WHOA WHOA WHOA...tap the brakes there. Under NO circumstances may you use another group's data, regardless of whether you cite it or not, unless you have my EXPLICIT permission (and in this instance, you do not). This forum is absolutely NOT a place to be sharing data between groups, and if I catch it happening there are going to be severe consequences. If for some reason there is a need for some data to be shared or distributed, leave it to me to take the reins in spearheading that effort.
Sorry to be a buzz-kill here everyone, but we all have to tread very carefully when it comes to the Engineering Honor Code.
Now for the part where I don't have to sound like a jerk...this post actually brings up an important point...do you actually need the weight of the loading platter? Your 'unloaded' or '0 lb' point on the calibration curve is with the loading platter exerting some non-zero force on the measurement device (giving you a pressure greater than zero)...what meaning would a pressure measurement be with the loading platter not on there? What would be the weight? If you can start thinking about these questions, you'll see that you may not need the quantity you were asking about.