A Strain gauge amplifier is a specialized measurement amplifier system designed to acquire and process the very small electrical signals from strain gauges (SG). Since the changes in resistance of a strain gauge caused by mechanical loads are extremely small, the resulting measurement signals cannot be processed directly with sufficient accuracy. Only by using a suitable amplifier can these signals be made usable for further measurement processing.
In addition to signal amplification, modern strain gauge amplifiers often perform other tasks such as providing power to the sensor, supplying the bridge, filtering signals, and compensating for interference. This enables highly precise measurement of strains, forces, moments, or weights.
Depending on the measurement task and the requirements for accuracy, immunity to interference, and measurement dynamics, different amplification methods are used:
Carrier Frequency Differential Amplifier (CFD Amplifier)
In this process, the measuring bridge is powered by a high-frequency AC voltage. Carrier-frequency amplifiers are characterized by high long-term stability and excellent suppression of interference signals and thermal effects. They are frequently used in demanding industrial and testing applications.
DC Differential Amplifier (DC Amplifier)
Here, the measuring bridge is powered by a DC voltage. DC amplifiers enable high measurement speeds and are particularly well-suited for dynamic measurement tasks. They are frequently used in test benches, experimental setups, and laboratory applications.
TDC (Time-to-Digital Conversion) Method
In this modern measurement method, changes in the sensor signal are digitally evaluated directly through time measurements. This allows for very high resolutions and measurement accuracies. The method is increasingly being used in modern measurement systems, particularly when high precision and digital signal processing are required.
Typical applications for DMS amplifiers:
- Force Measurements
- Torque Measurements
- Weighing and Dosing Systems
- Material and Component Testing
- Structural and Load Analyses
- Test Bench and Testing Technology
- Machine and Equipment Monitoring
Advantages of modern DMS amplifiers:
- Precise detection of even the slightest signal changes
- High measurement accuracy and resolution
- Integrated sensor power supply and bridge power supply
- Good immunity to interference, even in industrial environments
- Suitable for static and dynamic measurements
- Direct integration with modern data collection systems
DMS amplifiers are an essential component for the reliable measurement of strain and the parameters derived from it. They are used wherever even the smallest mechanical changes must be measured and evaluated with high accuracy.