How does a magnetostrictive level gauge measure liquid levels in corrosive environments?
1 Answer
Magnetostrictive level gauges are commonly used to measure liquid levels in various industrial applications, including corrosive environments. These gauges work based on the principle of magnetostriction, where a sensing wire is embedded in a tube or a rod made of magnetostrictive material.
Here's how a magnetostrictive level gauge operates in corrosive environments:
Construction: The gauge consists of a rigid and chemically resistant tube or rod made of materials such as stainless steel or other corrosion-resistant alloys. The sensing wire is typically made of a magnetostrictive material like Terfenol-D, an alloy of terbium, iron, and dysprosium.
Installation: The gauge is installed vertically in the vessel or tank where you want to measure the liquid level. It can be mounted at the top of the tank, and its length should correspond to the maximum liquid level you want to measure.
Magnetostriction principle: Magnetostriction is a property of certain materials that causes them to change their shape in response to an applied magnetic field. In the case of a magnetostrictive level gauge, an electrical pulse is sent through the sensing wire, generating a magnetic field around the wire.
Position measurement: The gauge consists of a float that moves up and down with the liquid level. The float is equipped with a magnetic assembly, typically containing a permanent magnet. As the liquid level changes, the float moves along the gauge's length.
Interaction with magnetic field: When the magnetic field generated by the sensing wire interacts with the magnetic assembly on the float, a torsional stress is induced in the wire. This stress causes the wire to undergo a slight deformation, known as magnetostrictive effect or magnetostrictive displacement.
Time of Flight (TOF) measurement: The magnetostrictive level gauge measures the time taken for the electrical pulse to travel along the sensing wire and return to the point of origin. Since the speed of the electrical pulse is constant, the time taken is directly proportional to the distance from the top of the gauge to the liquid level.
Level calculation: The electronic components of the level gauge measure the time of flight and calculate the liquid level based on the known length of the gauge. This information is then displayed on a local indicator or transmitted to a control system for monitoring and control purposes.
The key advantage of using magnetostrictive level gauges in corrosive environments is their ability to withstand harsh conditions due to the use of chemically resistant materials. They offer accurate and reliable level measurements, making them suitable for various industrial applications, including those involving corrosive liquids.
Here's how a magnetostrictive level gauge operates in corrosive environments:
Construction: The gauge consists of a rigid and chemically resistant tube or rod made of materials such as stainless steel or other corrosion-resistant alloys. The sensing wire is typically made of a magnetostrictive material like Terfenol-D, an alloy of terbium, iron, and dysprosium.
Installation: The gauge is installed vertically in the vessel or tank where you want to measure the liquid level. It can be mounted at the top of the tank, and its length should correspond to the maximum liquid level you want to measure.
Magnetostriction principle: Magnetostriction is a property of certain materials that causes them to change their shape in response to an applied magnetic field. In the case of a magnetostrictive level gauge, an electrical pulse is sent through the sensing wire, generating a magnetic field around the wire.
Position measurement: The gauge consists of a float that moves up and down with the liquid level. The float is equipped with a magnetic assembly, typically containing a permanent magnet. As the liquid level changes, the float moves along the gauge's length.
Interaction with magnetic field: When the magnetic field generated by the sensing wire interacts with the magnetic assembly on the float, a torsional stress is induced in the wire. This stress causes the wire to undergo a slight deformation, known as magnetostrictive effect or magnetostrictive displacement.
Time of Flight (TOF) measurement: The magnetostrictive level gauge measures the time taken for the electrical pulse to travel along the sensing wire and return to the point of origin. Since the speed of the electrical pulse is constant, the time taken is directly proportional to the distance from the top of the gauge to the liquid level.
Level calculation: The electronic components of the level gauge measure the time of flight and calculate the liquid level based on the known length of the gauge. This information is then displayed on a local indicator or transmitted to a control system for monitoring and control purposes.
The key advantage of using magnetostrictive level gauges in corrosive environments is their ability to withstand harsh conditions due to the use of chemically resistant materials. They offer accurate and reliable level measurements, making them suitable for various industrial applications, including those involving corrosive liquids.