Comparison of two vacuum recording methods in a quarter individual milking system

The purpose of this study is to develop an approach for introducing a pressure sensor into the milk-tube of a milking system. The purpose for installing a permanent sensor (Test series A) was to measure the vacuum in the milk-tube as precise as it is possible in a certified external vacuum measuring system (Test series B). After calculation of the vacuum deviation at each simultaneously measured data pair, an evaluation was possible. Thus, the most important result of this study was the significant difference in the measuring deviation between test series A and B. At a flow rate of 0.8 l/min and at a distance of 100 mm between teat end and measuring point the deviation for test series A was 0.74 kPa and for test series B was 0.42 kPa. However, the measuring deviation is higher and consequently the quality of measuring is slightly lower in test series A. For this reason, the construction work for developing a vacuum control system with permanently installed pressure sensors and online measurements of vacuum was carried out. But the constructed casing should be improved to reach a lower measuring deviation. Whether this system is applicable for vacuum controlling after an improvement step or not, depends on the measuring deviation estimated by comparing vacuum at the teat end and under the teat cup. First results show a mean measuring deviation between both measuring points of about 1.0 kPa. Online vacuum controlling at the teat end can improve udder health and milk quality.