On-line guided wave radar integrity testing

The Verification Reflector function, now available with the Rosemount 5300 Series GWR transmitters, is designed for applications that require periodical transmitter integrity tests to ensure that the level measurement device functions correctly and that overfilling will not occur.

The 5300 with Verification Reflector enables automated transmitter integrity tests without stopping the process or manually raising the product level in the vessel, helping to reduce the risk of accidental spills and enabling either device verification or proof-testing to be completed much faster. There is no need to climb the tank to remove the test measurement device or open the tank to monitor levels. This helps to reduce costs, increase plant uptime and improve staff safety.

In the past, most guided wave radar transmitters required the fluid level in the vessel to be raised to the alarm point. The fluid has to be moved in and out of the tank under test – increasing the risk of spills. The process can take up to half a day to complete. The process needs to be supervised by operators to monitor the tank level –increasing health and safety risks due to the possibility of exposure to the tank contents.

The Verification Reflector function eliminates the need for this procedure by using an adjustable reference reflector fitted to the probe of the guided wave radar. During commissioning, the location and amplitude characteristics of the reflector are stored in the transmitter. When the test procedure is later initiated, the stored reflector data is compared to the current measurement to verify the integrity of the measurement electronics and upper part of the probe.

Compared with traditional diagnostics that only monitor the transmitter electronics, the verification reflector can also be used to diagnose problems with the upper parts of the probe inside the tank – including product build-up, corrosion monitoring and other process related conditions. During the test, the transmitter will output a level corresponding to the reflector position, which can be used to verify the integrity of the transmitter output.