Model 4431T Shielded Bag Test System - Operating Manual
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D00003 Rev. K.
5.6 Power up all instruments.
5.7 Set the FUNCTION select switch to
AUTO nJ
if the test is to be controlled by the computer
(Automatic Continuous Testing), or
MAN nJ
if not (Manual or Automatic Monitored Testing).
5.8 For waveform verification in the MAN mode, set the oscilloscope VERTICAL sensitivity to 500mV,
the time base to 100nsec and the trigger level to 500mV. For bag testing start with settings of 20
or 50mV, 20nsec and 50 or 75mV respectively. Note that these settings are necessary only for Manual
Testing. For Automatic Testing the computer automatically sets the correct scope parameters, for typical
“good” bags. If the waveform extends off the scope screen, the vertical scale must be manually
adjusted so that a complete waveform is displayed.
6.0 ENERGY TESTING – MANUAL MODE
This chapter covers the details of manual product testing per ANSI/ESD S11.31 – Energy Test, using
only the 4431 Discharge Unit and the Oscilloscope. Data can be saved from the USB port of the scope
for later processing by user software (not supplied). See the next chapter on AUTOMATIC ENERGY
TEST for automated control of this test.
6.1 Test Waveform considerations.
ANSI/ESD STM11.31 requires verification of the discharge current pulse both through a short to ground
and through a 500 Ohm resistor. See Appendix A for the details of the verification process. The
waveform is carefully set up at the factory and should require minimal maintenance. Below is a plot of a
typical discharge pulse.
Fig. 6-1. Calibration Waveform
6.2 Sample sizes
ANSI/ESD S11.31 specifies an 8" x 10" bag size (20 x 25 cm) with the capacitive sensor placed in the
center. The Model 4431 incorporates adjustable stops to correctly locate 4", 6", 8" and 10" bag
lengths (10, 15, 20, and 25 cm). For the standard size bag insert the two red plastic stops into the third
hole from the front of the unit.
A test bag i s i n s e r t e d by sliding it over the capacitive sensor until it hits the stops, making certain
that the sensor is inside the bag. Center the bag laterally as shown in Figure 6-2.
