The HemoCue® Hb 301 Analyzer features a built-in "self test" which ensures the accuracy of the tests made as well as the results. The system can be verified using liquid controls and is factory calibrated against the ICSH reference method for hemoglobin and needs no further calibration. Using the device, the results can be determined in about 10 seconds under an operating temperature of 10-40 °C (40-104 °F). To continue, the analyzer can be stored at temperature 0-50 °C (32-122 °F) and has a measurement range of 0-25.6 g/dL (0-256 g/L or 0-15.9 mmol/L). It weighs 500 g (1.10 pounds) with batteries installed has a correlation of 0.99 when compared to the reference method (ICSH method).