{"content":[{"text":"DATA COLLECTION and \n EVALUATION \n By Jim McConchie \n In order to monitor production using Statistical Process Control techniques \n (SPC), a multitude of data is needed to ensure that the information is a true \n representation of the process.","bbox":{"left":0.151205,"top":0.081662,"width":0.6700419999999999,"height":0.166589}},{"text":"Before the advent of computers this data was laboriously recorded, the \n averages and necessary statistical information calculated and the results \n plotted. It was then up to the inspector to check for trends or outliers. \n Problems were not obvious until the results had been plotted and there was a \n large time delay.","bbox":{"left":0.151205,"top":0.261662,"width":0.689175,"height":0.08514099999999997}},{"text":"Now with computerisation the data can be collected REAL-TIME and the \n statistics calculated immediately. Trends are checked for and the average of \n the sample is compared to the specifications and control limits which have \n been preset. If the process is out of specification an alarm sounds and a \n message can be flashed onto the monitor stating the discrepancy.","bbox":{"left":0.151205,"top":0.360213,"width":0.6792130000000001,"height":0.08521200000000001}},{"text":"Because the data is analysed REAL-TIME the scrap produced is kept to a \n minimum and can be isolated.","bbox":{"left":0.151205,"top":0.458764,"width":0.657828,"height":0.03604299999999999}},{"text":"EQUIPMENT :","bbox":{"left":0.151205,"top":0.508218,"width":0.13100400000000004,"height":0.019696000000000047}},{"text":"The first essential is a data collection device; these can be","bbox":{"left":0.151205,"top":0.541282,"width":0.5199539999999999,"height":0.01958199999999999}},{"text":"(a) Handheld -","bbox":{"left":0.151205,"top":0.580475,"width":0.129001,"height":0.01958199999999999}},{"text":"Dataputers \n DataMytes \n These data collectors are robust and can be carried to the \n workplace and up to three instruments can be directly connected \n Mitutoyo \n TESA \n Notebook Computers \n These data collectors are not as robust as the hand helds and \n need to be placed on a secure mounting during use. \n Personal Computers","bbox":{"left":0.360169,"top":0.580475,"width":0.5759000000000001,"height":0.25438000000000005}},{"text":"(b) Portable -","bbox":{"left":0.151205,"top":0.683444,"width":0.11776900000000004,"height":0.01958199999999999}},{"text":"(c) Fixed -","bbox":{"left":0.151204,"top":0.815273,"width":0.090753,"height":0.01958199999999999}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}