IM 701240-01E
5-28
Explanation
Range Unit
The unit can be changed between “the strain unit (
×
10–6 strain):
µ
STR” and “the output
unit of the strain gauge transducer: mV/V.” The default value is
µ
STR. The following
equation is used to derive the mV/V range.
mV/V = 0.5
×
(
µ
STR/1000)
Range
Select from the following:
If
µ
STR Is Selected
500
µ
STR, 1000
µ
STR, 2000
µ
STR, 5000
µ
STR, 10000
µ
STR, or 20000
µ
STR
For the measurement range, see section 18.12.
If mV/V Is Selected
0.25 mV/V, 0.5 mV/V, 1 mV/V, 2.5 mV/V, 5 mV/V, or 10 mV/V
For the measurement range, see section 18.12.
The value that is indicated at the right side of the range display is the maximum input
at the current bridge voltage converted to volts. It indicates the maximum input voltage
at the selected range.
Display Range (Upper/Lower)
You can change the upper and lower limits of the display range according to the input for
easier viewing of the measured waveforms.
Selectable range:
–3.0000E+04 to +3.0000E+04 (when set to
µ
STR)
–1.5000E+01 to +1.5000E+01 (when set to mV/V)
Be sure the upper limit value (Upper) is greater than the lower limit value (Lower).
Bridge Voltage (Excitation)
You can select the voltage to be applied to the bridge head.
• 2V:
When the bridge head resistance (bridge resistance) is 120
Ω
to 1000
Ω
• 5V*:
When the bridge resistance is 350
Ω
to 1000
Ω
• 10V*:
When the bridge resistance is 350
Ω
to 1000
Ω
The bridge voltage cannot be changed while waveform acquisition is in progress.
*
The bridge voltage can be set to 5 V or 10 V only when the following conditions are met.
• The bridge resistance is greater than or equal to 350
Ω
.
• Strain gauge transducer that supports the bridge voltage of 5 V or 10 V.
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) If mV/V Is Selected
You can set the gauge factor to an arbitrary value on the SL1400. However, if there are
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 SL1400 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
5.15 Setting the Strain Measurement