Pur•Chek ™ ProInstruction 2100-9001 94.2 Turning On the UnitConnect the included AC power supply to the 12VDC power input jack on the back of the unit. Plug in the ACpower supply to a 110-220 VAC outlet.NOTE: If the optional battery module is installed and charged, the AC power supply is notrequired.Press the left, soft key, power button and the splash screen shown in Figure 1 will appear for approximatelythree seconds, followed by the warm up screen for three minutes (Figure 2). After the warm up, the calibrationscreen shown in Figure 3 will appear.SOFTWARE VERSIONXXX XX.XXXWARMING UPPLEASE WAITREADY TO AIR CAL1. DISCONNECTHOSE FROMTANK2. PRESS CAL TOSTARTOFF HELP CALFigure 1. Figure 2. Figure 3.4.3 CalibrationEach time the Pur•Chek™ Pro begins a new test cycle it must first self-calibrate. The calibration takes 95seconds (Figure 4) and brings fresh air into the unit via an internal pump. This fresh air purges any excessrefrigerant from the unit and ensures accurate test results. Calibration requires that the hose be disconnectedfrom the refrigerant cylinder or air conditioning system. The calibration of the unit will expire after approximatelyfive minutes of inactivity. If this occurs, the screen shown in Figure 5 will be displayed requiring the calibrationto be initiated again.CALIBRATINGTHIS WILL ONLYTAKE 95 SECONDSCALIBRATION TIMEHAS EXPIREDDISCONNECT HOSEFROM TANK ANDPRESS CAL TORECALIBRATECALFigure 4. Figure 5.After calibrating, the unit will display the screen shown in Figure 6. Connect the hose to the tank and press test.The Pur•Chek™ Pro will display the screen shown in Figure 7. If you wish to change any of the factory defaultsettings, refer to Section 5.READY TESTINGPLEASE WAITANALYZING THEREFRIGERANT1. CONNECT HOSE2. OPEN VALVE3. PRESS TESTHELP CALFigure 6. Figure 7.