Pressure Control Design by Fieldbus System for the Pressure Gauge Calibration

This paper presented the pressure control by Fieldbus system for the pressure gauge calibration. The data in control is standard communication. The programs for control system are classified into 2 parts, the one for controlling the external element and the other for creating the graphic display. The result of control can be monitor. The program for control can be create the function to computer and send the result to control external element. The program for creating graphic and monitor the result of control can be setting the method of monitoring and the result of control. We can be control the both of the programs for control the external element and the program for create graphic and monitor the result of the control system. Finally, the pressure gauge calibration using air pressure gauge as an intermediary is presented in this paper. The standard pressure gauge is calibrated in the working standard commonly used in the industry. The calibration method of DAkkS-DKD-R 6-1 standard guide line is deployed, where the error margin in measuring the pressure of the pressure gauge does not exceed the accuracy value to set by the factory manufacturers throughout the measurement range (+/- 0.5% of span). At least seven uncertainties are determined. It is found that the value of expanded uncertainty is significantly affected by some certain variables. The experimental result of the UUC studied in this paper show that the maximum error value of measurement is +0.008 kg/cm(2) at 2.0 kg/cm(2), which is in the range of accuracy value specified by the manufacturer (+/- 0.5% of span = +/- 0.02 kg/cm(2)). Moreover, when combining the maximum error value of the measurement obtained from the experiment with the expanded uncertainty (U-exp) = +/- 4.672 x 10(-3) kg/cm(2), it is also found that the result is still in the accuracy value specified by the manufacturer. Therefore, a calibration certificate of UUC can be issued for UUC utilization.