Posifa A2L Refrigerant Leak Sensors Receive UL Recognition

­Posifa Technologies announced that its PGS6032 and PGS6454 MEMS A2L refrigerant leak sensors have been recognized by UL Solutions. This distinction verifies that the devices meet the safety and performance requirements for refrigerant detection systems outlined in Annex LL of UL 60335-2-40:2022, fourth edition, which apply to household and similar electrical appliances, including heat pumps, air conditioners, and dehumidifiers.

“Achieving UL recognition for our PGS6032 and PGS6454 refrigerant leak sensors represents a critical milestone for Posifa,” said Peng Tu, president and CEO of Posifa Technologies. “This approval underscores our commitment to meeting the highest safety and performance standards for refrigerant detection systems. It builds on our previous successes with certifications from agencies like Intertek and further solidifies our stature and credibility in the market.”

Posifa’s PGS6000 series sensors accurately detect A2L refrigerant concentration in air by measuring the change in thermal conductivity of the gas mixture inside the cabinet. This technology increases safety and efficiency by enabling early detection of leaks while providing long-term reliability of 15 years or more in harsh environments. The PGS6000 series uses Posifa’s second-generation MEMS thermal conductivity sensing element. It features a patented heat transfer cavity that achieves highly sensitive and repeatable thermal conductivity measurement by eliminating possible occurrences of natural convection inside the cavity. As thermal conductivity measurement is accomplished completely inside the sensor chip, maximum miniaturization can be realized at the device level — a critical capability for HVAC equipment manufacturers who must retrofit the sensors into existing designs.

The detectors are designed with a relative humidity sensor and a barometric pressure sensor. This strategic incorporation enables the detectors to compensate for thermal conductivity changes influenced by variations in humidity and barometric pressure, enhancing the accuracy of A2L refrigerant concentration measurement. The PGS6000 series detects R32 and R454B refrigerants, and supports RS485 MODBUS RTU output.

Key features of the PGS6000 series include a fast response time of < 250 ms and compensation for humidity and pressure, ensuring accurate functioning in harsh environments. Notably, the sensor has no lamps or delicate optical paths to break and is non-reactive to “poisons” or contaminants, guaranteeing long-term stability and reliable performance.