19
the test. In either case, the unit will go through the usual test
sequence and will display a
DECAY TIME
reading that should be
within ±0.05 seconds of the value indicated on the
STM
System
Test Module. If the
DECAY TIME
reading is not within this
tolerance, the unit may be out of calibration, or may not be
functioning properly. The difference between
+
and
–
decay time
readings should be no more than 0.02 seconds. If this is the case,
contact ETS for assistance.
For the
STM-2
the decay time is typically between 0.20 and 0.30
seconds when held in place with the magnetic electrodes. Using
the clamp electrodes will result in a reading approximately 0.03
seconds lower. This is due to the electrode effect described in
Section 4.5. If the
DECAY TIME
reading is not within this
tolerance, the unit may be out of calibration, or may not be
functioning properly.
3.4 Electrode Configurations
3.4.1 Magnetic
Electrodes
Magnetic Electrodes are used to secure film and fabric samples plus the
STM-1 to the base electrodes as shown in Figure 3.4-1.
Figure 3.4-1: Magnetic Electrodes
3.4.2 Clamp
Electrodes
The Clamp Electrodes shown in Figure 3.4-2 are used to secure samples
that are up to one inch thick. Thicker samples can be tested using longer
¼-20 threaded rods.
Sample
Magnetic Electrodes
