These unique components operate by sensing the position of a magnetic buoy in a sample chamber using electrical pulses. The transmitter head converts the torsional stress wave that propagates through a sensor wire into a time of flight measurement, providing float level detection that is accurate to within 0.01% of the full scale.
The extreme sensitivity and accuracy of magnetostrictive level transmitters are enhanced by their modular design and rugged capabilities. This enables reliable float level measurements in demanding areas of application, including liquid gas level and interface measuring.
ABB’s LMT Series magnetostrictive level transmitters are divided into the LMT100 and LMT200 models. In a previous blog post, we explored the applications of LMT200 magnetostrictive level transmitters. Today, we will underline the liquid carbon dioxide gas (CO2) applications of the LMT100 series magnetostrictive level transmitter.
Outlining the LMT100 magnetostrictive level transmitter
The LMT100 is a direct in-tank magnetostrictive level transmitter that directly probes a containment vessel with a stainless steel sensor tube. Alternative probe materials are available for specialized applications including Alloy 20, Hastelloy® C-276, and FEP-TEFLON® jacketed. Each of these materials houses the sensor wire that carries the current pulse and generates the requisite magnetic field. This passes through the dual float compartment where the torsional stress wave originates.
This innovative arrangement has proven successful for level measurements of volatile substances and gases under cryogenic conditions. It has also helped improve essential operating processes to optimize storage and handling procedures.
LMT100 magnetostrictive level transmitter in CO2 measurement
Carbon dioxide (CO2) is an inert gas that is ubiquitous on earth, representing roughly 0.03% of the atmosphere and finding a range of end-use applications in each of its primary forms. At room temperature, CO2 enters a gaseous state that is approximately 1.5 times heavier than air and is broadly used for carbonation of food and beverage products. In its solid state, CO2 is known as dry ice which is used in an array of cooling applications.
Liquid CO2 is only formed when the gas is expanded in lower pressures and, preferably, refrigerated at temperatures below 0°. Storing low-pressure CO2 in a cryogenic storage tank requires careful monitoring of both pressure and temperature, which can complicate ongoing level measurements.
ABB’s LMT100 magnetostrictive level transmitters enable ongoing level measurement of liquid CO2 in low pressure, cryogenic containers owing to their sensor well compatibility. The rigid sensor tube can be removed from the storage vessel without affecting the ambient temperature or pressure within the container. This arrangement was successfully used in the cryogenic pressure vessels of a Virginia CO2 processing plant, where containers were maintained at ambient temperatures of between -26 and -40°C. The robust sensor tube is inherently resistant to sub-zero temperatures and is subsequently able to withstand freezing during processing when temperatures are sustained at -40°C.
Two LMT100 magnetostrictive level transmitters were used to monitor the levels of liquid CO2 in interconnecting tanks, providing constant monitoring with no impact on process temperature or pressure.
Magnetostrictive level transmitters from ABB
ABB is one of the world’s leading suppliers of process monitoring equipment for industrial applications. Our magnetostrictive level transmitters have demonstrated the unique potential for safe and reliable measurement of process containers in demanding areas of application, including CO2 and propane gas monitoring.
If you would like any more information about our magnetostrictive level transmitters, simply find your local contact using the form below.