NEWS

These are the news starting 01 Jan 2021
Click here for the news of the previous years.

15
Oct
21
The history of over 25 years operation of meteoLCD has been published in the 2021 year book of the Lycée classique Diekirch.
Written by Francis Massen in French, it is titled "meteoLCD: 25 ans  de mesures et de présence climatologiques". Click on the title to download a PDF version.
06
Oct
21
The WBGT sensor has been shut down (the Wet Bulb thermometer will not have its cooling water renewed); clicking on the icons will nevertheless show all 3 signals, but please remember that the Wet Bulb readings correspond to a "normal" air-thermometer readings.
02
Oct
21
Uploaded September 2021 data (sep21.dat) into data archive.
01
Sep
21
Uploaded August 2021 data (aug21.dat) into data archive.
04
Aug
21
The lightning computer is out of order. Not sure if this can be repaired asap. Please use link to excellent site blitzortung.org as a replacement.
01
Aug
21
Uploaded July 2021 data (jul21.dat) into data archive.
24
Jul
21
From the 17th to 19th July we had a problem with the Globe Temperature sensor of the WBGT assembly. Raoul Tholl looked after the problem, which was a contact problem in a switch box. Things are back to normal from the 20th July on.
06
Jul
21
A class of 16 older students (second last class of the lycée LTPS Ettelbruck) visited with its professor Raoul Tholl meteoLCD (and the Computarium). We made a guided tour over the terrace, explaining the different instruments, showing the computers driving the station and gave some thoughts on the question of climate change problem.
01
Jul
21
Uploaded June 2021 data (jun21.dat) into data archive.
23
Jun
21
Yesterday there was a precipitation event: our usual rain sensor missed several mm (compare its reading with those of the Davis backup station). The culprit was not bird droppings (my wire mesh seems to deter!) but some dust and a too narrow tube outlet above the tipping bucket. I slightly enlarged the opening with a sturdy Teflon tube... let's hope  this will cure the problem. The rainfall shown today (before 11:00 UTC is more or less the quantity missed yesterday, so the monthly total should approx. be correct.
20
Jun
21
Yesterday (19th June) we had the first serious thunderstorm starting about 18:00 UTC. Click on the picture for an animation showing a couple of screen-shots starting 18:39 and ending after 20:59. The bluish crosses are the new impacts, and the yellow dots the previous ones (with some noise). Clearly the storm moved from south-West to North-East. So the reinstalled old antenna seems to be ok for the moment.

Click also on the following picture that shows nicely the effect of radon washout (and peak in air radioactivity) caused by the thunderstorm rainfall (about 12mm in 3 hours):

15
Jun
21
Renewed wick of the WBGT sensor; sprayed black globe with black color, added one more distilled water pumping at 16:00 UTC to avoid wick drying during the late afternoon hours. Checks show that 3 daily pumping sequences each of 1 minute is sufficient (08:00, 12:00, 16:00 UTC). This gives an autonomy of more than 2 months per canister of demineralized water.
13
Jun
21
I spent my Sunday afternoon downloading the Haenni Solar sunshine-hours data, and tried to find the fault of the Boltek lightning detection system. Finally the culprit is the latest (active) antenna which was installed  last  year, and which now was stone-dead. I reinstalled the previous one, and checked if it detected electromagnetic noise (using an old computer). This older antenna nicely showed up this noise (what the other didn't do). So we just have to wait for a good thunderstorm... I am musing on replacing the antique Boltek Stormtracker system (which is built on a PCI-card) with the latest LD-350 model (USB model). It's a bit pricey, so we must see if our remaining budget can eventually tackle this.
09
Jun
21
1. My colleague Frank Thillen gave me a piece of INOX wiremesh (from his bee-hives), and I added sort of a bird-deterrent to the rain-gauge. If the future shows that this mesh blocks too much of the precipitation, it is easy to shorten and/or reduce the number of spikes. Let's hope that the birds will be scared!

2. The lightning sensor is out of order. Reason unknown for the moment.

08
Jun
21
1. The "old" Cairsens O3&NO2 sensor has been removed and replaced by a new model, which will be good for a year without calibration. The conversion factor in the logger has been reset to the default; a comparison with the Beckerich station over the next weeks will tell if these defaults can be kept or will have to be modified. Start of the new sensor is today 07:00 UTC. I want to recall that we take the combined readings of O3&NO2 as "pure" O3, as the NO2 levels are nearly always below the detection limit of 40 ug/m3 (there is no pure O3 sensor available in the Cairsens line). The O3 calibration certificate of the new sensor shows a very good linearity with 4 ppb Ref <--> 6.67 ppb Cairsens and 180 ppb Ref <--> 182.98 ppb Cairsens (Ref is the O342M 27 snesor). We use the conversion factor of 1 ppb = 2 ug/m3.

2. The Rain sensor was again blocked by bird droppings; I allowed the accumulated rain drip down, so to have at least an approximate correct total for the last week. But pay attention to the fact that the shon precipitation today is an artefact. Best is to look the readings of the Davis Backup station for these missing days.

3. The SPM10  Kipp&Zonen solar sensor (ch.6) has since a few month some humidity droplets under the outer quartz dome. I opened the sensor cleaned this, but there remains also a slight condensation on the inner dome, which I am unable to open. I should compare the readings of this sensor with those of the old CM21 (ch.23) which is still active; it has a dessicant capsule I replaced today.

01
Jun
21
Uploaded May 2021 data (may21.dat) into data archive.
18
May
21
The Linux computer doing the full work stopped working today at 00:30, for reasons unknown. Relaunched at 14:00 UTC.
11
May
21
The WBGT (heat-stress) equipment has been reactivated for this year. Well, the temperatures are still far from being stressful, but who knows, the meteorological situation may change fast!
01
May
21
 Uploaded April 2021 data (apr21.dat) into data archive.
29
Apr
21
New article in the BLOG on computing the Radiation Amplification Factor RAF from 5 cloudless days in April 2021. No great changes from previously found values!
02
Apr
21
1. Uploaded March 2021 data (mar21.dat) into data archive.
2. There was still a problem with the calibration function of the CAIRSENS. This has been corrected and display of readings will resume soon this afternoon.
31
Mar
21
I am not too happy with our ground-ozone measurements made by the Cairsens instrument. From start on there was a big difference with our "reference" station of Beckerich, and at least during 2021 a huge bias showed up in the calibration curve: the Cairsens readings have a negative bias and a too small amplitude.

The following graph shows the daily averages fro 1 to 27 March 2021. It suggests to apply a multiplier of 1.4 and an offset of 23 to the readings stored.

The 1th July 2020 we introduced the following formula to adjust the Cairsens readings to Beckerich:

Diekirch_adj. = Diekirch/0.9311 - 36.309, which is programmed into the datalogger.

This will be changed tomorrow to Diekirch_adj. = Diekirch/0.6651 - 27.8

The Cairsens sensor in activity is the second in our line, and I was very satisfied with the first. The second, despite a good calibration certificate, did not behave well. It will be replaced in May 2021.

12
Mar
21
Ok, all is well now with the Airvisual Pro and the PM 2.5 data on the cloud!
11
Mar
21
The problem with the data transmission of the Airvisual PM sensor is still not solved; the data are correctly transmitted into my (private) dashboard on the iQAIR cloud, but not updated on the public website. This could be a configuration problem of iQAIR, with a glitch made when changing form one device to another.
05
Mar
21
1. Filter of Cairsens O3 sensor replaced; this explains the sharp dip around 08:00 UTC. Readings have a bias of about 10 -ug/m3 w.r. to Beckerich, so are distinctly to low. I will wait for a week for the new filter to become fully active, and will redo a calibration control with Beckerich thereafter.
2. The old Airvisual PM sensor (Air Quality) has been replaced after 2.5 years of activity by a new one, same model (called METEOLCD2). iQAIR has forgooten to think that a replacement is an option, so I have to go to the full sequence for bringing the new model back into the cloud. So the new data will not be avaible for some time on the live-data link. I wrote to iQAIR about this, possibly this will make this a bit speedier!
02
Mar
21
Upload February 2021 data (feb21.dat) to archive.
05
Feb
21
Update of "Trends" chapter to include 2020 data finished.
01
Feb
21
Upload January 2021 data (jan21.dat) to archive.

 

06
Jan
21
I started updating the "Trends" section. This is work in progress, and demands a lot of time.. so please be patient!
03
Jan
21
1. The big Excel file (2020_only.xls) has been uploaded into the data archive. It holds all readings and daily's and monthly's averages, together with several results from the Findel meteo station (Metolux).
Yes I know that .xls is passé, but I remain faithful (most of the time) to the 2003 Excel version, and all the newer .xlsx versions can read these vintage files.

2. The 7days graphs are still bad... best is to be patient until next Friday.

01
Jan
21
1. Our old faithful Delta_T datalogger does not store the year count in its data-time column, so there usually is a mess with the Gnuplot 7-days plots during the first week. I intervened manually to cut off the last December 2020 days; this means that the 7 days plot wil first show only 1, than 2, 3..., up to 7 days during the ongoing week. This hopefully will get rid of the usual dogs-dinner plots  for the next days...

2. Upload December 2020 data (dec20.dat) into data archive
 

 

 

 


Back Home