Never zero your probe again
Offset errors in typical Hall probes occur for several reasons:
- Thermoelectric effects, which cause the offset to change with temperature.
- Imperfect contact placement geometry on the sensor, which creates so-called “misalignment voltage” errors that are harder to correct for.
These errors result in probe “drift,” impacting measurement repeatability.
Typical Hall probes must be regularly placed in a zero-gauss chamber to zero out offsets that develop over time.
Lake Shore’s TruZero™ technology eliminates the need to perform these frequent zeroing operations, saving time and ensuring that measurements are always accurate.
This multi-part technology is accomplished through multiple mechanisms:
2Dex™ Hall effect sensors used in FP Series probes are highly symmetrical and uniform, resulting in inherently low zero-field offset voltages
Special insulation used in the cable for optimum dielectric performance.
An advanced sensor excitation “spinning” technique progressively switches between different measurement configurations.
An onboard algorithm combines the sequential Hall voltage readings in a way that eliminates any offsets due to misalignment and thermoelectric effects. This method also reduces flicker noise, meaning that readings are both more accurate and more precise.
This means there is never a need to “zero” the probe before making a measurement. TruZero™ technology allows fast, worry-free, and always accurate measurements.
An experiment was conducted to observe the qualitative benefit delivered by TruZero technology.
- Model 475 and F71 placed in a temperature controlled room.
- Probes placed in zero gauss chambers where magnetic field is practically zero.
- 475 zeroed at the beginning of the experiment.
- Temperature cycled over multiple hours.
- Very slight zero-offset drift with temperature
- No apparent drift with time
- Measurement resolution measured in nT
- More significant zero-offset drift with temperature
- Noticeable drift over several hours
- Measurement resolution measured in µT