Accuracy : Air: ± 1% of reading ± 0.5% of full scale. Other Gases: ± 1.5% of reading ± 0.5% of full scale.Maximum range: 15-15,000 SFPM (0.07-71 NMPS)Minimum range: 15-1,000 SFPM (0.07-4.7 NMPS) unobstructed pipe requirement: 15 diameters upstream; 10 downstream.Flow Repeatability: ± 0.2% of full scaleFlow Response Time: 0.8 seconds (one time constant)Temperature Accuracy: ± 1° F (± 0.6° C)Calibration: Factory Calibration to NIST-traceable standards Zero CAL-CHECK®: In situ, operator-initiated calibration validationTurndown: up to 1000:1 and 100:1 typicalGas Pressure (max): 300 psig (20.7 barg)