Plate count weight distribution

Figure 6 shows calibration curves for three other two column combinations, each representing 30,000 to 40,000 plates per set. The 10 A° plus 10 A° curve can be interpreted to show a deficiency in relative pore population in the range equivalent to about 50,000 to 600,000 molecular weight. The other two, properly calibrated, can conceivably be used for determination of molecular weight distributions. However, utility for resolution of specific polymodal mixtures is too difficult to assess from calibration curve alone. How much curvature of a calibration curve translates into utility or non-utility Calibration curves indicating pore size populations all have the same shape for given column combinations whether the plate count level is 5000 plates or 20,000 plates or 80,000 plates. 

Because of the heavy weight of lead shields and steel stands, the counting room should always be on the ground floor. Even with this stipulation, the floor should be built of high density concrete with imbedded I-beams for increased support. Some laboratories use a thick steel plate under the equipment footprint to distribute the weight over a larger area. 

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