README.html (version 4.3)

INFO-FILE FOR THE METEOROLOGICAL STATION meteoLCD

This file contains all relevant informations concerning the meteorological station of the LYCEE CLASSIQUE DIEKIRCH (LCD). .

Please mail your correspondance to: francis.massen@ci.educ.lu


Attention: this file replaces the readme95.html. It does not contain any history or other information concerning the monthly data. These informations are included from January 1996 on as a ten line header in the monthly data file!!



1. Description of the meteorological station

Name:
Meteorological station of the LYCEE CLASSIQUE DIEKIRCH
Address:
LYCEE CLASSIQUE L-9233 DIEKIRCH (Luxembourg, Europe)
attn: Prof. Francis Massen, Physics Lab. tel: (352) 803218 fax: (352) 809584
email: francis.massen@ci.educ.lu
Base Model:
DELTA-T Weatherstation, connected to DL2 datalogger
manufacturer DELTA-T Devices Ltd 128 Low Road, Burwell, GB - Cambridge, CB5 OEJ

Coordinates:

Altitude:
218 meter above sea-level

Time:
UTC TIME, manually synchronised on DCF77 atomic clock
Measurement rate:
typically every minute, with average of 30 minutes stored.

2. SENSORS (in the order of their appearance in the data-files):
(
state: FEB 2003)
Channel no. Type Name & Unit Description
61 AN1 AirSpeed [m/s] air speed measured by cup-anemometer accuracy 1%; threshhold 0.2 m/s; digital output; older model
62 RG1 Rainfall    [mm] rain-fall measured by tipping-bucket device 0.2 mm per tip; expressed in mm per half-hour
1 TM1 Logger_T [C] Logger temperature, NTC sensor, serves as a check for critical high internal temperatures.
2 TM1 Air_Temp [C] Air_Temperature, NTC sensor in louvred enclosure, accuracy 0.1 degrees Celsius
3 %RH Air_Humi  [%] Relative air humidity, resistive sensor in louvred enclosure, accuracy better then 2%
4 AN3 Air_Velo   [m/s] air speed measured by cup-anemometer accuracy 1%; threshhold 0.2 m/s; analog output; new model
5 BS4 Air_Pres   [hPa] Local air pressure, NOT REDUCED TO SEA-LEVEL!!! Add 27.3 hPa to get sea-level barometric pressure, accuracy 1 hPa
6 ESR SolarKip [W/m2] Solar radiation (irradiance) in W/m2; CM21 high precision pyranometer from Kipp&Zonen. Ventilated. Old sensor SolarRad displaced to column 23
7 UVA UVA_DT [W/m2] Ultraviolet (UV-A region) sensor from Delta_T Devices, covering the spectrum from 320 to 400 nm. Output in W/m2.Spectral response curve is bell-shaped (slightly asymetric), with maximum 100% relative sensitivity at 370 nm. Bandwidth at -3db (70% rel.sens.) is from 357nm and 378nm; bandwidth at half maximum (50%) is from 352 to 382nm. Please read separate file UV_AB.html
8 UVB UVB_DT [mW/m2] Ultraviolet (UV_B region) sensor from Delta_T Devices, covering the spectrum from 280 to 360nm. Output in m W/m2 Spectral response curve is bell-shaped, with maximum 100% relative senssitivity at 313nm. Bandwidth at -3dB (70% rel. sens.) is from 304 to 323nm; bandwidth at half maximum (50%) is from 302 to 327nm (approx.) Please read separate file UV_AB.html
9 UVB UVB_Bio
[mMED/h]
Broadband Solar-Light 501A sensor measuring the effective UVB radiation, expressed in mMED/h 
( milli Minimal Erythema Dose per hour) 1 MED/h = 250 J/(m2*h) = 0.06944 W/m2 effective UV_B irradiance This precision broadband instrument is temperature- stabilized at 25 degrees Celsius.
Accuracy: within +/- 5% of daily total. Resolution better than 0.1W/m2. 
Please read separate file UV_AB.html
10 UVA UVA_Bio
[W/m2]
Ultraviolet Solar-Light 501A-UVA sensor measuring the UVA irradiance in the [320..400nm] wavelength region. Reading is in [W/m2] (Watt per square meters). Construction is similar to the UVB_Bio sensor; the precision broadband sensor is temperature-stabilized at 25 degrees Celsius.
Accuracy: within +/- 5% of daily total. Resolution better than 0.1W/m2
Please read separate file UV_AB.html
11 CO2 c(CO2) [ppmV] CO2 concentration of the air, expressed in ppmV (parts per million; 1 volume% = 10000 ppm). Very precise (better than 1%) sensor from Environnement SA. Recalibrated every 3 to 4 weeks.
12 KAI NTC_Air  [mV] Air temperature NTC sensor of the Kroneis dew-point sensor.Please read separate file dewpoint.html
UNRELIABLE! DO NOT USE THIS SENSOR ANYMORE! (02 Feb 2003)
13 KDE NTC_Dew [mV] Dew point NTC sensor from Kroneis.Please read separate file dewpoint.html
OUT OF ORDER! DO NOT USE THIS SENSOR ANYMORE! (02 Feb 2003)
14 OZO Ozone [ug/m3] Tropospheric ( = ground) ozone concentration in ug/m3 measured by O3 M41 Ozone Analyser from Environnement SA. Please read separate file o3_41m.html
15 WV2 Wind_Dir [degrees] Windvane from Delta_T Devices (0 degrees means wind blows from North, 90 degrees from East ...). Accuracy better than 2 degrees
16 NO2 c(NO2) [ug/m3] NO2 concentration in ug/m3 measured by the AC31M sensor of Environnement SA. Recalibrated every 3 to 4 weeks.
17 NO c(NO)   [ug/m3] NO concentration in ug/m3 measured by the AC31M sensor of Environnement SA. Recalibrated every 3 to 4 weeks.
18  UBT UVB_Tin [C] Internal temperature of UVB_Bio sensor. Should be close to 25 degrees C.
19 UAT UVA_Tin [C] Internal temperature of UVA_Bio sensor. Should be close to 25 degrees C.
20 GBT Globe_T
 [C]
Black Globe temperature sensor for the computation of the WBGT (Wet Bulb Globe Temperature = Heatstress-Index) . Installed 02_May_01.
Manufacturer: LSI, Italy
21 WBT Wetb_T [C]

__________

Wetb_T [R]
Wetbulb temperature sensor for the computation of the WBGT (LSI, Italy)
Look at picture!
The WBGT = 0.7*Wetb_T + 0.2*Globe_:T + 0.1 * Air_Temp
Heavy physical exercices should be avoided if WBGT > 30 C
_______________
Attention: starting 24Apr03 the original Pt100 sensor has been replaced by a Pt1000 element: the data column of channel 21 gives now the resistance of this sensor: the temperature in C can be found by the formula:
temperature = (reading -1000)/3.85
22 DBT Dryb_T [C] Drybulb (=conventional) Pt100 temperature sensor (LSI, Italy)
Compute WBGT using the channel Air_temperature sensor from Delta_T.
This is done on the realtime graphs! (02 Feb 2003)
23 ESR SolarRad  [W/m2] Solar radiation (irradiance) in W/m2; silicon photodiode with reasonably flat spectral response from 400 to 1000 nanometer. Accuracy 1-2% (estim.)


Sampling for most sensors : 1 per minute, average over 30 minutes stored.
except: WV2: 1 measure per half-hour

3. DATAFILE FORMAT:

The data-files are self-explaining ASCII files, of the type 'comma and " separated columns'; they may readily be imported into:

Data-files usually cover a whole month, and contain 31*48 + 21 =  1509 lines for 31-days months (header = 21 lines).

Attention: There are several ERROR-FLAGS which may appear BEFORE (NOT AFTER!) the data:


4. Graphs displayed on the Internet (www.restena.lu/meteo_lcd)

The graphs are made using a Linux system, running GNUPLOT and IMAGE MAGICK and a couple of self-written Perl scripts.
A Win98SE computer running AUTOMATE 4 Pro makes the transfer from the logger to the Linux computer (transfer 2 times per hour); the Linux computer makes the daily and global files, creates the graphs and icons and transfers everything via a leased 256kbs line to the Internet provider.


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