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5-35
IM 701210-05E
Horizontal and Vertical Axes
5
5.17 Setting the Strain Measurement
Setting the Gauge Factor
You can set the gauge factor of the strain gauge.
Selectable range: 1.90 to 2.20 (the resolution is 0.01)
The gauge factor is a unique constant defined for the strain gauge. It is usually
described in the manual for the strain gauge. The gauge factor cannot be changed while
waveform acquisition is in progress.
Gauge Factor (K) when mV/V Is Selected
You can set the gauge factor to an arbitrary value on the DL750/DL750P. However, if
there is no specifications on the strain gauge transducer, set the gauge factor to 2.00. If
the gauge factor is not 2.00, e is derived within the DL750/DL750P using the following
equation.
e = (4/K)
×
(V/E) e:
Measured value of the strain gauge transducer [mV/V]
V:
Voltage measured on the bridge [V]
E:
Voltage applied to the bridge [V]
K:
Gauge factor
Setting the Bandwidth
See section 5.7, “Setting the Bandwidth.”
Execute Balancing
The unbalanced portion of the bridge resistance is automatically compensated. The
execution of balancing takes a few seconds.
Balance range:
±
10000
µ
STR (when set to
µ
STR)
±
5mV/V (when set to mV/V)
Inverting the Waveforms
See section 5.12, “Inverting Waveforms.”
Precautions to Be Taken When Making Strain Measurements
• Be sure to execute balancing when making strain measurements.
• Select a bridge voltage of 5 V or 10 V when the bridge resistance is 350
Ω
or more. If
a bridge voltage of 5 V or 10 V is applied when the bridge resistance is less than 350
Ω
, correct measurements will not be made.
• When using a strain gauge transducer, use a bridge voltage in the recommended
voltage range of the transducer.
• Correction cannot be executed if a strain gauge bridge (bridge head) or a strain gauge
transducer is not connected to the channel on which balancing is to be executed.
• If balancing fails on any of the specified channels, an error message and information
on the failed channel is displayed.
• If the power is turned ON, a new strain gauge is connected, or the measurement
range, bridge voltage, or gauge factor is changed, balancing must be performed again
before making measurements.
The scale value indicates “imbalance” immediately after power-up or when the range
is changed. In such case, execute balancing.
• When you switch the unit, the unit of all related parameters of the channel is switched
accordingly (upper and lower limits, trigger level, measured values of automated
measurement parameters, cursor measurement values, etc.).