Super User OEM Probe Only Thermal Sensors Custom Packaged Thermal Mass Flow Sensors - OEM Probe Only Thermal Sensors Sierra Instruments' OEM probe only thermal sensors can be integrated into your end product package as a thermal mass flow sensor probe or probe / electronics set. The sensors used in our 640S and 620S thermal mass flowmeters are often customized for customers needing just a raw sensor mass flow output signal or as a raw sensor electronics set. The sensors can be calibrated to your specifications. Mass flow sensor probes to fit your OEM needs Wide flow range from 0 to 20,000 sfpm Increase flexibility with low pressure drop Turndown: 1000:1 Patented DrySense™ sensor Backed by lifetime sensor warranty OEM Probe suitable applications Air volume flow metering Compressed air flow Aeration basin air flow Combustion air flow Natural gas fuel flow Custody transfer Stack gas emissions flow monitoring OEM Probe Only Thermal Sensor options Wide range of process connections High temperature option 750°F (400°C) Self-cleaning purge for dirty flow environments Axial probe design for dirty flow environments Longer probe lengths Multipoint flow averaging arrays for very large ducts