When deploying high-precision seismic monitoring systems, ensuring proper scaling between the accelerometer and the data logger is critical. In this technical guide, we explain how to verify the SARA SA10 Force Balance Accelerometer (FBA) when used with the SL06 24-bit Data Logger, including how to calculate the digital transduction factor using a simple field method.
This procedure is commonly performed during installation, commissioning, or periodic system verification.
Overview: SA10 Force Balance Accelerometer (FBA)
The SARA SA10 is a professional-grade force balance accelerometer designed for:
- Seismic monitoring networks
- Structural health monitoring (SHM)
- Earthquake early warning systems
- Industrial vibration measurement
- Research and academic applications
Each SA10 sensor is delivered with an individual factory calibration test report specifying:
- Serial number
- Nominal sensitivity
- Calibration constants
- Functional verification results
Nominal Sensitivity Options
The SA10 is typically supplied in one of two configurations:
- 5 V/g
- 10 V/g
When connected to the SL06 data logger configured with a ±10 V input range (20 Vpp total dynamic range), only two corresponding transduction scaling configurations are possible.
Proper scaling ensures that digital counts recorded by the SL06 accurately represent acceleration in engineering units (g).
Understanding the Transduction Factor
The transduction factor converts raw digital counts into acceleration units (g).
Acceleration Formula
Acceleration (g) = Counts × Transduction Factor
Correct scaling is essential for:
- Accurate waveform analysis
- Peak Ground Acceleration (PGA) calculations
- Structural response studies
- Regulatory reporting
Field Verification Using the Gravity Flip Method
One of the advantages of force balance accelerometers is the ability to perform a simple field verification using gravity as a reference.
Step-by-Step Procedure
- Power on the SL06 logger and confirm recording.
- Verify that the channel input range is set to ±10 V.
- Place the SA10 sensor on a stable, level surface.
- Carefully rotate the sensor so that one sensitive axis aligns with gravity (+1 g).
- Observe the digital counts displayed or recorded.
Example Transduction Factor Calculation
Assume the SL06 records approximately:
4,194,304 counts ≈ 1 g
The transduction factor is calculated as:
Transduction Factor = 1 g / 4,194,304 counts
Transduction Factor = 0.000000238 g/count
This means:
- Each count represents 0.000000238 g
- Scaling can be validated quickly in the field
- System performance can be confirmed without laboratory equipment
What to Look For During Verification
A properly functioning SA10 + SL06 system should show:
- Symmetric +1 g and −1 g values
- Stable readings without excessive noise
- No clipping or saturation
- Consistency with the factory calibration report
If values are inconsistent:
- Verify wiring and grounding
- Confirm input range configuration
- Check sensor orientation
- Review factory calibration documentation
Important Notes
The gravity flip method:
- Is intended for functional field verification
- Does not replace accredited laboratory calibration
- Is not a substitute for traceable recalibration when contractually required
For projects requiring traceable recalibration services, contact QuakeLogic directly.
Why Proper Scaling Matters
Improper transduction configuration can lead to:
- Underreported or exaggerated acceleration values
- Incorrect structural response analysis
- Faulty earthquake early warning thresholds
- Data rejection in research publications
Ensuring proper SA10 scaling with the SL06 logger protects both data integrity and system reliability.
Conclusion
The combination of the SARA SA10 FBA sensor and the SL06 24-bit data logger provides high dynamic range and low-noise seismic recording suitable for professional monitoring applications.
Using the simple gravity flip verification method, field engineers can quickly confirm:
- Sensor polarity
- Scaling accuracy
- Digital transduction factor
- Overall system functionality
For more information about SA10 sensors, SL06 dataloggers, or complete seismic monitoring systems, contact QuakeLogic Inc.