Autorange
The default range is autorange. Autorange is the process where the
multimeter samples the input signal, and then automatically selects the
correct (lowest valid) range. Consider the following when using autorange:
1. Autoranging typically adds 150
µ
s to the fixed range measurement
time if it ranges up one range, or ranges down any number of ranges.
Each reading takes an additional 50
µ
s for each additional range-up
step. If autoranging is enabled but does not occur, approximately
100
µ
s is added to the fixed range measurement time. The
E1326B/E1411B automatically switches to the 10
µ
s aperture time
when making measurements to determine the correct range.
2. For maximum speed, group channels together which use the same
range. When the aperture time is 10
µ
s and autoranging is enabled
but does not occur, the measurement rate is 2380 readings/second.
3. Use autorange to simplify thermocouple, thermistor, and RTD
measurements.
Setting Autorange
Autorange is set when
AUTO
,
DEF
, or no range parameter is specified in the
MEASure
or
CONFigure
command. Autorange is also enabled and disabled
with the low-level commands:
VOLTage:RANGe:AUTO
mode
RESistance:RANGe:AUTO
mode
where:
mode
= ON
(turns autorange on) or
OFF
(turns autorange off).
Querying the Range
The measurement range is queried with the following commands:
VOLTage:RANGe?
VOLTage:RANGe? MIN | MAX
VOLTage:AC:RANGe?
VOLTage:AC:RANGe? MIN | MAX
RESistance:RANGe?
RESistance:RANGe? MIN | MAX
Executing
CONFigure?
returns the range, resolution, and measurement
function set by the
CONFigure
command.
Note
When querying the range, the ranges available with the range command
(Table 4-5) are returned. For example, if a range of 0.113 V is set with the
MEASure
or
CONFigure
command, 0.125 is returned if the range is queried.
If 0.91 V is set, 1.0 is returned, and so on.
94 Understanding the HP E1326B/E1411B Multimeter
Chapter 4
Artisan Technology Group - Quality Instrumentation ... Guaranteed | (888) 88-SOURCE | www.artisantg.com