Autozero; Ranging - Agilent Technologies Agilent E1412A User Manual

Autozero

Ranging

40 Agilent E1412A Multimeter Application Information
Autozero applies to dc voltage, dc current and 2-wire resistance
measurements. The multimeter internally disconnects the input signal
following each measurement and takes a zero reading when autozero is
enabled. Autozero enabled is the default setting. It then subtracts the zero
reading from the preceding reading. This prevents offset voltages present on
the multimeter's input circuitry from affecting measurement accuracy.
•
When autozero is disabled (
reading and subtracts it from all subsequent measurements. It takes a
new zero reading each time you change function, range or integration
time. You can disable autozero on dc voltage, dc current and 2-wire
ohms measurements only (it is always disabled for ACV and ACI
functions). Autozero is always enabled when you select 4-wire ohms
or ratio measurements.
•
The autozero mode is stored in volatile memory. The multimeter
automatically enables autozero at power-on and after a module reset.
•
Use the following command to disable autozero or select the
parameter. The
OFF
Autozero does not perform a new zero measurement. Autozero
OFF
ONCE performs an immediate zero measurement.
[SENSe:]ZERO:AUTO OFF|ONCE|ON
You can let the multimeter automatically select the range using autoranging
or you can specify a range. If you specify an expected value for the signal
you are measuring, the multimeter selects the range to accommodate the
expected input signal and turns autoranging off. Specify a range for faster
measurements to eliminate the autoranging time.
•
The multimeter has autorange mode enabled at power-on and after a
module reset.
•
Autorange thresholds:
Down range at <10% of range.
Up range at >120% of range.
•
The multimeter will provide an overload indication by returning
"9.90000000E+37"
range can measure and autoranging is disabled or at the maximum range
setting.
•
The multimeter uses one "range" for all inputs between 3Hz and
300kHz for the frequency and period functions. The multimeter
determines an internal resolution based on a 3Hz signal. If you query
the range, the multimeter will respond with
period measurements return
•
The specified range applies to the signal connected to the Input
terminals for ratio measurements. Autoranging is automatically
selected for reference voltage measurements on the Sense terminals.
•
You can set the range using any of the following commands:
CONFigure:< function
MEASure:< function >? <
function
[SENSe:]< >:RANGe <
function
[SENSe:]< >:RANGe:AUTO OFF|ON
), the multimeter takes one zero
OFF
and parameters have a similar effect.
ONCE
if the input signal is greater than the present
with no input signal applied.
"0"
> < range >|MIN|MAX|DEF,<
range >|MIN|MAX|DEF,<
range
>|MIN|MAX
ONCE
. Frequency and
"3Hz"
resolution >|MIN|MAX|DEF
resolution >|MIN|MAX|DEF
Chapter 2