Visibility Sensor (MOR in m) | Smart Hardware Applications

MOR (m)Meteorological optical range, output unit: meters

10 m～75 kmTypical range (by order code)

RS485 / wireless uplinkModbus RTU, LoRaWAN, 4G/NB optional

Outdoor housingIP65, optional IP67 / explosion-proof

Product overview

The visibility sensor measures meteorological visibility and reports meteorological optical range MOR in meters (m). That reading can sit with background luminance and present weather in an RVR chain. The usual principles are forward scatter or transmission. Calibrate on site with a standard target, a collimator, or a transfer standard, and balance window soiling, heater defog, and power. The core is built for wide temperature, wide supply, and EMC. Signed firmware can be verified and rolled back, which suits a long outdoor life and remote service.

RS485 / Modbus RTU and industrial terminals are standard, with optional LoRaWAN or 4G/NB for a short-delay path to the cloud. The sensor can join traffic weather, a port VTS, civil-aviation ground observation, or a general IoT platform. SimtoLink supplies a point table, northbound MQTT/HTTP examples, and status-code definitions. Volume orders can set mounting height, the sample period, protocol mapping, and a calibration certificate.

Reliability outdoors

The housing is sealed and earthed for a pole, a gantry, and coastal salt spray. Ports are protected against surge and reversed polarity. Transmit and receive paths are laid out apart so they do not crosstalk. High salt and strong sun can take a corrosion-resistant coating, a sun hood, and a higher IP rating.

Visibility thresholds, soiling and maintenance flags, and data-quality codes are available, depending on the model and the protocol. Configuration and firmware update over the air. Acceptance is a power-on self-test, time sync with the master station, and an MOR comparison against a parallel instrument or a manual observation. For civil aviation or a metrology chain, SimtoLink can help with a third-party test and the type-test file.

Key specifications

The table is a typical build, for selection and for a tender clause. A wider range, redundant power, or an intrinsically safe version is in the hardware specification and the installation and commissioning guide. Order codes in the family can differ slightly. The nameplate and the papers shipped with the sensor govern.

Parameter	Specification	Notes
Measured quantity	Meteorological Optical Range (MOR)	WMO visibility definitions; in service it usually sits with an RVR chain
Output units	Meters (m)	If the platform joins an international system, convert to nautical miles or feet there
Typical range	10 m～75 km	Changes with the optical design and the order code; the specification governs
Measurement principle	Forward scattering / transmission type	Choice depends on mounting height and baseline length
Sampling and output	1 s～10 min configurable	Averaging windows for traffic control, civil aviation, or research
Power supply	DC 12～24V (typical)	Wide supply; isolated type optional
Communication interface	RS485 Modbus RTU	LoRaWAN, 4G/NB, or Ethernet, by model
Protection level	IP65	Outdoor build optional to IP67
Operating temperature	-40～60 ℃ (typical)	A cold-climate build can be ordered; a heated window changes the power budget
Calibration and maintenance	Standard target / optical calibration device	Set the window-clean and calibration interval from the site

Typical deployments

Three layouts that show up on IoT jobs, for the design and for a payback check:

Highways and urban expressways

Points along the road report MOR (m) live, and a threshold can drive a message sign, a speed limit, and a sound-and-light warning. Several probes together cut false alarms from a single dirty window.

Airports and general aviation

One visibility input in the RVR chain, with background luminance and a present-weather sensor. Time sync, status codes, and maintenance flags can be mapped to the civil-aviation exchange.

Harbors, channels, and pilotage

Wharf and channel-light visibility goes to the VTS and the pilot station, for a sailing window. In salt spray, clean the window more often and pick the corrosion-resistant build.

Installation, grounding, and maintenance

Before the sensor is powered, confirm the supply range and polarity. If the drawing is thin, measure bus voltage and breaker rating with a multimeter.
Run the communications cable as shielded twisted pair, grounded at one end, and do not lay it for a long distance in the same bundle as high-power cable.
On the bench, finish a two-way read and write and a threshold trip against the platform before the sensor goes on the pole.
An outdoor mount needs a path for water to leave and air to move. Recheck the seal face. Lightning-earth resistance has to meet the local rule.
In long service, compare MOR (m) against a reference and clean the optical window on the stated interval, and archive the quality log.

Ordering, documentation, and support

Ask SimtoLink for the hardware specification, an outline drawing, the wiring table, and a sample project. A volume order can include a sample review and an inspector at the plant. Warranty and calibration follow the contract and the papers packed with the sensor.

Where the reading is used

Visibility is a threshold for traffic control, port dispatch, and aviation weather, and it is often read with PM and humidity when a haze event is explained. The jobs below differ in mounting height, the maintenance window, and what the alarm is allowed to do.

Highway patchy-fog warning

Points sit about every 100 m along the road. A visibility threshold drives a message sign, speed guidance, and a sound-and-light warning. On the edge, several probes and other weather elements cut false alarms from one dirty window, for graded traffic-police control and an insurance risk model.

Harbor and channel pilotage

Docks, anchorages, and channel lights report visibility live to the VTS and the pilot station, for tug assignment and a berthing window. An automatic salt-spray wash and anodic protection keep the optical window in service longer and cut time the port is stopped.

Airports and general-aviation fields

Forward scatter or transmission is one step in the RVR chain, with a background-luminance meter and a present-weather sensor. Time sync, status codes, and maintenance flags follow the civil-aviation weather exchange.

Review of a heavy urban pollution event

Gridded visibility is read with PM2.5 and relative humidity to tell hygroscopic growth from dust. That supports a check of the emergency plan, of emission cuts, and of source reading, for an environmental inspection.

Visibility Sensor