A signal conditioner/amplifier is a critical component within a load cell system. It receives the low-level millivolt output from a strain gauge-based load cell and performs essential functions including signal amplification, filtering to remove electrical noise, excitation voltage supply to the load cell, and often analog-to-digital conversion. This prepares the signal for accurate interpretation by a display, controller, or data acquisition system.
The device provides a stable excitation voltage (e.g., 5V or 10V DC) to the load cell's Wheatstone bridge. It receives the resulting differential millivolt signal, which is proportional to the applied force. This signal is first filtered to remove high-frequency noise. It is then amplified by a high-gain, low-drift instrumentation amplifier to a standardized output level (e.g., 0-5V, 0-10V, 4-20mA). Some models include analog-to-digital converters for direct digital output.
Typical parameters include input sensitivity of 0.5–3.0 mV/V, excitation voltage of 5–12 V DC, output signal of 0–10 V DC, accuracy class of 0.05–0.1% FS, adjustable bandwidth of 0–1000 Hz, operating temperature of -40 to 85°C, supply voltage of 9–36 V DC, IP rating of IP54–IP65 (per IEC 60529), housing material of aluminum, and weight of 0.3–0.8 kg. These values are reference ranges and must be verified for the specific model and application.
When selecting a signal conditioner/amplifier, consider the load cell's rated output, required output signal type, accuracy needs, environmental conditions, and power supply availability. Verify model-specific specifications and standards with the legal manufacturer or supplier before procurement. The device is typically housed in a metal or plastic enclosure and contains a printed circuit board with integrated circuits and electronic components.
The device supplies a stable excitation voltage (e.g., 5V or 10V DC) to the load cell's Wheatstone bridge. The load cell produces a differential millivolt signal proportional to the applied force. This signal is filtered to remove high-frequency noise, then amplified by a high-gain, low-drift instrumentation amplifier to a standardized output level such as 0-5V, 0-10V, or 4-20mA. Some models include analog-to-digital converters for direct digital output.
