|
26 Dec 18 |
1. We had a complete power loss for nearly 2 days, due to water
drowning a power outlet on the terrace, which tripped the fuse. It
took me quite a moment to find the fault.
2. I installed an Airvisual Pro air monitor, which measures fine
particles (only PM2.5 are shown, but PM10 data are also stored). It
was complicated, as the device has no RJ45 port, but communicates
only through WiFi and needs a DHCP server (which we had not...).I
had to juggle with the few spare IP addresses left in our DMZ zone,
and find a very frugal DHCP server software running on an XPe thin
client. Click on the two pictures below which show the installation
in the Stevenson hut on the terrace, and a screen shot of the data
displayed on the Airvisual cloud. The data are not yet public; after
a longer test they will be freely available as meteoLCD will join
the crowd of Airvisual public sensors.
Picture with the AirvisualPro and the Devolo dlan500 AP below the
transparent cover.
Picture of the data as shown on the (private) website of
Airvisual. |
|
17 Dec 18 |
Oli Frisch, brother of our crew member Benoît Frisch, made with a
drone a very nice nocturnal picture of our lycée and the meteoLCD
terrace's Xmas illumination (the blue broken rectangle on the dark
roof at the right of the picture). Click for a full size view.
On the private side, this is a very sad day for me as my wife
Colette passed away, after loosing a 6 year battle against breast
cancer. She often was very helpful with good counseling regarding
the many computing problems of meteoLCD, and a good listener to my
complaints. I miss her badly. |
|
11 Dec 18 |
Again an interruption of the transfer of our data to the web-site.
Reestablished today at 12:30 UTC |
|
08 Dec 18 |
There was a serious problem with the transfer of our data to our
website. The problem (an ftp blockage on the main Linux computer,
cause unknown) was solved today. There are probably no missing data
in the logger, but a gap in the plots and files on the live-data
page. Please consult the BKP STATION data for missing rain
information. |
|
01 Dec 18 |
Upload of Nov 2018 data
into data archive. |
|
29 Nov 18 |
The interview mentioned below was aired yesterday in the RTL MAGAZIN
emission (at 20:00). Spoken language is Luxembourgish.
Click
here to watch the full video in the RTL archive (start is at
04:18 after the pubs) |
|
22 Nov 18 |
A crew of RTL Teleletzebuerg (Luxembourg's national TV station)
passed at meteoLCD for a short interview on extreme weather events
and climate change. The interview will be aired Wednesday the 28th
November at 20:00 in the "Magazin" emission. |
|
08 Nov 18 |
1. New paper "A
short study in fine particle measurement at meteoLCD by inexpensive
LLS sensors" by the meteoLCD crew and C. Baumann: we compare
the PM10 and PM2.5 measurements of inexpensive LLS sensors with
those of the official Beidweiler station. I think this is the first
paper in Luxembourg on this type of sensors (please
correct if I am
mistaken).
2.There is a problem with the automatical graphs of the total ozone
column...please be patient!....Problem solved (12:00 UTC). |
|
01 Nov 18 |
1.
Upload of Oct 2018 data
into data archive.
2. Click here for the presentations given in Wien :
http://www.uv-index.org/
then ECUVM2018. You will also find a link to "our" video! |
|
30 Oct 18 |
Want to see how the intro-page of meteo.lcd.lu changed over the
years? Click
here to download a slideshow (.exe file) made from the
WaybackMachine captures from 2001 to 2017. |
|
01 Oct 18 |
Upload of Sep 2018 data
into data archive. |
|
29 Sep 18 |
In my ongoing work on fine particles sensors, I assembled a
self-contained PM2.5/PM10 kit using a SDS011 sensor, a SDEV011 debug
board and a IKEA Godmorgon transparent box:
The picture shows the kit in operation; at the right a SNDWAY
instrument measuring only PM2.5.
Here a view on the OLED display on the debug board, with
display-mode "both PM's" choosen (unit is ug/m3). The kit is powered
either by a USB power supply, or a powerpack. A 20000mAh Pilot X7
powerpack gives an autonomy of more than 5 days!
The kit is "display-only" (as the SNDWAY instrument), the measured
data are not stored. |
|
27 Sep 18 |
The last three days give a nice illustration of the inverse
relation-ship between UVI and TOC: the UVB irradiance at ground
level increases when the ozone layer goes thinner:
Read more on this on the blog!
|
|
25 Sep 18 |
1. Stopped WBGT sensor for this year, as strong heat days are
history for this year.
2. Removed Cairsens NO2 sensor, as readings are practically always
very close to zero.
3. The readings of the O3&NO2 Cairsens sensor are taken as [O3];
plots have been adapted. This sensor has been fitted with a new
filter. Be prepared for one or two days of lower readings, as the
filter takes some time to get chemically formed correctly.
5. Installed 3 stations for measuring fine particles: an
AIRVISUAL (by IQair) and a SDS011 station (self-built)
are operating in the Stevenson hut, together with the Vaisala CO2
sensor. A third PM station (Airmaster AM7) is running in the
meteoLCD bureau, on a window sill close to an always open window.
All these fine particle sensors operate offline and store their data
either internally (Airvisual) or on a bespoken Raspberry Pi running
an adapted Python script. It is planned to inspect the data after a
month, a time span long enough to test if the two instruments in the
hut survive outdoor conditions.
The Airvisual sensor is the white box with the large display in the
back, the SDS011's Raspberry Pi has been fitted with an e-ink
display. |
|
07 Sep 18 |
Data transfers to our website stopped the 6th September after 04:00
UTC. Check of all relevant computers and scripts today at 12:15. No
error found. Restarted Lubuntu computer (which makes the heavy
work)...everything seems ok. Strange! |
|
04 Sep 18 |
1. Upload of Aug 2018 data
into data archive.
2. You may have noticed that the
UVI page of the Belgian Institut d'Aeronomie is unavailable
since a couple of weeks. I am not sure what the problem is, but I
know that they had big difficulties to finance this UVI project. The
link at the today_01.html page (live data) is now marked as
unavailable. |
|
22 Aug 18 |
You may have noticed a slight jitter on the barometer readings since
a couple of months; its electronics seem to move to creeping death.
A new (piezometric) barometer has been ordered; as its output is 0.3
to 4.9 VDC a first calibration test was successfully made, and a
second will be done using a voltage divider to bring back the
highest voltage to the data loggers maximum (2000mV). The new
barometer will be installed asap (during the coming weeks..). |
|
05 Aug 18 |
Compare our ground ozone measurements (red curve) with those of the
Environmental Administration done at Beckerich (dark-yellow curve)
during the last 7 heatwave days. Thank you for the thumbs up!
 |
01
Aug
18 |
Upload of the Jul
2018 data into the data archive. |
27
Jul
18 |
meteoLCD's webcam catches Mars and the lunar eclipse in its
final phase. Click for larger original picture (time-stamp in
picture is local summer time = UTC+2)
|
26
Jul
18 |
Today was a very hot day, and the first where our Cairsens NO2
sensor showed a visible NO2 peak (and the corresponding plunge in
ground O3, as NO2 destroys O3):
|
19
Jul
18 |
The high temperatures of the last days evaporated the water
reservoir of the wet-bulb thermometer too fast; I added a third
pumping sequence at 12:00 UTC today. |
05
Jul
18 |
I continue the work on PM (fine particles) measurement, and
assembled a station using the Nova SDS011 sensor (which detects
PM2.5 and PM10) and a Raspberry PI 3 (with an added RTC) to read out
the data and log them to the SD card. The most difficult problem was
getting a correct Python script to work, as practically all examples
found on the Net do not work with the (newer type?) of SDS011.
It seems that my model needs to be launched into measuring mode
(leaving a sleep mode), and this command was probably not needed for
older versions which run continuously when powered up. The script
was modified so that the .csv data file has the date-time as name
and every measurement line begins with a time stamp.
|
02
Jul
18 |
Upload of the Jun
2018 data into the data archive. |
| 28
Jun 18 |
I started a test series to measure fine particles (PM2.5, PM10)
using an el-cheapio Chinese sensor board which holds the particle
sensor (working by laser diffusion), a NDIR CO2 and T and RH
sensors. The board sends its data as a continuous serial stream with
about one line of data every 4.6 seconds. I use a Raspberry PI 2
with an added real-time clock as a datalogger (software is a very
small Python script). A battery powerpack (20000mAh, number in
picture has one zero too many) drives both components, and is itself
continuous recharged by a USB power supply. The system is mounted in
the Stevenson hut where our other gas sensors reside. A first check
was very satisfying, so a longer one has been started today. A
problem with the cheap particle sensors is that the airflow (by a
small fan) is not constant (influenced by wind and pressure
conditions) and that high air humidity tends to give very exaggerate
readings. Our test will show how this applies to the AirMaster AM7
and if it survives outside exposure.
Using the Powerpack protects the assembly against power outages
and allows to transport the running equipment (the Powerpack can
drive it for 24 hours before going flat).
|
| 03
Jun 18 |
Upload of the May
2018 data into the data archive. |
| 01 Jun 18 |
Following a heavy storm last night, my Internet access is down.
Upload of last month data will be made asap. |
| 08
May 18 |
Raoul Tholl brought the WBGT system back to correct function (13:00
UTC). We will keep an eye on it.... |
| 07
May 18 |
There is a problem with the WBGT system: the wetbulb thermometer is
dry, probably due to a fault with the pumping system which should
keep the thermometer wet. As a consequence the calculated
heat-stress is not correct. |
| 04
May 18 |
1. There was an error in the first plot of air temperatures
(conflicting left and right y-axis). This has been corrected (with
some efforts as a wrong time format in the "previous days" graph of
air temperature was missed). Thx to N. Harpes for pointing to this
error!
2. This is the first day where our Cairsens NO2 sensors shows NO2
values different from zero. The peak NO2 at 07:00 about 18 ug/m3
seems plausible. |
| 01 May 18 |
Upload of the April
2018 data into the data archive. |
| 28
Apr 18 |
1. The display of the WBGT heat stress as been restarted at
16:45, the sensors (actually the pump wetting the humid Pt100) this
morning at ~08:00 UTC. Click here
for a picture that shows how efficient humidifying is to lower
temperature (see the split of blue and green lines after 08:00).
2. A check of the CAIRSENS NO2 sensors shows practically 0 ppbv
concentration (lower than the limit of detection). So the quasi zero
display of NO2 does not seem a fluke: our NO2 values are very small
at Diekirch!. |
| 19
Apr 18 |
1. There was an error with the "previous days" graphs of O3 and NO2;
now ok (09:00 UTC)
2. The CAIRSENS NO2 sensor has a LOD (Limit Of Detection) of about
10 ppb ( = 20 ug/m3). So do not be surprised by quasi zero readings,
as NO2 levels usually are low at Diekirch. You may read this
test report. |
| 18
Apr 18 |
Both CAIRSENS sensors are now on-line, using analog voltage data
transmission which does not show the nasty electrical ground
problem. The live page today_01.html has been slightly changed: the
"AIR QUALITY" plots now show ground ozone (O3) calculated as the
difference between the combined O3&NO2 sensor and the new NO2
only sensor; on the same graph the plot of NO2 will also be
shown. All units are ug/m3, and the conversion factor between
ppb (as given by the Cairsens sensors) and ug/m3 is 2 for both
sensors.
Please be patient if some glitches remain...The combined O3&NO2
"AQ" data are in channel 16, the new NO2 data in channel 17 of the
logger files (as today.dat). As ch.17 had no sensor during the first
10 hours of the day, the graphs show impossible values for this time
span (due to Gnuplot's autoscale function).
Click here for a picture.
|
| 17
Apr 18 |
I installed this morning our second CAIRSENS sensor, the NO2 model
(delivers into channel 17 of the logger). From a hardware point of
view, everything runs smoothly, but there is a nasty probleme with
the analog signals going into the logger. Probably again a common
ground problem, either caused by a dual-port USB power supply or the
common ground in the two 4-20mA loops. I will check this asap, and
possibly try a classical voltage signal output for both sensors,
instead of the4-20mA loop. Please ignore glitches and other
disturbances in the graphs. |
| 01 Apr 18 |
Upload of the March 2018
data into the data archive. |
| 30
Mar 18 |
A new paper by Yuan et al. citing meteoLCD authors F. Massen and
E-G. Beck has been published in Atmospheric Measurement Techniques.
See here
or look at our "papers" website
under "foreign papers". |
| 01 Mar 18 |
1. Upload of the February 2018
data into the data archive.
Attention: there are no data from 26/02 08:00 to 27/02 08:30, due to
the logger breakdown. This is a very rare event in the more than 20
years of meteoLCD, but alas not an impossible one!
2. The plots of Air Quality now show in the title "good if <
200). This qualifier corresponds to the UK norm of combined O3 and
NO2 concentration; if that number is below 200 ug/m3, the situation
corresponds to the 2nd level of the "GOOD" (=green) category, which
holds 3 levels. |
| 27
Feb 18 |
1. The datalogger computer was unable to load it's system (XPe), no
obvious cause found. Restarted at 07:28 UTC today.
2. There is a second much more severe problem: the datalogger has
corrupted readings, probably caused by my yesterday tests with
reading dual analog signals (voltage and intensity) of the Cairsens
O3&NO2 into the logger (problem of channel overload from
inexistent galvanic separation, obscure common ground problem....).
3. I downloaded all data from the logger, emptied memory,
re-installed configuration and programmed to restart logging at
09:00. The first correct data (graphs and numbers) should be
available at 09:45. |
| 26
Feb 18 |
There is a breakdown of our datalogger computer, since this morning
around 07:30 UTC. Will look at the problem tomorrow morning...Sorry! |
| 19
Feb 18 |
The meteoLCD crew has written a short paper comparing our 2017 total
ozone column measurements with those made at the RMI, Uccle (close
to Brussels). Uccle is a world famous research facility for TOC
measurements, and has one of the longest data series available. Our
Diekirch measurements made with vastly less expensive instruments
are quite satisfying. Read the paper
here. |
| 01 Feb 18 |
1. Upload of January 2018 data
into data archive. Please read metadata (file header) very
carefully!
2. Attention: this is the last month with [O3] readings from the
O341M sensor, which will be shut down now. The overlap with
simultaneous measurements by the CAIRSENS O3&NO2 allows a
comparison of the two measurement series, and most important, about
their temporal synchronicity. A quick check shows a very satisfying
behaviour of the CAIRSENS device, so that we plan to add a second
CAIRSENS measuring only NO2, which would give [O3] by simple
difference between the two CAIRSENS readings.
A real serious investigation on the CAIRSENS sensor can be found
here (with highlighting added). |
| 11
Jan 18 |
1. Work on the "trends"
section finished. Some future editing is probable, as some datasets
for comparison (like Uccle's TOC at WOUDC) are still uncomplete.
2. A first quick comparison of the measurements of our new CAIRSENS
Air Quality sensor and the old ozone sensor shows a quite satisfying
correlation. |
| 04
Jan 18 |
Work on the "trends"
section has started. 7 parameters out of 13 have been updated. This
is not a fast and quick automatically done procedure, but remains
tedious work, so be patient waiting for the final update. |
| 03
Jan 18 |
Installation of the new CAIRSENS
O3&NO2 mini-sensor (09:30)
This electrochemical (amperometric) sensor measures the combined
O3 and NO2 concentration, which we call AQ (for Air
Quality). The new measurements are on channel 16 (the
former NOx channel). Channel 17 (former NO) should be ignored!
Picture shows our Stevenson hut with the Vaisala CO2 and the
Cairsens O3&NO2 sensors (click for full size).
Using this sensor is sort of an experience. Only time will tell
if it lives up to its promises (no calibration needed, minimal
maintenance, acceptable precision).
The graphs of today will be a bit messy!
The purchase of the new sensor has been financed by our sponsor
AALCD (Amicale des Anciens du Lycée Classique Diekirch).
|
| 02
Jan 18 |
Upload into data archive of :
1. yearly Excel file with 2017 measurements and elementary
statistics : 2017_only.xls
2. summary Excel file with statistics 1998-2017:
meteoLCDstats_1998_2017.xls
3. Corrected/edited the "monthlys" worksheet of the 2016_only.xls
file.
4. NOx/NO2 sensor from Environnement SA (AC31M) definitively shut
off.
This is the end of our traditional atmospheric gas measurements
using big and expensive equipement. The O341M sensor for ground
ozone will continue for a couple of weeks to allow comparison with
the new equipment, before also going into retirement! |
| 01 Jan 18 |
1. The usual dogs-dinner in the 7days plot due to Gnuplot problems
with handling previous and new year (the logger files do not contain
the year number). This will be self healing in the the next 7 days.
2. Upload dec17.dat and 2017.zip
(= all 2017 .dat files concatenated with headers, and zipped) into
data archive.
|
