The packaged system as successfully developed in adaptation of data logging techniques to measure the pressure and temperature changes automatically. It also incorporates a safety laboratory test procedure regardless of the operators experience and knowledge of the physical characteristics of the liquidpetroleum gases. Thus allowing inexperienced operators to use the system safety and effectively. The test system comprising of the modified test apparatus, data logging equipments and the microcomputer hardware and software system, foams a complete compatible package which can determine the gauge vapour pressure-temperature relationship automatically. Commercial butane as used as the test sample. The pressure readings were verified against those in a literature source. The pressure transducer and thermocouple were calibrated periodically, therefore the calibration package was developed and incorporated in the software system. The signal from the sample tests are automatically calibrated and the actual output readings are then shown on the screen. Recommendations were given to enable the system to be further developed in automating the procedures, especially for L.P.G with very low boiling point.