IASP: Powerful Weighing Technology for Greener Energy

"With our BioKat research project, we are investigating how fungal enzyme components in biogas plants can quickly and easily decompose even substances that are difficult to decompose," says Marius Conrady, who is responsible for the research project as a research associate at the IASP (IASP – Institut für Agrar- und Stadtökologische Projekte).

"Residual and waste materials can thus be better utilized in biogas production in the future," adds project manager Dr.-Ing. Patrice Ramm. The series of tests stretching over several months requires highly reliable measurement technology that provides precise data over the entire test period. HBK supports the research team with a comprehensive package of high-quality weighing technology, with the precise PW12C single-point load cell at the heart of it.

Four inconspicuous black cylinders form the core of the BioKat research project. "In our four experimental reactors, we are investigating how different enzyme preparations accelerate the fermentation of our test substrate from whole-crop silage," explains Marius Conrady. "For this purpose, we supply our experimental reactors with 176 grams each of whole-crop silage and water every day after a start-up phase.” An agitator stirs the mass continuously, while a temperature-controlled bath ensures a constant 38 degrees Celsius in the reactors to ensure identical conditions throughout the project duration.

The filling level of the reactors, each with a total capacity of 25 liters, plays a special role in the tests. It has a huge impact on the formation of gas and other important factors such as the torque of the agitators that move the mass in the reactors, as well as the volumetric load. "In previous test series, we could only assess the level via the reactors’ inspection windows," says Marius Conrady. "This was a problem because the mass consisting of whole-crop silage and water is very inhomogeneous and has a high dry matter content. Moreover, foam often forms in the reactor.” For a new series of tests, the scientists are therefore looking for a solution that allows additionally determining the filling level using gravimetric measuring technology. HBK's experts advise the IASP, and together with the scientists they are developing a holistic gravimetric weighing concept ranging from sensor technology to software-based electronic evaluation.

“Our PW12C single-point load cell with a capacity of 50 kilograms is at the heart of the weighing concept for the IASP," says Marcel Richter, Head of Product Management Weighing Technology & OEM Sensors at HBK. "With its integrated off-center load compensation, the load cell is ideal for single-point applications with platform sizes up to 800 mm x 800 mm. In the IASP test setup, a single load cell carries the weight of a complete experimental reactor - offering an overall performance for this design that is unique in the market.” 

The PW12C single-point load cell weighs loads ranging from 50 to 750 kilograms precisely in compliance with the C3 Multi-Range accuracy class. In addition, a cable shield connected to the measuring body provides optimum protection against electromagnetic influences, making it ideal for use in laboratory environments. "Its high rigidity and proven strain-gauge technology from HBK make the PW12C ideal for both static and highly dynamic applications; for example, in checkweighers," says Marcel Richter. "At the same time, the load cell is extremely robust.” 

The PW12C is also suitable for use in harsh industrial environments due to its IP67 degree of protection and individually adjustable overload protection.

"In our BioKat research project, the PAD digital transducer electronics converts the analog signals of the load cell into digital data at a high resolution," says Marius Conrady. "In this way, we can simply record the measurement results for our test setup using a PC, evaluate them and get a quick overview.” With its load cell, electronics, and complete range of accessories, HBK offers scientists at the IASP everything they need from a single source. "We offer a wide range of accessories to build up an ideal measurement chain for our customers," says Marcel Richter. "And our PAD digital transducer electronics provides users with a simple and user-friendly way to digitize analog, strain gauge based load cells or sensors—at extremely high resolution.”

The PAD can be easily connected to load cells by plug and play and is ready for use within minutes. Owing to integrated measurement signal processing with selectable or automatic filters, the transducer electronics guarantees maximum precision, even with the continuous vibration of the experimental reactor’s agitators in the IASP test setup. Its compact, stainless-steel housing and IP68/IP69K degree of protection also make the transducer electronics ideal for the most demanding environmental conditions.

The scientists at the IASP also rely on HBK for software. "We use HBK's PanelX software for calibrating the load cell and for recording, outputting, and visualizing the measured data," emphasizes Marius Conrady. "The intuitive operation of PanelX enabled us to quickly adjust the measurement technology to our test setup and put it into operation. In addition, the software provides us with an easy way to quickly visualize and evaluate our measurement results.”

The PanelX software boasts numerous functions that make HBK measurement technology ideal for a wide range of static and dynamic weighing applications. Users can, for example, rely on extensive software support during the start-up and calibration of weighing technology equipment and benefit from the fast evaluation and visualization of measured data. The integrated frequency analysis is a highlight when evaluating and optimizing complete dynamic applications for instance.

"Due to HBK's precise measurement technology, our current series of experiments allows us to exactly monitor the daily addition of whole-crop silage and water and to compare it with the target quantity," explains Marius Conrady. "This enables us to optimize our processes and, for example, avoid inaccuracies in the daily addition of biomass.”

In addition, scientists can determine the weight loss in the reactors due to the decomposition process more precisely and correlate it with the formation of gas. "In our tests, we measure the formation of gas with a volume flow meter. The weight loss curves and the amount of gas produced correlate very well with each other," says Marius Conrady.