DNT WeatherScreen PRO Bedienungsanleitung Seite 87

(4 ) Mustonly becorrectedif the sensorwas not set up exactlyonthe windvaneholderaccording
to the cardinal directions,see chapter 4.
(5 ) The conversionfactor on factory settings is basedon the factor for bright sunlight of 126,7 lux
per w/m2.This is matchedto the spectralsensitivityof the humaneye.Forother applications,
e.g. if the value is to be used for photovoltaic applications or the assessment of plant growth,
other spectral sensitivity ranges apply.The display must be adjustedaccordingly.
(6 ) Wind speed is highly dependenton ambient conditions and the location.Therefore,it is difficult
to calibrate. In this case,the rule of thumb for the distance to buildings or other high obstacles
is: distance = 4x (building height minus mounting heightof the sensor).Installationon a roof, in
particular,can becritical due to the widely differing wind pressureconditions(upwind,downward
wind, suction, distractions by chimneys nearby,trees etc.). For example, suction and shading
effects on a flat roof can causethe displayof a much too slow wind speedas well as if the station
is in the lee (currently facing away from the wind) of a pointed roof or chimney.
Bearingwear on the anemometercan also causefalsifying effects over long periods.
Anexactcalibration is only possiblein direct comparisonwith a calibratedanemometerand under
absolutelythe same and constantflow velocityof the air.
(7 ) Therain flow meteris calibratedwith factory settings basedonthe funnel diameter.Thecounting
rocker tilts every 0.1 mm and emits a counting pulse.
A correctioncanbe madewith a sight glass raingaugewith a calibratedscaleandwith anopening
of at least 10.16 cm
Youcan enter a standard value for rain quantity counts over longer periods (e.g. you can read
it at a weather station in the same or nearby placevia the internet portal) if the weather station
was not in operation over one of the listed intervals (daily/ weekly / monthly/ annually)in order
to continue collecting the concrete data at the location itself from this base.
Further notes
- Please note that weather forecasts are highly location dependent. Especially in places that undergo
rapid weather changes,e.g. certain mountainousregions,valleys etc., there are swift changesin
air pressure. In such locations, the weather forecast display of the weather station can only work to
a limited extent.
Since the weather forecast is based solely on the air pressure trend over 24 to 48 hours, the weather
forecast can only be about 70 % accurate. Professional weather services use other means, such as
weather radars, computer weather models, and detailed geographic data for accurate forecasting.
- The station or sensors are calibrated at the factory. Technical wear of sensors, e.g. in the case of
humidity sensors, can lead to deviations after a long period of operation. However, only calibrate
your station if you can use a calibrated (laboratory) measuring device.
- Never calibrate your sensors based on data from third parties such as the radio, internet, newspaper,
etc. The weather station has the task of recording the data precisely at its location.
- The sensor for the UV index can deliver falsified results over time due to varying solar radiation. If
you wish to use it professionally, it must be calibrated every 2 to 3 months using a calibrated UV
measuring device.
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