Dayu Electronics: External-Mount Level Switches Cannot Measure Containers with 60mm Wall Thickness

A customer asked us: 'Can an external-mount level switch be used to measure liquid in a container with a wall thickness of 60mm?'

The answer is no; external-mount switches can only measure containers with a wall thickness of up to 4mm.

The working principle of an external-mount level switch is that the transducer is attached to the outer wall of the container, emits ultrasonic waves that penetrate the tank wall and come into contact with the liquid, and the signal change is used to determine the liquid level. Sound waves attenuate as they propagate through the metal wall—the thicker the wall, the more severe the attenuation. Within a wall thickness of 4mm, the signal can still penetrate effectively; beyond this thickness, the sound wave penetration rate drops significantly, and the transducer either cannot receive an echo or the signal is too weak for reliable judgment, making the measurement unreliable.

So what about containers with a 60mm wall thickness? There is a solution—just switch to a different sensor. In this case, we recommend a customized insertion-type level sensor. The transducer extends directly into the container and contacts the liquid, so the signal path is short and energy loss is minimal, making thick walls a non-issue.

The insertion type requires drilling a hole in the tank wall for installation, which is different from the 'no hot work' feature of external-mount types, but it is the most direct and effective way to measure liquid level in thick-walled tanks.

So if you are dealing with a thick-walled container, there is no need to dwell on external-mount types; directly considering an insertion-type solution is more reliable.

If your container material, wall thickness, and measurement requirements are somewhat special and you are unsure about the right choice, feel free to contact Dayu Electronics' technical staff directly. Tell us your operating conditions, and we will provide specific recommendations.