Hello Rajeevan. When calibrating your load cell, you need at least two points to successfully calibrate over all ranges. Additionally, if you wish to take measurements around the 10 tonnes mark, I would recommend finding some loads that are around this mark which will lead to more accurate measurements. If your actual load cell isn't specified to have that low of a range, I would recommend also acquiring a load cell that has the range to handle the measurement that you are attempting to measure.
In terms of your continuous acquisition which is populating a text file at a rate of 4 MB per minute, I would recommend decreasing the sample rate if at all possible. If this runs continuously for 2 hours, it will create a text file of approximately 1/2 a gigabyte. LabVIEW can handle this if you populate the text file as fast as you are acquiring samples on the DAQ card. However, it will probably take a few revisions to get this to work perfectly for an extended period of time.
Brian F
Applications Engineering
National Instruments
