What is Zero-g Offset Variation from RT over Temp.?
Zero-g offset variation from RT over Temp. is the change in the zero-g offset from the room temperature zero-g offset as the temperature changes. The variation is measured at Kionix by placing the accelerometer in a thermal chamber. First, the zero-g offset voltage is measured at 25C. Then the chamber is heated to a high temperature (usually 85C), and the zero-g offset voltage is measured a second time. Finally, the chamber is cooled to a low temperature (usually -40C), and the zero-g offset voltage is measured a third time. After the testing is complete, the data is analyzed. The zero-g offset voltage at 25C is subtracted from each of the measurements. The resulting change in voltage is divided by the accelerometer’s sensitivity to express the change in output in terms of acceleration (g or mg). The three data points (high temp., 25C, and low temp.) are plotted on a graph, and a least squares linear fit is done. The resulting slope (expressed in mg/C) gives the variation of the zero-g
