Weather Sensor Transmitters 4~20mA Environmental monitoring probe sets Anemometer (wind speed) Wind vane Light energy sensor (pyranometer) Solar radiation shield - model THP-CL Humidity sensor Temperature sensor Weather sensor transmitters - mounting methods
4~20mA Environmental Monitoring Probe Sets Aegis Safety has a range of weather sensor transmitters available which use the industry standard 4~20mA output signal loop (loop powered). This allows for easy integration into a SCADA or PLC monitoring system. Weather sensor transmitters are tools for the observation and recording of meteorological data. The sensors can monitor air temperature, humidity, barometric pressure, light energy, wind speed and wind direction. Ordering information for fully mounted systems WS3-WD-TB-CL Wind speed 3 cup, wind direction, mounted on T Bar mounting arm c/w 5m cable WS3-WD-LE-TB-CL Wind speed 3 cup, wind direction, light energy, mounted on T Bar mounting arm c/w 5m cable Options WS6 Fit WS6 (wind speed 6 cup), instead of WS3 on the above T Bar options (used for lower starting speeds) THP-CL Temperature and humidity, both housed in solar radiation shield c/w 5m cable on the above T Bar options
Anemometer (Wind Speed) The anemometer is used for the measurement of wind velocity. The TruTrack anemometer is manufactured from stainless steel and anodised aluminium so as to provide minimum maintenance and maximum reliability. Three cup anemometer specifications Range 0~55m/s Accuracy ± 2% Start speed 1.5m/s Output The anemometer can be supplied witha  4~20mA output or pulse (switch closure). 4~20mA output is: 4mA at 0m/s 20mA at 60m/s Pulse output is 2 pulses per metre The anemometer is supplied attached to the T Bar equipment mounting arm. Options are available to supply free standing or on a base mounting plate for attaching to posts or buildings. There is also a six cup anemometer available if the application requires lower starting speeds (= 0.45m/s)
Wind Vane The wind vane is manufactured from stainless steel and anodised aluminium so as to provide minimum maintenance and maximum reliability. Range 0° ~ 360° Accuracy ±5% Dead band 20° (350° ~ 10°) Output The wind direction vane has a 4~20mA output 4~20mA output is: 4mA at 0° north 12mA at 180° south 20mA at 360° north The wind direction vane is supplied attached to the T Bar equipment mounting arm. Options are available to supply free standing or on a base mounting plate for attaching to posts or buildings.
Pyranometer (Light Energy Sensor) The pyranometer (light energy sensor) has been designed to provide a wide spectral response, a good cosine response and los susceptibility to inaccuracies caused by rain drop and dirt effects. Range 0~1500w/m2 Accuracy ±5% Cosine error is typically less than 3% from vertical to 85° in all directions Temperature coefficient 0.15% per 1°C The light energy sensor is supplied attached to a T Bar equipment mounting arm. Options are available to supply free standing, or on a base mounting plate. The pyranometer uses a polycrystalline silicon solar cell to measure the incoming global solar radiation. This gives good accuracy without the expense and maintenance required by a thermopile pyranometer. It also provides a flatter spectral response than the photo diodes that are frequently used for this type of sensor. The pyranometer has a relatively large surface compared to many photo diode sensors. This minimises inaccuracies caused by the effect of rain drops and dirt on the surface. The sensor has a slightly domed top to facilitate rain drainage. Dirt sitting on the surface of the sensor is dispersed by rain flowing off the dome. Spectral Response The full terrestrial solar spectrum deposits measurable energy at the earth's surface in the range of 287 nanometers (nm) to 4000nm and beyond. However, the pyranometer measures the radiation between 300 and 1100nm. As over 90% of the solar energy is between 300 to 1100nm, the pyranometer is calibrated so as to estimate the short-wave component of the solar radiation.   Cosine Response The ideal pyranometer collects radiation from horizon to horizon and should therefore have a reception angle of 180° in all directions. In reality, some low angle radiation will not be detected because of the geometry of the sensor but this has been minimised by the sensor head design. The cosine error for this pyranometer is typically less than 3% from vertical to 85° in all directions. Other sources of error The polycrystalline silicon solar cells have a temperature coefficient  of 0.15% per 1°C . The pyranometer is calibrated at 20°C giving a possible 3% error from 0°C to 40°C. The output of all radiation sensors tends to decrease over time as the detector ages. Previous calculations estimate that the average decrease of the sensor is between 1% and 2% per year.
Solar Radiation Shield - Model THP-CL The solar radiation shield is a chamber made from a series of fins that use the natural convection of warm air to draw fresh air into the chamber and expel the heated air. Temperature, humidity and pressure sensors that are placed within the chamber will experience a flow of fresh air and so will give more accurate measurements than sensors that are exposed to direct sunlight. The fins are made from spun aluminium with a powder coated white finish. The solar radiation shield is connected to the T Bar equipment arm. This is the most convenient way of mounting the shields to a tower, post or building. The ventilated chamber within the solar radiation shield is cylindrical in shape, 90mm high and 50mm in diameter. This chamber is surrounded by a stainless steel mesh grill to protect the sensors from insects and wind blown debris. If sunlight falls onto sensors, they absorb radiant energy directly from the sunlight and are therefore at a higher temperature than the surrounding air. This causes erroneous readings. If the sensors are put into a chamber so that the direct sunlight can not strike them but the chamber and the air within it are heated, this will also cause erroneous readings. If the chamber can be ventilated so that any heated air is able to rise and escape through convection and fresh air drawn from outside the chamber, then the sensors will be able to provide an accurate reading of air temperature, humidity and pressure.
Humidity Sensor The Humriel HS1101 humidity sensor provides: Instantaneous de-saturation Solid polymer structure High resistance to chemicals Fast response time Range 0%~100% Accuracy RH±5% Humidity sensor housed inside solar radiation shield
Temperature Sensors The temperature sensor is a high accuracy thermister that has been factory calibarated to within 0.2°C. This alleviates the need for any user calibration. The sensor has low thermal mass so as to ensure a fast response time. The temperature sensor is housed inside the solar radiation shield. Temperature Range -30°C ~ 70°C Accuracy ±0.3°C from (0°C ~ 50°C)
T Bar The T Bar is specifically designed to give good separation between wind speed anemometers and wind vanes. The total length of the T Bar is 800mm. The bar has a 41mm U section and is supplied with a plastic capping strip. The arm has an attachment plate in the centre with holes that can be used for mounting to 50mm or 25mm diameter pipe or bolting to posts or buildings. The arm is supplied complete with two 50mm U bolts.
Base Mounting Plate The base mounting plate is used to facilitate the attachment of wind vanes, anemometers and solar radiation sensors to posts or buildings. Two counter-sunk holes in the centre of the plate are used to attach the base. The two outer holes are then used to attach the base to a post or building. The outer holes are 5mm in diameter and 55mm apart. There is a groove in the plate to allow the cable (from the centre of the base) to emerge at the side of the base mounting plate. A neutral cure translucent marine silicone rubber is used to seal the base to the base mounting plate.