arrow_back_ios

Main Menu

See All Acoustic End-of-Line Test Systems See All DAQ and instruments See All Electroacoustics See All Software See All Transducers See All Vibration Testing Equipment See All Academy See All Resource Center See All Applications See All Industries See All Insights See All Services See All Support See All Our Business See All Our History See All Our Sustainability Commitment See All Global Presence
arrow_back_ios

Main Menu

See All Actuators See All Combustion Engines See All Durability See All eDrive See All Production Testing Sensors See All Transmission & Gearboxes See All Turbo Charger See All DAQ Systems See All High Precision and Calibration Systems See All Industrial electronics See All Power Analyser See All S&V Hand-held devices See All S&V Signal conditioner See All Test Solutions See All DAQ Software See All Drivers & API See All nCode - Durability and Fatigue Analysis See All ReliaSoft - Reliability Analysis and Management See All Test Data Management See All Utility See All Vibration Control See All Acoustic See All Current / voltage See All Displacement See All Load Cells See All Pressure See All Strain Gauges See All Torque See All Vibration See All LDS Shaker Systems See All Power Amplifiers See All Vibration Controllers See All Accessories for Vibration Testing Equipment See All Training Courses See All Whitepapers See All Acoustics See All Asset & Process Monitoring See All Custom Sensors See All Data Acquisition & Analysis See All Durability & Fatigue See All Electric Power Testing See All NVH See All Reliability See All Smart Sensors See All Vibration See All Weighing See All Automotive & Ground Transportation See All Calibration See All Installation, Maintenance & Repair See All Support Brüel & Kjær See All Release Notes See All Compliance See All Our People
arrow_back_ios

Main Menu

See All CANHEAD See All GenHS See All LAN-XI See All MGCplus See All Optical Interrogators See All QuantumX See All SomatXR See All Accessories See All Accessories See All BK Connect / Pulse See All API See All Microphone Sets See All Microphone Cartridges See All Acoustic Calibrators See All Special Microphones See All Microphone Pre-amplifiers See All Sound Sources See All Accessories for acoustic transducers See All Experimental testing See All Transducer Manufacturing (OEM) See All Accessories See All Non-rotating (calibration) See All Rotating See All CCLD (IEPE) accelerometers See All Charge Accelerometers See All Impulse hammers / impedance heads See All Cables See All Accessories See All Electroacoustics See All Noise Source Identification See All Environmental Noise See All Sound Power and Sound Pressure See All Noise Certification See All Industrial Process Control See All Structural Health Monitoring See All Electrical Devices Testing See All Electrical Systems Testing See All Grid Testing See All High-Voltage Testing See All Vibration Testing with Electrodynamic Shakers See All Structural Dynamics See All Machine Analysis and Diagnostics See All Calibration Services for Transducers See All Calibration Services for Handheld Instruments See All Calibration Services for Instruments & DAQ See All On-Site Calibration See All Resources See All Software License Management

Mini Temperature Sensor Enables Energy-Saving Coffee Production

PTB, Germany

Cooperation as the Basis for Innovation

PTB makes its technology available through licenses. HBK, in turn, cooperates with the PTB license holders. The close collaboration among PTB, license holders and HBK forms anideal basis for innovative development. Dr. Hammerschmidt expressed his approval: "We like working together with HBK. With them, we find the technical competence and reliable, high-quality products we need for trend-setting methods."

chevron_left
chevron_right

Energy-Saving Coffee Production

Nearly a billion kilowatt hours of energy are expended annually by the food industry in Germany for drying and roasting coffee beans, nuts, and fruits. Finding the optimum temperature and process time is the key to major potential energy savings. Now, the German National Metrology Institute (PTB), using a compact temperature sensor from HBK, has developed a new process for measuringthe thermal conductivity and thermal diffusivity of small objects such as coffee beans. Until now, the thermal capacity of coffee beanscould only be determined using pressed ground coffee. The structure of the material plays no role for this material constant. Thermal transport properties, on the other hand, are structure-dependent. Therefore, they can only be measured with sufficient accuracy using whole coffee beans. Since coffee beans are too small for previous measurement technology, thermal conductivity and thermal diffusivity could only be roughly estimated.

Extremely Small and Powerful

The TT-3/100 temperature sensor from HBK is only 50 μm thick, with a measuring surface of 3.1 mm x 3.0 mm. With these dimensions, it comes very close to being a "punctiform" sensor, which is how it was represented in the mathematical modeling for this new method. A wide application temperature range from -50°C to +180°C makes it possible to use the sensor for both freeze-drying and roasting coffee beans

 

Innovative Measurement Method

Thanks to the miniature dimensions of the TT-3/100, the PTB was able to develop an innovative measurement method for determining the thermal properties of coffee beans. The method consists of several steps. The coffee bean is divided in half with the sensor placed in between. The contact surfaces need to be smooth to ensure good thermal contact. The sensor is not glued in place; rather, it is clamped, and acts as both temperature sensor and defined source of heat at the same time. 

With a power supply of 8 to 10 mA, the TT-3/100 heats up during measurement. The more the bean conducts inside heat to the outside, the faster and more intensely the temperature and electrical resistance of the sensor rise. 

The measurement results for thermal diffusivity and thermal conductivity are ready in just a few minutes. It is also possible to calculate the specific thermal capacity of the bean if its density is known. That material property can simply be determined according to Archimedes' principle. Instead of thermal conductivity, the humidity of a bean can also be determined.

Accurate and Reliable Results

The reliability of the method has been demonstrated, starting with reference specimens with precisely known thermal transport properties. The measured values for specific heat of a bean can be compared with those of ground coffee. They match very closely.

 

Efficient Measurement for Various Applications

Dr. Ulf Hammerschmidt of the PTB is confident that the new method will open up newapplications in diverse industries. The importance of thermal conductivity and thermal diffusivity as material parameters extends well beyond the food industry. The method can also speed uptesting, monitoring, and approval of new insulation materials in the building industry, providing reliable results within minutes, compared to a few days. Assessments of existing building materials could be supported by simple field measurements.

PTB - German National Metrology Institute

PTB is the National Metrology Institute of Germany with scientific and technical service tasks. PTB measures with the highest accuracy and reliability – metrology as the core competence. PTB stands for progress and reliability in metrology for the benefit of society, trade and industry, and science.

Learn more about PTB

Technology Used

No more result to load