TA Instruments RSA-G2, Руководство пользователя

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RSA-G2 Getting Started Guide Page 56
Phase Angle Check
To check the phase angle using the RSA-G2, perform a Phase Angle and Modulus Check in TRIOS soft -
ware (refer to TRIOS Help for additional information).
The phase angle correction compensates for possible phase shifts that may be added to force and strain due
to instrument electronics. Once the correction is determined, it should remain constant for the life of the
system. The phase angle correction is computed and entered at the factory before the instrument is shipped,
and should not have to be adjusted under normal operating conditions.
Phase angle is checked at the time of installation and is recommended to be rechecked once a year during a
scheduled preventative maintenance visit. A 40-mm three-point bending geometry is required if you wish
to periodically check the phase angle or perform a phase angle calibration outside of a scheduled preventa -
tive maintenance visit.
Recall that a purely elastic sample has a phase angle of zero degrees. The phase angle of steel is near zero.
If the values obtained from this test are abnormal, please contact Technical Services for further assistance.
Force Calibration
Perform a Force Calibration using TRIOS software. Refer to TRIOS Help for additional information.
The force calibration ensures that the signal output by the transducer is properly scaled to normal force.
Recall that the actual transducer output is a voltage that is proportional to the applied normal force. In
order to correctly obtain a value for normal force, the software must convert from voltage to force using a
conversion factor (calibration coefficient). The calibration coefficient is determined by observing the trans -
ducer output voltage while applying a controlled known force, and calculating the correct conversion fac -
tor to report the applied force. The calibration coefficient is then used by the software to compute true
normal force during regular sample testing.
The calibration involves hanging precision weights on a calibration fixture, which is mounted on the trans
-
ducer during calibration. The applied normal force is the amount of weight applied to the calibration fix -
ture. For example, hanging a 2000 gram weight applies a normal force of 2000 gmf.