Petroleum Tank Monitoring
An electronic sensor box records the levels of Petroleum based fluids in large tanks scattered throughout a refinery and storage compound. The cost of running twisted pair wire to all the tanks is prohibitive due to installation & maintenance costs and the fact that it is common for tank to be located across asphalt or concrete driveways. To overcome the issues associated with running twisted pair the Digi OEM module was incorporated into the sensor box to provide a wireless means to transport the fluid level data. Multiple tanks can be monitored and the levels reported and recorded back at a single PC located in the office.
Because the sensor box was located in the tank along with the flammable gases and liquids, all the electronics had to meet the standards for intrinsic safety. The customer was trying to get Class 1 Div 1 group D approval for the entire product. During the design cycle, Digi engineers helped out with design reviews and trouble shooting of the interface to the radio to enable the fastest time to market. Also, the design required capacitors for intrinsic safety on the RF output. The recommended capacitors were tested on a network analyzer at Digi to ensure that they would not significantly reduce the transmit power and receive sensitivity of the radios. The product met approvals and has been installed at multiple facilities.