Boltek EFM-100 - Interpreting the Data Display; Figure 24: Approaching Thundercloud; Figure 25: Increasing Field Due to Approaching Thundercloud

C H A P T E R 4 - O P E R A T I O N
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Interpreting the Data Display
Often the first indication of an approaching thundercloud is a positive field reading followed by a
field reversal to a negative field as the cloud moves overhead.
Figure 24: Approaching Thundercloud
Figure 25: Increasing Field due to Approaching Thundercloud