device name]: visibility sensor

【Definition of Visibility】: Atmospheric visibility is defined as the maximum ground horizontal distance at which a person with normal eyesight can clearly see the outline of the target under the prevailing weather conditions.

[Function introduction]: The transmitter of the visibility sensor emits infrared light through the infrared LED light source. The infrared light source passes through a certain volume of air, and the infrared light source is scattered by gas molecules, aerosol particles, fog droplets, etc. in the air. The receiver of the visibility measuring instrument The visibility distance is determined by receiving the intensity of scattered light from the infrared light source, and the instrument can continuously measure the output of the visibility.

[Detection principle]: 35°forward scattering principle, more accurate measurement.

[Overall Appearance]: The overall embracing integrated design makes the layout of the internal cables more reasonable.

【Measuring components】: optical components lens, infrared led light source.

【Hardware Protection Design】:

①. The optical components are used with the lens facing down and with a protective cover, which can effectively prevent precipitation, droplets or dust from entering the lens, and reduce the pollution of the probe surface. This design provides accurate measurement results and reduces the need for maintenance.

②. The protective cover of the probe is made of aluminum alloy, and the surface is coated with anti-corrosion glass fiber coating.

③. The overvoltage and electromagnetic protection device of the visibility meter can ensure the long-term safe operation of the sensor.

④, Infrared LED light source, adding filter design, anti-light source interference.

⑤, low power consumption, internal circuit anti-interference design.

⑥. The DC power supply circuit of the instrument has double design of anti-reverse connection and self-recovery insurance.

[Equipment list]: 1 atmospheric visibility measuring instrument + 2 hoops.

【Installation Precautions】:

①. Install the visibility sensor about 2 meters away from the ground.

②. Ensure that there are no other objects below the visibility to interfere with the test.

③. The ideal installation site should be at least 100 meters away from large buildings or other facilities that generate heat and hinder rainfall, and also avoid the influence of tree shade.

④. The site should be free from obstacles, reflective surfaces and obvious sources of pollution that interfere with optical measurement.

⑤. Choose a suitable place to install the equipment. The equipment provides installation hoops. Use the hoops to install the equipment on a 75mm pole. In order to avoid light source interference, the transmitter must be on the south side.

[Power supply mode]: 10-30vdc wide voltage power supply.

【Measurement Range】: Default 0-800000m.

【Measurement error】: ≤1KM±2%; ±10%>1KM.

【Resolution】: 1m

【Update Interval】: 20s

【Mean time between failures】: (MTBF) greater than 18000 hours

【Working environment temperature】: -40~60℃

[Working relative humidity]: not more than 95% (30°C)

【Weight】: less than 10kg

[power consumption]: 0.5w

[Infrared light wavelength]: 870nm

【Signal output mode】: RS485, standard modbus-rtu protocol

【Types of measurable visibility data】:

①. Real-time visibility value

②, 10min average value of visibility

③. The average value of visibility in 1 minute

[Optical lens cleanliness level]: It can read the cleanliness of the infrared light emitting end and receiving end in real time. The cleanliness level is 1-5, and 5 represents the highest cleanliness. When the cleanliness is less than 3, the optical lens needs to be cleaned on site.

[Common sense of visibility]:

1. Visibility 20-30 kilometers, excellent visibility, clear vision

2. Visibility of 15-25 kilometers, good visibility and clear vision

3. Visibility 10-20 kilometers, general visibility

4. Visibility is 5-15 kilometers, the visibility is poor and the vision is not clear

5. Visibility is 1-10 kilometers, the visibility is poor in light fog, and the vision is not clear

6. Visibility 0.3-1 km fog visibility is very poor

7. The visibility is less than 0.3 kilometers, and the heavy fog has extremely poor visibility

8. Visibility is less than 0.1 kilometers and the visibility is extremely poor in dense fog