A licensed public weighmaster shall not enter on a weighmaster's certificate issued by the weighmaster any weight values which the weighmaster has not personally determined, and the weighmaster shall make no entries on a weighmaster's certificate issued by another person. A weighmaster's certificate shall be so prepared as to show clearly what weight or weights were actually determined. If the certificate form provides for the entry of gross, tare and net weights in any case in which only the gross, the tare or the net weight is determined by the weighmaster, he shall strike through or otherwise cancel the printed entries for the weights not determined or computed. If gross and tare weights are shown on a weighmaster's certificate and both of these were not determined on the same scale and on the day for which the certificate is dated, the weighmaster shall identify on the certificate the scale used for determining each weight and the date of each determination.