Burr size measurement

Box-Behnken design (BBD) matrix and measured vaiues of burr size... 

In order to validate the developed burr size models, five sets of random experiments were performed within the ranges of the process parameters selected and the burr height and burr thickness values were measured. The experimental values were then compared with the predicted values of RSM-based models and it was found that these values were close to each other, as illustrated in Table 7.5. The maximum prediction... 

It is essential to ensure that the following criteria are met otherwise errors will result. First, the mouth of the hole inside the duct must be smooth and flush with the duct inner surface. No burrs or other irregularities must be on the surface in the vicinity of the hole. Second, the hole must be perpendicular to the tube axis. The size of the hole has an effect on the measured pressure as well. A general rule is, the smaller the hole the better. Very small holes do, however, slow down the response of the instrument. Usually the hole diameter is a few millimeters. Note also that the smaller the hole, the greater the risk of blockage. Further information on the effect of the hole size can be found, e.g., in Ower and Pankhurst. 

---