Here the risk that this was the case is low. The Apogee TS-100 is slightly higher than the Barani Meteoshield Pro III. It was operated at minimum speed to avoid wet-bulb effects on high and radiation nights.
The difference of -0.37°C between the Apogee TS-100 and the Barani Meteoshield Pro III is too small to indicate a wet-bulb effect. If the Apogee TS-100 were affected, the temperature drop would be much greater, potentially by as much as several degrees, especially with high humidity.
Why is this not a wet thermometer effect?
No excessive temperature difference - Apogee TS-100 recorded a minimum temperature only 0.37°C lower than Barani, suggesting better air exchange rather than an evaporative cooling phenomenon.
Radiation conditions - on windless nights with strong ground heat radiation, the air near the surface cools intensely, and a shield with inferior ventilation (Barani) may not be able to keep up with this decline. Apogee, even at minimum FARS, could better track the actual temperature.
Humidity does not indicate evaporation - previous data shows that humidity was high at night, but not so extreme that the wet thermometer effect could play a key role.
What was the reason for the difference?
The Barani had stagnant air and did not reflect the temperature drop as well.
The Apogee TS-100 better reflected the actual temperature, rather than the effect of a wet thermometer, thanks to minimal ventilation.
Bottom line: it's more a problem with the air exchange in the Barani than the effect of a wet thermometer in the Apogee.
Based on these minimum temperatures:
Apogee TS-100 (PT1000) → -13.64°C
Barani Meteoshield Pro III (PT1000) → -13.27°C
What this means.
The Apogee TS-100 recorded a lower minimum temperature, suggesting that it better reflected the actual air temperature in radiative cooling conditions.
The Barani Meteoshield Pro III overestimated the minimum temperature by 0.37°C, which supports the thesis of the problem of stagnant air and its insufficient replacement in the absence of wind.
Which shield was more accurate?
The Apogee TS-100 better reproduced the actual minimum temperature, which means that its design (FARS at minimum speed) provided better air exchange and no heat accumulation.
Barani overestimated the temperature, indicating that the shield did not provide adequate ventilation for the sensor under conditions of a windless radiation night.
This is further evidence that under calm radiation conditions the Barani shield may tend to overestimate the minimum temperature compared to the ventilated Apogee TS-100 shield.
