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T1 Hall Probe System
25 kHz sampling
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0.000
0.002
0.004
100 Hz sampling
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0.00
0.50
1.00
A quantitative to way to look at the effect of the effect of the averaging at different sampling
rates is to look at the standard deviation of repeat readings. For the results in the plots above the
standard deviation goes from 0.012% of the field reading down to 0.0005% (5 ppm) as the
sampling rate is reduced from 25 kHz to 10 Hz.
The excellent precision and stability of the Hall device and the analog circuitry means that the
resolution of the digitization by the T-1 can appear in the results under some measurement
conditions, particularly if the measured field is very stable.
The T-1 analog to digital converter has 16 bit resolution, or 15 bits for each of positive and
negative polarity fields. For the example data below, the range setting for the permanent magnet
measurement was changed from 7 kGauss to 28 kGauss. This means the digitization steps
changed from 0.21 Gauss to 0.85 Gauss, and this is evident in data taken of stable fields at high
T1 User Guide
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0.006
0.008
0.010
0.00
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1.50
2.00
2.50
T1_UG_210314
1 kHz sampling
0.05
0.10
0.15
10 Hz sampling
0
5
10
15
0.20
0.25
20
25
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