B&K Precision 5491B - Manual - Manual (Page 20)

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3.3 Measuring Current
Model 2831E current measurement range: 2 mA, 20 mA, 200 mA, *2 A, *20 A
Model 5491B current measurement range: 5 mA, 50 mA, 500 mA, *5 A, *20 A
*Indicates range is available for manual range only. Auto range will not work when reading requires
setting to this range.
Maximum resolution: 100nA (on 2 mA range (on 5 mA range for model 5491B))
Current measurement is available in Auto range for the lower current measurements only.
Note:
For 2831E, readings that are below 200 mA using the low current measurement input can be set in auto
range. This means it will auto range between 2 mA, 20 mA, and 200 mA range. For readings above
200 mA, auto range is not available. Manual range must be used to read any readings higher than 200
mA. This means, for ranges 2 A and 20 A, only manual range is available. Additionally, the high
current measurement input must be used to obtain measurements in these two higher ranges.
For 5491B, readings that are below 500 mA using the low current measurement input (fuse protected up
to 500 mA max.) can be set in auto range. This means it will auto range between 5 mA, 50 mA, and
500 mA range. For readings above 500 mA, auto range is not available. Manual range must be used
to read any readings higher than 500 mA. This means, for ranges 5 A and 20 A, only manual range is
available. Additionally, the high current measurement input must be used to obtain measurements in
these two higher ranges.
3.3.1 Connections
Assuming the multimeter is under factory default conditions, the basic procedure to measure current is
as follows (users must use manual range for measurement, following step 3):
1. Connect test leads between 500 mA terminal (for lower current measurements) and COM terminal or
between 20 A terminal (for higher current measurements) and COM terminal.
2. Select DCI or ACI measurement function by pressing → or → .
3. Press toggles auto ranging. Note that auto range is only available for readings that are
below 200 mA (for 2831E) and 500 mA (for 5491B) and when using the 500 mA max. terminal and
COM terminal connections. For readings above these limits, only manual range is available and
the 20 A terminal and COM terminal must be used to obtain measurement results. If instrument
shows the AUTO annunciator on display, press again to turn off auto ranging mode and go into
manual range mode. Use the RANGE and keys to select a measurement range
consistent with expected current.
4. Connect test leads to the source as shown in Figure 3-2.
CAUTION: Do not apply more than 1 A, 250 V to the 500 mA input terminal or the fuse will be
blown. Use 20 A terminal to measure current higher than 500 mA(or 200 mA for model 2831E).
DCV ACV