Topic: Barani: too good to be true...

[Jasper3012]

Here is the sheet from @gvdb1111’s comparison, the environment is exactly the same as at my setup, open and green. The sheet has values from the Stevenson screen, MS Pro with temp/hum probe, MS Pro with NTC sensor and Barani MeteoHelix. Make of it what you want but in my opinion, if this trend in the data continues, the MS Pro can 100% be used as a reference in long term climate stats in the Belgian climate.


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[Jasper3012]

Pic of my setup again:

Curious, why are the two solar panels not aligned? If I see what little shadowing there is, looks like the Davis is facing east, no? If so, obviously less fan speed average from less direct sun.

The Davis panel is facing south, the other one west, because we couldn’t put the wooden pole in a different orientation. I only have a small strip where I can put my stations there because there is tractors cutting the grass every few weeks and I obviously don’t want my stations getting hit by a tractor.

[CW2274]

Pic of my setup again:

Curious, why are the two solar panels not aligned? If I see what little shadowing there is, looks like the Davis is facing east, no? If so, obviously less fan speed average from less direct sun.

The Davis panel is facing south, the other one west, because we couldn’t put the wooden pole in a different orientation. I only have a small strip where I can put my stations there because there is tractors cutting the grass every few weeks and I obviously don’t want my stations getting hit by a tractor.

Figures I'd be 90 degrees out. 

[mauro63]

Here is the sheet from @gvdb1111’s comparison, the environment is exactly the same as at my setup, open and green. The sheet has values from the Stevenson screen, MS Pro with temp/hum probe, MS Pro with NTC sensor and Barani MeteoHelix. Make of it what you want but in my opinion, if this trend in the data continues, the MS Pro can 100% be used as a reference in long term climate stats in the Belgian climate.


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Totally agree 

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M.

[gvdb1111]

Here is the sheet from @gvdb1111’s comparison, the environment is exactly the same as at my setup, open and green. The sheet has values from the Stevenson screen, MS Pro with temp/hum probe, MS Pro with NTC sensor and Barani MeteoHelix. Make of it what you want but in my opinion, if this trend in the data continues, the MS Pro can 100% be used as a reference in long term climate stats in the Belgian climate.


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I would like to add to the sheet Jasper posted:
- test site is the synoptic station from the Royal Meteorological Institute of Belgium, station 06472 (WMO Class 2)
- this is the same test site where Barani is referring to for the test of their MS PRo by the RMI some years ago
- shield 1 is the MS PRo with a (calibrated) SHT35 inside as probe, but with a sintered metal filter which has a time constant of ~1.5 to 2min at 1m/s windspeed
- shield 2 is also MS PRo with a NTC probe containing a (calibrated) thermistor 10K3A1A sensor (highest accuracy available in this series)
- shield 3 is a Barani Meteohelix, about 2 years old

[Meteorology fan]

A windy day and these results from today on Sensirion SHT35 without filters and PT1000 4-wire. Wind gusts reached 27-30 km/h.

[Jasper3012]

Rather calm day here but with a fair bit of cloud, 17.3C on the FARS and 16.9C on the MS Pro as the maxes. The max occurred during a short peak so in this case, I consider it likely at least 0.1C or 0.2C is due to the quicker response time, rather than an error. Difficult to know exactly, of course.

[Jasper3012]

Mowed the grass and installed a top plate above the FARS but the ~0.3C difference seems to be maintained.

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[Dador]

Mowed the grass and installed a top plate above the FARS but the ~0.3C difference seems to be maintained.

This constant difference seems a bit suspicious. Since you have the same sensors in Barani and Davis, it may be worth swapping them, if possible, and checking if the sensor is not lying?

[tobyportugal]

Mowed the grass and installed a top plate above the FARS but the ~0.3C difference seems to be maintained.

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If the aim is to break the sun's rays, I'd have fitted it the other way round.
I think that the descending edge is a great risk of overheating in zero wind, as the air is trapped.

[CW2274]

Mowed the grass and installed a top plate above the FARS but the ~0.3C difference seems to be maintained.

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If the aim is to break the sun's rays, I'd have fitted it the other way round.
I think that the descending edge is a great risk of overheating in zero wind, as the air is trapped.

I, ummmm... Never mind.

Both ideas are irrelevant. The shield obviously does its job as designed without help. If you must, look elsewhere. This ain't it.

[tobyportugal]

@cw2274  Probably my very bad English... this kind of assembly is not part of my investigations or my ideas!
Anyone who wants to do this kind of test should limit the risk of air cushioning as much as possible, as stagnant air becomes a positive or negative thermal insulator.
Edit : for cw2274  writing with a tablet isn't my thing 

[Meteorology fan]

Jasper3012 - If you want to see if the Davis FARS24H actually overheats, you should compare it to another aspiration cover from companies like Met One and Apogee. Looking at it objectively, those tall grasses can modify that microclimate and heat up in the summer and the aspiration shield sucks it up.

[CW2274]

@cw2274  Probably my very bad English... this kind of assembly is not part of my investigations or my ideas!
Anyone who wants to do this kind of test should limit the risk of air cushioning as much as possible, as stagnant air becomes a positive or negative thermal insulator.
Edit : for cw2274  writing with a tablet isn't my thing 

Hello Mauro,
I think that snapshots are invaluable information, provided of course that the installation complies with a minimum of rigour.
You know my (imperfect) installation and my particular climate.
The snapshots make it possible (sometimes) to distinguish between the 'installation', 'climate' and 'shelter' factors, because all my sensors are strictly identical.
Remember Antonio's peak in a single shelter at the same times for a few days in May 2022.
We analysed the video images, swapped the shelters and neither you nor Antonio nor anyone else could come up with an explanation.
Someone present here would have shouted out loud that this shelter is a "piece of shit".
This phenomenon reappeared a year later in more or less the same conditions, so with hindsight we can reasonably look for an external, non-climatic explanation.
In all the information that you can read on the left and right, it's mainly the pseudo 'PRO' sensors or the very complicated shelters that are problematic. To operate a TS correctly the bill is at least €1000.
Well, I'm going back to my Belgian dreariness.

Will the real 'tobyportugal' please stand up! 

[Jasper3012]

I’ll probably just remove the top plate as it didn’t seem to help anyway yesterday. The sensors aren’t the issue, they were calibrated only a month or 2 ago and they match up perfectly during windy and cloudy weather at night. Other than that, I think I measured what @meteorology fan has been mentioning for the first time yesterday evening, the sea breeze died off at around 9 PM and with a low sun angle, the Barani had a significant error: the min during a 10-min interval was 0.8C warmer than the min on the FARS for that same interval (14.9C vs 14.1C) and the max/avg temp also had a significant error. The whole thing lasted “only” 50 min and it did not affect the min/max of the day but something was definitely off with the MS Pro for that 50-min period.

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[Meteorology fan]

@Jasper3012 - Yes, it is probably this phenomenon at low sun angle and low wind that the Barani Meteoshield Pro III suffers from. Watch carefully for readings about sunrise and sunset. In winter and autumn in Poland, this phenomenon can be observed throughout the day, projecting maximum daily temperatures. Independent of the sensor, because and on PT1000/PT100 we saw it and SHT35 without filter and with filters.

[Jasper3012]

How it's looking after 10 days.

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[hmderek]

Pic of my setup again:

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Oeh, like that spot.

[Jasper3012]

Think I can already make a few statements with a decent degree of confidence, even after a rather short period of testing… What I’ve been finding also matches up with another wx enthusiast I know that also owns both a Barani MS Pro and a Davis FARS, so that adds further confidence.

1) MS Pro generally performs slightly better during high angle sunshine and with some sort of breeze (0.2-0.4C cooler)
2) FARS performs slightly better during calm and clear nighttime wx (0.1-0.3C cooler)
3) FARS can perform significantly better during low angle sunshine and low wind (up to 1C, possibly more)
4) Difference is minimal during cloudy weather, no matter the wind and time of day

I’d say that for a temperate climate with frequent wind and cloud, there is very little benefit to using a FARS over a MS Pro and you won’t see any difference in long term (monthly and annual for example) averages. For tropical climates, I also believe the MS Pro is a great choice, as it performs very well during high angle sunshine and weak to strong wind. For continental climates with a long duration of low sun angle and weak wind, you may be better off with a FARS.

[Meteorology fan]

Barani has the advantage of being unmanned and most of the time there are similar/analogous maxima and minima to the WMO Screnn. However, in autumn and winter, disturbing overestimations of measured air temperature can occur most days of the year, forecasting daily/weekly and monthly averages and maxima. Certainly, there will be more such days in Poland than in Belgium.

If you want to check other actual coverages, Met One and Apogee are worth trying.

Response time at night in low wind conditions also in favor of the Davis FARS24H and Apogee TS100 over the Barani Meteoshield Pro III.

[Jasper3012]

“Disturbing overestimations most days” is again highly exaggerated, most winter days have very little sunshine anyway, so there won’t be an error most of the time. Very low sun angle (the sun was nearly at the horizon when I got the significant error a few days ago) and little wind is a very rare combination here in winter.

[Jasper3012]

Update! Barani doing very well so far. The weather has been dreadful here, so the conditions have favoured the Barani, but still.

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[Meteorology fan]

In windy climates, the Barani will perform well. However, where the wind is weak, it will not replace the Stevenson Screnn and the Apogee TS100 and Met One class aspiration shields and Davis FARS24H.

Barani's shield can hardly be considered a reference and cannot be a benchmark for other shields and Stevenson Screnn. Better option than Barani Gen III

https://metspec.net/instrument-shelters/

[Jasper3012]

You’ve repeated the same exact argument a million times now but the data from @gvdb1111’s comparison and mine tells a very different story, with in fact a better performance from the MS Pro compared to a Stevenson screen and Davis FARS.

[Meteorology fan]

It is no more efficient than a full-size Stevenson Screnn. This is acutely untrue what you said. Such a Metspec cage is much better and does not suffer from those defects that are serious in Ms Pro. Do you consider something that can show 1.5-2 degrees more than the normal air temperature as a reference and top measurement? For meteorological services for the main measurement the Barani shield is not suitable, it can be as a backup.

If it were otherwise, Barani all over Europe would have its casing on the main measurement at weather bureau stations. The performance of these Stevenson Screnn will generally be better than Meteoshield Pro in harsh conditions.

https://www.metcheck.co.uk/collections/metspec/products/metspec-m12-excel-acrylic-stevenson-screen

https://www.weathershop.co.uk/metspec-clips-accessory