The Guardian is constructed from high-quality ASA plastic with low thermal conductivity and a gloss white finish in selective areas to lower emissivity with an IP rating of IP53. The Guardian is filled with foam to provide additional thermal insulation. Additionally, a quantum sensor is mounted on the top of the shield to measure PAR (
SM-500) or ePAR (
SM-600). The internal airway utilizes a small venturi constriction to maximize airflow efficiency over the thermistor, which minimizes the thermal boundary layer’s influence on temperature measurements. Simultaneously, a separate module used to measure CO
2, humidity, and pressure is aspirated by a passive, low velocity airstream using a “fluid entrainment” principle.
