The Micro-Cal Model 869 is designed for air handling processes in critical environments that require portable, high accuracy and low-pressure documenting calibration to certify pressure needs. It easily provides this capability by performing calibration checks on sensors with accuracies as high as .00025 in. W.C. This battery-powered unit provides a minimum of eight hours of operation, while giving a pressure reading accuracy close to .0001 in. W.C., with fast, stable and repeatable pressure generation better than .0003 in. W.C. With recorded calibration times as fast as five minutes per unit, users will enjoy time-saving benefits, as well as cost savings for service/installation time.