The CS125 uses the well-established forward scatter system for visibility measurement, using a 42° scatter angle, which gives accurate estimates of Meteorological Observable Range (M.O.R.) for fog and snow.
It identifies precipitation particles from their scattering properties and fall speeds, and combines this with a temperature measurement to identify the weather type. It has downward-pointing optics that reduce the risk of contamination of the optics and blockage with snow. Interference to the sample volume from the sensor by flow distortion or heat is minimized.
It also provides reliable present weather information in the form of SYNOP codes, including information on the intensity of precipitation. Accumulation can also be reported.
The CS125 uses continuous high-speed sampling to reduce errors during mixed-weather events and events that return intermittent signals, such as rain and hail, while still providing reliable readings during more stable events, such as fog and mist. The CS125 has high immunity to interference from the visible and infrared warning lights used to mark obstructions, such as wind turbines.
The sensor can be set to a lower sampling frequency to save power, if required.
The CS125 incorporates low-power dew prevention heaters, as well as higher-power anti-icing heaters for the hoods as standard. These heaters are automatically controlled to ensure operation in all weather, or they can be disabled individually to save power.
The CS125 continuously monitors its own status and will report internal faults and contamination or blockage of the sensor lenses. It also has two user-configurable alarm outputs that can be used to drive audio or visual alarms using solid-state relays.
The CS125 is certified by Deutscher Wetterdienst as suitable for use to control wind turbine obstruction light systems as specified by 506/04, General Administrative Rules for the Identification of Aircraft Obstructions.
|Maximum Reported Visibility||75 km (46.6 mi)|
|Minimum Reported Visibility||5 m (16.4 ft)|
|Resolution||1 m (3.28 ft)|
|Outputs||Present and past weather: identifies as standard mist, fog, drizzle, freezing drizzle, drizzle and snow, rain, freezing rain, rain and drizzle, rain and snow, and snow. 56 SYNOP present weather codes and associated METAR and NWS present weather codes - hail detection option; past weather code option.|
|Precipitation Detection Sensitivity||0.05 mm/h|
|Accumulation Reporting Range||0 to 999.9 mm (0 to 39.37 in.)|
|Accumulation Resolution||0.1 mm (0.0039 in.)|
|Rain Intensity Range||0 to 999.9 mm (0 to 39.37 in.)|
|Intensity Resolution||0.1 mm (0.0039 in.)|
|Operating Temperature Range||-25° to +60°C (standard)|
|Extended Operating Temperature Range||-40° to +70°C (This extended version is available as a special. Contact Campbell Scientific for more information.)|
|Operating Humidity||0 . . . 100%|
|Operating Wind Speed||Up to 60 m/s|
|Sensor Sealing||Rated to IP66|
|Total Unit Power||Less than 3 W while sampling continuously (including dew heaters)|
|Material||Stainless steel and hard-anodized aluminum powder-coated|
|Mountings||Stainless-steel clip on V-bolt mounting to pole with diameter of 32 to 52.5 mm (1.26 to 2.07 in.)|
|Mounting Pole||An optical mounting pole is available to place the sample volume at 1.5 m (4.9 ft), as recommended by the WMO.|
|Frangible Mast||Frangible masts are available to customer requirements to meet ICAO recommendations (typically placing the sample volume at 2.5 m [8.2 ft]).|
|Sensor Dimensions||540 x 640 x 246 mm (21.26 x 25.2 x 9.7 in.) including mount|
|Cable Length||5 m (16.4 ft)|
|Sensor Weight||~3 kg (6.61 lb) dependent upon mounting system|
Lower power states can be achieved by less frequent sampling and remote control of heaters.
Optional power supplies with battery backup available.
Connectors in place of flying leads are available.
A low-voltage shutdown level can be set to prevent backup batteries from being damaged.
|Electronics Supply Voltage||7 to 30 Vdc|
|Hood Heater Supply Voltage||24 V (dc or ac)|
|Hood Heater Power||2 x 30 W (total of 60 W)|
|Dew Heater Power||2 x 0.6 W (total of 1.2 W)|
|Serial Interface||RS-232 or RS-485|
|Serial Data Rates||1200 to 115,200 bps (38,400 bps default rate)|
|Alarm Outputs||2 x 0 to 5 V outputs, 32 mA (max)|
Lens contamination circuity monitors both the source and detector lenses for contamination/blockage at 1 s intervals.
The sensor can be configured to adjust calibration for low to moderate window contamination.
Light source stability control ensures stable operation through variations in temperature and with sensor aging.
Corrected at 1 s intervals.
|Emitter Light Frequency||850 nm|
Please note: The following shows notable compatibility information. It is not a comprehensive list of all compatible products.
Campbell Scientific has introduced a new operating system, OS13, for the CS120A visibility sensor and CS125 present weather sensor. It is fully backwards compatible and is easily installed on all CS120A and CS125 sensors (but not older CS120 sensors). OS13 is available free of charge and can be downloaded here or supplied by email on request.
Upgrade to OS 13 is recommended.
Changes to both CS120A and CS125
To optimise user calibrations, OS13 temporarily disables hood heaters during calibration and resumes normal hood functionality once the calibration is complete.
Hood heaters now operate down to the fault alarm levels of -56°C, but will turn off at low temperatures if a thermistor fault is detected.
OS13 better flags DC saturation, which under very bright conditions might occasionally produce a dirty lens alarm.
OS13 has corrected the potential for level 1 dirty window alarms to occur during heavy fog and rain where visibility drops below 10m.
Changes to CS125 only
OS13 contains improved filtering to reduce the occurrence of short duration precipitation reports caused by transient insect activity. The sensor still retains its sensitivity to the detection of precipitation.
Automatic optimisation to differing background light levels reduce the occurrence of erroneous particles reported in bright light.
OS13 includes a software switch to turn off BCFG from the CS125 message output. If triggered by broken fog, the BCFG message could affect AWOS systems. This does not affect the CS120A.
Campbell Viewpoint is viewing software designed to accompany the Campbell Scientific optical sensor range, including the CS135 ceilometer, SkyVUE PRO, SkyVUE 8, SkyVUE 8M, CS120A visibility and CS125 present weather sensors. It is free to download (or via email on request) and use for 100 hours, after which you will need to purchase a key to continue using it.
Viewpoint version 188.8.131.52 has introduced our new ceilometer sensors to the list of instruments that can be monitored. This includes the SkyVue PRO, SkyVUE 8 and SkyVUE 8M.
Previous sensors are still available.
Version 184.108.40.206 also includes some minor bug fixes and improvements to the help menu.