Differences between magnetostrictive level gauges and float level gauges

I’m waiting for the answer from the owner, and I’m also torn. Comparison between electric floats and magnetostrictive types.

1. The measurement principles are different: The float level gauge operates on the principle of buoyancy; the float moves as a result of the buoyant force exerted by the medium. This movement is transmitted to the displacement detection element through a torsion tube, and then converted into a standard signal that is sent to the secondary instrument； A magnetostrictive level gauge involves inserting a magnetostrictive tube into the liquid, with a float attached to the tube; the magnet inside the float causes the electromagnetic waves in the magnetostrictive tube to be distorted, generating a return wave. The level is determined by measuring the time it takes for the electromagnetic waves to travel from emission to return. 2. Installation method: Both inner and outer floats are installed on the side walls, while magnetostrictive devices can be installed on the top of the tank or on the side (along with a dissolving tank). 3. The magnetostrictive range is relatively large; float tanks that are over 4 meters in length are generally quite expensive. 4. The magnetostrictive precision is higher than that of floats; it is 0.05 for rigid rods, while floats generally require a precision of 0.5. 5. Regarding the choice of rod, rigid rods can be used over distances of up to 7M, while soft rods are said to be capable of covering distances of 20M (I haven’t seen this in practice). 6. It should work well when used in phosphoric acid, but I’m not familiar with your manufacturing processes, so I can’t be sure. 7. It seems that design institutes in the south prefer to use floaters, while those in the north prefer magnetostrictive multi-point systems. It might be related to the manufacturers and distributors; magnetostrictive types are more expensive than float types.

To correct what was said above: regarding the installation method, the float can also be installed at the top of the tank. What you call an external float is nothing more than a balancing tank designed to eliminate disturbances inside the reactor.

Furthermore, floaters are generally more expensive than magnetostrictive devices. The manufacturing process for torsion bars is largely in the hands of a few manufacturers such as Fisher; almost all torsion bars for electric floaters are supplied by FISHER, with very few being produced by other companies.

I’ve learned from it. Thank you all for your answers; I feel like I understand much better now. I hope everyone will keep discussing this.

:Lol hahahahahaha ahaha, I finally understand what a magnetostrictive level gauge is now. Hahahahahaha ahaha

Torsion tubes can now be manufactured in China as well; what is imported are usually only the final transduction units. Personally, I think Foxboro’s torsion tubes are the best.

This post was last edited by Changfeng Jiwanli on 2012-5-14 22:00. Yes, usually only the Fisher header is specified. If no specific import torsion tube is specified, the manufacturer will generally supply a domestic one, which is still suitable for most applications.

The measured length can reach around 6M for rigid rods, and 18M for flexible cables.

I’ve learned something new; I used to think there wasn’t much difference.