AUSTIN, Texas — DunAn Microstaq Inc. (DMQ), a MEMS technology company, now offers a Digital Pressure Temperature Sensor (DPTS) to measure subcooling for HVACR applications. Samples will be available for evaluation in March 2023.

The DPTS is a self-contained device that measures pressure, temperature, and calculates subcooling based on refrigerant type. It is compatible with all ASHRAE safety groups A1, A2, and A2L refrigerants. The latest generation DPTS can read maximum pressure between 500-700 psi.

The DPTS is available as a superheat sensor as well. In a HVACR system, two DPTS sensors can be used to measure superheat and subcooling. Superheat measurements monitor the efficiency of the HVACR system and can be used as a safety sensor to protect the compressor from liquid flooding. Subcooling measurements monitor the refrigerant charge level and control the high-pressure flow control valve to maintain the condenser mass flow rate for optimum performance (DMQ Patent No. 10,648,719).

The end user communicates with DPTS devices via the RS485 communication bus using the MODBUS RTU communication protocol. The DPTS is installed on a ¼-inch SAE 45-degree flare male fitting for pressure measurements and a temperature sensor from the DPTS wiring harness is installed at the exit of the evaporator for superheat measurement or at the exit of the condenser for subcooling measurement. The end user may utilize both superheat and subcooling readings as input to trigger a programmable output to electrical equipment such as valves, actuators, or compressor contactors via solid-state relays.

The DPTS superheat and subcooling sensors can be used for monitoring efficient operation of the HVACR system, predicting equipment failure, real-time refrigerant charge monitoring for refrigerant leak detection over time, and efficiently managing system refrigerant charge. DMQ’s DPTS components are the future for real-time refrigerant charge management/monitoring to protect both the natural environment and HVACR systems. For more information, visit

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