Flow regulation in fertilizer spreaders

Ranaverken is a manufacturer of trailer fertilizer spreaders for agriculture, these trailers are equipped with flow measurement that measure and present the flow of liquid in real time. This gives the tractor driver valuable insights how much fertilizer is spread at the moment. An app gives the driver indicators if the flow must increase or decrease for the right amount of fertilizer.

Now Ranaverken has a new smarter flow regulation that uses the same app, but with extended functionality. The smart flow regulator has automatic calibration, calibration was earlier a complicated and extensive process, now it’s done with a simple push of a button. The flow regulator also incorporates a history function and the possibility to export data for example invoicing, statistics and control. A smart map gives a clear overview where and how the fertilizer has been spread on the field.

The control unit is specifically designed for Ranaverken in everything from hardware to Software with WIFI and CAN-bus communication. The complete development and manufacturing took place in-house from control unit with cables, IOS application to the flow regulator.

A robust design with a clear and simple user interface is important, and both hardware and software are designed and tested to ensure reliability during the entire lifetime.

Regal Components supplies the pressure transmitters used in the system. The pressure transmitter measures in direct contact with the liquid fertilizer. This requires high levels of robustness and long-term stability as the liquid fertilizer often is contaminated with solid debris that can damage the sensor. Due to the contamination and the high viscosity of the fertilizer is it not possible to use a pressure transmitter with a traditional pressure connection as it would clog up which affects the accuracy or in worst case cause malfunction. Instead, a pressure transmitter with a flush membrane pressure connection is used, it makes a flat process connection designed to prevent media to clog the connection.

CFD Simulations (Computational fluid dynamipressure transmitters from different suppliers to ensure that the high requirements were fulfilled. The pressure transmitters were examined after the extensive field tests to evaluate damage and changes in measurement accuracy. After the examination the final choice was a flush membrane pressure transmitter model FPT from Regal Components.

FPT is a very robust front membrane pressure transmitter with a thin-film-on-steel sensor and duplex stainless steel 1.4462 front membrane. Many other front membrane pressure transmitters have piezoresistive sensors, these pressure transmitters have a liquid ex. Silicon oil in between the front membrane and the sensor acting as a transmission media. This makes them sensitive to blows on the front membrane. FPT with it’s thin-film-on-steel sensor is directly connected to the frontal membrane without transmission media, hence it has solid material behind the membrane. This design also allows a thicker frontal membrane which makes FPT a very robust pressure transmitter well suited for this application with contaminated fertilizer and corrosive and chemical environments.

You can find out more about Ranaverken and Insight Engineering on their websites:


Regal Components