Lake Shore Model 420 Gaussmeter User’s Manual
Operation
3-7
Consider gaussmeter, probe, and
magnet tolerances before making
critical measurements. The
accuracy of the gaussmeter
reading is better than ±0.1% of
reading and ±0.005% of range. An
absolute accuracy reading for
gaussmeters and Hall probes is a
difficult to specify, because
measurement variables are difficult
to reproduce. For example, a 1°
error in alignment to the magnetic
field causes a 0.015% reading
error. The best probes have an
accuracy of ±0.1%. This implies
that the absolute accuracy
measurement of a magnetic field
can be no better than ±0.15%
under the best of circumstances,
and more likely 0.20% to 0.25%.
+B
Deviation from
Perpendicular
(
θ)
θ)
θ)
θ)
Error
0°
0%
5°
10°
15°
20°
30°
45°
0.4%
1.5%
3.4%
6.0%
13.4%
29.3%
Effect of angular variations on
percentage of reading error
where % Error = (1 – cos
θ)
100
Figure 3-5 Effect Of Angle On Measurements
Summary of Contents for 420
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