Keysight DAQ970A Guia Del Usuario página 109

5. Press Gage Settings, and use the knob or the front panel arrow keys to specify various strain gage settings.
Softkey
Gage Factor
Poisson Ratio
Excitation
Fix/ Ext
Excitation
Voltage
6. Press Integrate Settings softkey to select whether the measurement integration time will be specified in terms of
Number of Power Line Cycles (NPLC) or directly in seconds (Time). Only 1, 2, 10, 20, 100, and 200 PLC provide
normal mode (line frequency noise) rejection. Selecting 200 PLC provides the best noise rejection and res-
olution, but the slowest measurements.
Softkey
Integrate NPLC
Time
Keysight DAQ970A/DAQ973A User's Guide
Description
Gage factor is the ratio of the fractional change in resistance to the fractional change in length (strain)
along the axis of the gage. The larger the value, the more sensitive strain gage. Gage factor is a
dimensionless quantity. The typical value is approximately 2.
Specifies the Poisson ratio of the strain gage. Poisson ratio is defined as the negative ratio of the strain
in the transverse direction to the strain in the longitudinal direction.
Strain bridge conversions require the voltage of the external bridge excitation. For this voltage, you
can dedicate a multiplexer channel to measure the excitation voltage, or can specify a known fixed
voltage value. Fixed ( Fix ) - The fixed value specified by the Excitation Voltage softkey will be used for
the strain conversion. External (
used for subsequent strain bridge measurements that specify an external excitation voltage source.
Note that the external DCV reference channel must be a lower-numbered channel than the strain
channel.
Use the knob or the front panel arrow keys to specify the fixed excitation voltage applied to the bridge
by an external voltage source. This value will be used to convert strain bridge measurements on the
selected channel.
Description
Sets the integration time as 0.001, 0.002, 0.006, 0.02, 0.06, 0.2, 1, 2, 10, 20, 100, and 200 Power Line
Cycles (PLC). Only 1 PLC and longer times provide normal mode (line frequency noise) rejection.
Selecting 100 or 200 PLC provides the best noise rejection and resolution.
Directly sets the integration time in seconds.
Ext ) - DCV measurements on the enabled reference channel will be
3 Features and Functions
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