F.W. Bell 7030, Instruction Manual

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F.W. BELL Model 7030 Gauss/Tesla Meter Instruction Manual
Section 6 – Flux Density Measurement 6-7
AC MODE
ANALOG
FILTERING A low pass filter is available for each channel that may be set to pass
frequencies only below 50kHz, 5kHz or 500 Hz. The instrument can
automatically select the best filter setting based on the current flux density
being measured. The filters affect the displayed reading, and analog outputs.
Using the Autofilter
The autofilter uses hysteresis and will enable the filters according to
Table 6-3 .
Table 6-3 Auto Filter Switch Points
Detected Frequency Filter Enabled
Above 3 kHz 50 kHz
20 Hz-3kHz 5 kHz
Below 20 Hz 500 Hz
Note: When the frequency is indeterminate, as described under the
heading AC MODE OPERATION, the 5kHz filter is enabled.
Setting the Analog Filters
1) From the main menu, choose FILTER.
2) Position the “pointer” over the appropriate “selection” next to the
label “
Analog Filter
”.
3) Pressing the ENTER key advances the setting.
DC MODE
OPERATION In the dc mode, the presence of an ac component can lead to unstable
readings. If the peak value of the combined ac and dc component reach the
electrical limits of the instrument, even though the average dc level is within the
limits, an overrange condition will appear on the display. This situation can
also lead to erratic behavior if the automatic ranging feature is being used.
The presence of an ac signal can be verified by observing the analog output
signal or by using the ac mode to determine the magnitude of the ac
component. Analog outputs are discussed later in this section.