Rotary Point Level Indicators in Silos

Rotary Point Level Indicators Keep You In the Know

Understanding how much dry bulk material is currently inside bins, tanks, and silos is a crucial part of many industrial processes. Too much or too little material within the container can lead to costly disruptions that impact production output. Rotary point level indicators are a tried-and-true tool used for real-time high-, mid- and low-level dry bulk material detection. Wm. Neundorfer & Co. has been helping our customers keep track of the materials inside their containers for over 50 years. In this article, we will break down what rotary point level indicators are, how they keep you informed about what is happening in your containers, and detail three models we recommend for our customers.

What is a Rotary Point Level Indicator?

A rotary point level indicator is a monitoring device that uses a paddle inserted into a container to identify if there is material present at that location within the container. It then alerts the users of this status through different means such as a horn, alarm, or light panel depending on the type of rotary point level indicator and customer’s preference. They are found across a wide range of industries including agriculture, chemical, pharmaceutical, plastics, and many more.

How do they work?

Rotary point level indicators consist of two main sections; a housing unit that is installed on the exterior of the container and a paddle that passes through the container wall into its interior. The housing unit contains all the electronics and terminals to run and power the unit. This includes the motors to run the paddle and the controls.

When the indicator is installed on/in the container, it uses the paddle to determine whether material is present at that location in the container. The indicator is able to tell if material is present by using the current state of the paddle. If the paddle is rotating freely, then the indicators know there is no material present. If the paddle encounters resistance when it tries to rotate, then the indicators know that material is present. Because these indicators are used with a wide range of materials, they can be outfitted with various types of paddles made from various materials. These include standard 3-vane paddles to bayonet paddles and can be made from nylon to stainless steel.

Three Models We Recommend


The BMRX is the most commonly utilized model It provides reliable point level detection and measurement of dry bulk solids in bins, tanks, silos, hoppers, and material conveyors. Mounted on the top or side of a bin, the BMRX alerts operators when bins are full, normally through the use of a horn or light. The BMRX features “de-energized” operation of the motor which shuts the motor down when material is present, saving energy costs and prolonging the motor life. It is CE approved and is appropriate for use in hazardous conditions when explosion-proof protection is needed, featuring Class I, Groups C and D, Class II E, F, and G listings.


The MAXIMA+ is the most advanced of the three models. It features a complete fail-safe system that alerts to the loss of power, failure of the motor, or failure of the electronics, allowing it to be used for process control. Appropriate for a wide variety of bulk solids including powders, pellets, or granular materials, the MAXIMA+ can be wired for either high- or low-level indication depending on the customer’s requirements. It can be mounted on either the side of the bin or at the top of a bin using a shaft extension. To prolong motor life and to optimize energy costs, the motor of the MAXIMA+ will “de-energize” once the shaft stops turning when material comes into contact with the paddle.


The Mini Rotary (MR) is the most compact of the three models. It is ideal for controlling material levels in smaller bins and hoppers where other types of equipment simply will not fit. Its principle of operation is simple: a slow speed motor rotates the paddle when no material is present. When material comes into contact with the paddle, the paddle stops and an alert, such as a light or horn, notifies the operator the bin is full. When the bin is emptied, the paddle begins rotating again. The MR is simple to install on the side or top of a bin and is appropriate for a variety of light to heavy materials. Paddle options are available, making it adjustable for a wide range of material densities.

Rotary point level indicators keep you in the know by providing real-time information on the material levels of your bins, tanks, and silos. They enable you to make informed decisions and help keep your production process working efficiently.  If you think a Rotary point level indicator could be a solution for your application, contact Wm. Neundorfer & Co. today. We have the expertise and experience to ensure you get the correct product for your specific application.

For more information or details on how we can help you select the right equipment for your application, contact Wm Neundorfer & Co today.

We have the expertise and experience to ensure you get the advice and recommendations you require for your specific application.

Wm. Neundorfer & Co. proudly serves Ohio, West Virginia, Western Pennsylvania and Western New York.

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