Can one PLC be standardized on calibration benches that use different measurements?
Summary: Watt Technology builds water meter calibration benches; these benches use several different measurement systems to verify and compare the water displacement. Watt wanted to specify a PLC could be installed to control each of the water meter calibration systems they offered. This PLC needed to be flexible enough to adapt to the different requirements of each calibration method, as well as being user-friendly. They selected the Unitronics Vision1210 PLC controller +HMI.
Watt Technology, based in Brazil, is an engineering company offering industrial automation solutions. They design and manufacture a variety of automated systems and automated process devices, dedicated to meeting customer needs with quality, reliability and efficiency. One area they have had particular success in is their line of automated water meter calibration benches.
Water meter calibration systems work by running a set amount of water, confirmed through an independent measurement, through a system with the water meter being tested.
The flow recorded by the water meter is compared to the control measurements to ensure a consistent reader. Watt Technology offers machines that use one of three control measurement systems. The first is volumetric, which measures the volume of displaced water directly using material measurements. The second method is the gravimetric method; the displaced water volume is confirmed by calculating the volume based on weight and density, which in turn is measured using a temperature sensor to calculate the heat resistance. The third method that Watt Technology uses is the master meter method. In this method, the readings of a standard water meter and the electromagnetic meter being tested are compared. This method is more dynamic than the others; the system starts moving the fluid in a laminar fashion at a set flow rate and triggers a stop once it reaches a predetermined volume.
Each water meter calibration bench that Watt Technology manufactures needs a PLC to control and monitor the system, as well as a high-resolution HMI panel for the supervisory settings. Watt was intrigued by the idea of an all-in-one PLC+HMI controller, which would offer a compact, streamlined solution.
They settled on Unitronics, an industry leader in PLC manufacturing, and, since first implementing Unitronics, have used almost all of the Vision series PLC+HMI units on various applications.
Watt Technology had particular success with the Unitronics Vision1210. This high-performance PLC has an integrated 12-inch color-touch HMI and options for both local and remote I/O. The Vision1210 is programmed in a single software environment, enabling quick and easy application development. Ronney Muniz Soares explains “The Watt Technology has been using all Unitronics line due to its practicality on schedule, reducing the physical space in applications and excellent resolution screens specifically in the Vision line. What makes our leaner applications and consequently have contributed to reducing costs in projects.”