The DeltaCal® is a simple-to-use, NIST Traceable Standard for volumetric air flow, barometric pressure, and ambient temperature. The deltaCal is a venturi based system with built-in compensation for changes in ambient temperature and pressure. Total flow range of 2 to 19.5 LPM. DC100 Model provides flow range of 10 – 60 LPM. DC200 Model provides flow range of 0.3-3.5 LPM. NIST-traceable accuracy ≤ 1% of flow reading.