Sensors enable early detection of A2L refrigerant leaks

The PGS6000 sensors accurately detect the refrigerant concentration in the 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.

"Despite being environmentally friendly and energy-efficient, A2L refrigerants are mildly flammable, making them a potential risk if not managed effectively in HVAC/R systems," said Peng Tu, president and CEO of Posifa Technologies. "Early detection of leaks not only prevents the escalation of potential fire hazards, but also protects against possible health risks and saves valuable energy by ensuring efficient operation. With their fast response time, high reliability, and high detection precision, our PGS6000 series sensors are critical components in these systems."

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.