readme95.html
INFO-FILE FOR THE LCD METEO-STATION
This file contains all relevant informations concerning the meteorological station of
the LYCEE CLASSIQUE DIEKIRCH (LCD). It is also a LOG-FILE for occurring problems, changes
or other important news. These informations will simply be appended to the end of this
file.
Please mail your correspondance to: francis.massen@ci.educ.lu
Attention: this file has been replaced by readme.html
and stays here only for archiving proposes!
- version 2.0: 26_Jan_95: added remarks concerning rain-gauge errors when high wind (see
history log)
- version 2.1: 07_Jun_95: added informations concerning new UVB_Bio and CO2 sensors
- version 2.2: 14_Jul_95: added informations concerning new Kroneis Dew Point sensor
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.
Model:
DELTA-T Weatherstation, connected to DL2 datalogger; manufacturer DELTA-T Devices Ltd 128
Low Road, Burwell, GB - Cambridge, CB5 OEJ
Coordinates:
- 49 degrees 51 min 56 sec Latitude North
- 6 degrees 9 min 35 sec Longitude East
Altitude:
218 meter above sea-level
TIME:
UTC TIME, manually synchronised on DCF77 atomic clock
2. SENSORS (in the order of appearance in the data-file):
state: JUNE 95
- AN1 air speed measured by cup-anemometer accuracy 1%; threshhold 0.2 m/s
- RG1 rain-fall measured by tipping-bucket device 0.2 mm per tip; expressed in mm
per hour
- TM1 Logger temperature, NTC sensor, serves as a check for critical high
temperatures; disregard!
- TM1 Air_Temperature, NTC sensor in louvred enclosure accuracy 0.1 degrees Celsius
- %RH Air_Humidity in louvred enclosure accuracy better then 2%
- TM1 Soil_Temperature, NTC sensor insertet into brick wall; actually measures
temperature of the wall on top at the roof; specifications same as TM1 Air_Temperature
- BAR Real local air pressure, NOT REDUCED TO SEA-LEVEL!!! Add 27.3 HPa to get
sea-level barometric pressure SCXAN15 sensor from Sensortechnics, accuracy 1-2 HPa
- ESR Solar radiation (irradiance) in W/m2; silicon photodiode with reasonably flat
spectral response from 400 to 1000 nanometer. Accuracy 1-2% (estim.)
- UV_A Ultraviolet (UV-A region) sensor 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
- UV_B Ultraviolet (UV_B region) sensor covering the spectrum from 280 to 360nm.
Output in 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
- UVB_Bio Ultraviolet Solar 501A sensor measuring the UVB effective radiation,
expressed in mMED/h ( milli minimal erythema dose per hour) 1 MED/h = 210 J/(m2*h) =
0.00583 W/m2 effective UV_B irradiance Please read separate file UV_AB.html
- UVB_Tin The UVB_Bio sensor must be temperature stabilized at 25 degrees Celsius
approx. This signal monitors the temperature of the UVB_Bio sensor
- c(CO2) CO2 concentration of the air, expressed in ppm (parts per million; 1
volume% = 10000 ppm) Concentration is NOT reduced to STP conditions! Sensor: self-built
NDIR double beam sensor based on the GASGARD 3000 OEM board of Edinburgh Sensors (UK,
Edinburgh). Precision = 3%
- WV2 Wind_Direction, Windvane (0 degrees means wind blows from North, 90 degrees
from East ...). Accuracy better than 2 degrees
- Kai Kroneis dew point sensor: voltage of air temperature NTC
Please read
separate file dewpoint.html
- KDe Kroneis dew point sensor: voltage of dew point temperature NTC
Please
read separate file dewpoint.html
Sampling for most sensors : 1 per minute, average stored 1 per hour;
except: RG1, CO2 and WV2: 1 measure per 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 (checked!):
- EXCEL 4.0 (File Open, Text, comma separated)
- QUATTRO 5.0, Windows (Tools, Import, comma and " separated) Attention: Quattro
1.0 for Windows seems to have a bug and can not import these files!
Data-files usually cover a whole month, and contain 744 + 8 = 752 lines for 31-days
months.
The file TEST_94.DAT is a test-file covering part of March_94
Attention: There are several ERROR-FLAGS which may appear BEFORE
- (NOT after!) the data:
- # ... over-run
- $ ... noisy
- % ... outside limits
- & ... overrange
These flags show up mostly on the ESR solar radiation sensor, which gives a slightly
negative voltage at night, instead of zero.
4. HISTORY LOG:
- 11_Mar_94; 09:00 UTC: start of logging
- 18_May_94; 09:00 UTC: installation of aluminium screen to protect datalogger from
direct solar radiation
- 15_Jun_94; 09:00 UTC: installation of an UV_A and UV_B sensor. Due to malfunction
all values from 15_Jun_94 10:00 to 17_Jun_94 09:00 should be discarded. Correct
measurements start at 17_Jun_94 10:00. Please read separate file UV_AB.html
- JULY_94, AUG_94, SEP_94: due to a hardware problem, raingauge reports 0 mm rain,
which was not the case. The global rainfall for these months, as reported by a nearby
weatherstation are:
- JUL_94: total rainfall = 21.4mm
- AUG_94: total rainfall = 16.7mm
- SEP_94: total rainfall = 11.6mm
- 07_Aug_94: The EMP of a nearby lightning stroke killed the serial interface of
the logger. This made communication with a computer impossible, but did not hamper the
normal functioning of the weather- station. All values of August and first part of
September 94 are ok (except rainfall). The logger was out of action from 15_Sep_94 08:00
up to 14_Oct_94 15:00 (repair could not be done more quickly!) Normal operation resumed
the 14th October 1994 at 17:00 UTC
- 25_Jan_95: A period of heavy rainfall and high wind gusts shows that the
rain-gauge measures too high rainfall when wind velocity exceeds about 5 m/s. This is
probably due to wind induced vibrations which provoke a dipping of the water collecting
buckets, even if these are empty or not comppletely filled. The values of 22_Jan_95 16:00
to 23_Jan_95 00:00 and 25_Jan_95 18:00 to 26_Jan_95 00:00 corresponding to high wind
velocities should be discarded. The raingauge-mounting has been modified the 03_Feb_95
10:00 to correct this problem.
- 09_May_95 23:00 UTC: End of logging under previous configuration. Major overhaul
of electrical installation. Added UVB_Bio and CO2 sensors
- 15_May_95 07:00 UTC: Restart with new configuration
- 20_Jun_95 00:00 UTC: CO2 sensor malfunction up to end of month!
- 06_Jul_95 08:00 UTC : Power supply malfunction stops logger. No data available up
to 14_Jul_95 10:00. From this time on 2 new signals from Kroneis dew point sensor
5. DATA FILES:
- MAR94.dat : March 1994; from 11_MAR-94 09:00 UTC to 31_Mar_94 23:00 UTC
- APR94.dat : April 1994; max. et minim. values refer to time shown in the header
- MAY94.dat : May 1994; .... idem ....
- JUN94_1.dat : June 1994; first half of month (01->15 at 08:00) prior to UV sensors
installation
- JUN94_2.dat : June 1994; second half of month; UV sensors installed
- JUL94.dat : July 1994; no rainfall values
- AUG94.dat : August 1994; no rainfall values
- SEP94.dat : September 1994; only values from 01/09/94 00:00 to 15/09/94 07:00 then
logger out of operation until 14/10/94 16:00
- OCT94.dat : October 1994; only values from 14/10/94 17:00 on rainfall sensor problem
corrected
- NOV94.dat : November 1994
- DEC94.dat : December 1994
- 1994.ZIP : all values from 11_Mar_1994 to 31_Dec_1994, together with README.TXT and
UV_AB.TXT files
- JAN95.dat : January 1995 ; please read history log concerning rainfall data
- FEB95.dat : February 1995
- MAR95.dat : March 1995
- APR95.dat : April 1995
- MAY95_1.dat : May 95, 1-->09 at 23:00; previous configuration
- MAY95_2.dat : May 95. 15/05/95 07:00 --> 31/05/95 23:00 new configuration
- JUN95.dat : June 1995
- JUL95_1.dat: 1 to 6 July 1995, 08:00. No data up to 14_Jul_95 10:00
- JUL95_2.dat: 17 July 95 05:43 to 31 July 95 23:45 NO CO2 values; Kroneis Dewpoint sensor
active! (but bad values from 29Jul 21:43 on)
- AUG95.dat: August 1995; no CO2 values, dewpoint-values regrettably bad!
- SEP95.dat: September 1995; partial CO2 values, may be too low. No dew-point-values,
sensor in repair!
- OCT95.dat: October 1995; CO2 values seem to be too low. We wait for a repaired and new
calibrated sensor board. No dew-point-values, sensor still in repair!
- NOV95.dat: NEW REPAIRED and CALIBRATED CO2 sensor starts 16 Nov 95 at 10:00 UTC NEW
REPAIRED and CALIBRATED DEW POINT sensor starts 23 Nov 95 11:00 UTC >LI>DEC95.dat:
December 1995 data. From January 1996 on the history log and other relevant informations
will be included in the monthly data file as a ten line header!