Wednesday, March 9, 2016

Innovative Non-contact Tote Level Monitoring Application

One of the most attractive features of non-contact microwave level measurement is its ability of the radar waves to penetrate through plastic walls. Because of their low dielectric constant, plastic allows measurement without losing the impulse strength of the emitted signals and the detection of the reflected microwave impulses. 

This comes in very handy when measuring level of chemically aggressive fumes and vapors. One approach is to protect the stainless steel horn antenna with a plastic enclosure. Another approach is to measure the stored chemicals from a distance through the wall of the plastic tank or container. 

Recently, a Nivelco non-contact microwave level transmitter was specified for corrosive chemical storage tanks in a local plant. The handling and dispensing of the corrosive chemicals is very challenging, particularly for the instrumentation manufacturers.  In this application, the chemicals were stored in two closed plastic totes.  It was very important to continuously monitor the level of these totes in real time. The local sales engineer recommended using non-contact radar measurement and specified a Nivelco PiloTREK because of its high accuracy and highly reliable level measurement through a plastic tank wall. 

Upon installation a problem developed. The metal cage holding and supporting the tote introduced false signals. Again, the local sales engineer came up with a solution. A Nivelco PiloTREK WEM-150-4 with DN 50 stainless steel horn antenna was specified and careful attention was paid the the placement of the horn antenna. After some trial and error, the horn was placed about 3 feet above the tote, and focussed on an area between metallic bars.

Along with the Eview2 configuration software, setup was quick and easy. During the tests the Nivelco microwave transmitter did extraordinarily well, reaching accuracies of 0.12 inch. Additionally, a mock test simulating a rapid decrease in level was run, and the transmitter managed the situation perfectly. 

In the end the customer was very satisfied with the test results and the use of the Nivelco’s device and greatly appreciated having the experience and knowledge of his local technical sales representative.