QUESTION: Can the Rotronic MP100, MP400 and HydroClip2 HC2 fit the MeteoShield® Pro helical radiation shield?

ANSWER: YES, the Ø15 mm Rotronic HydroClip2 HC2 fits perfectly inside the MeteoShield® Pro with the standard M25 sensor clamp. The Rotronic MP100, MP400 have a diameter of Ø25 mm and require the special order M32 sensor clamp option for sensors up to Ø26mm. Please contact us.

While the MeteoShield® Pro is the highest precision solar radiation shield for meteorology in the marketplace, the Rotronic probes are some of the highest quality combined temperature and humidity sensors on the market. On the other hand, to achieve laboratory precision in all-weather and the outdoors, they require a high-quality meteorological solar radiation screen, which Rotronic does not offer.

Basic physics of achievable precision in atmospheric air temperature measurement follow: Temperature sensor can only accurately measure air conditions that exist inside a radiation shield. Thus the solar radiation shield dictates the maximum achievable accuracy of the temperature sensor and radiation shield combination.

Practical explanations follow:

• During daytime, minimizing errors from solar heating, reflected and radiated light and heat from the ground is essential.

• During rain, protection from water spray of dispersed rain droplets and water spray due to wind is essential to minimize evaporation cooling errors and latent heat effects of wet sensors.

• At night, ample airflow to the sensor is necessary to avoid under-cooling errors when skies are clear and also to prevent heating errors due to the warmer shield radiating heat onto the sensor as the air cools throughout the night.