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Section 1
Introduction
Tester Description
The Model 933A Life Cycle Test System (LCTS) is a complete and ready to use piece of
test equipment for the endurance testing of materials and electrical switches. The LCTS
can be configured to continuously depress a test sample using a pneumatically
controlled cylinder. The Model 933A is designed to measure one electrical contact with
each up/down stroke according to ASTM Designation F1578 - 96. The LCTS can also
be used to mechanically stress a device without a contact measurement. In this case,
testing is performed at a fixed speed and there are no pass / fail results. The air pressure
to the cylinder can be adjusted to control the maximum force applied to the sample and
with the optional flow restrictors the rate at which this force is applied can also be
adjusted. The electrical contact can be tested for resistance and also bounce. Bounce is
measured using techniques described in the ASTM Designation F1661 - 96. These
measurements have tolerances assigned so that the LCTS can determine the pass / fail
status of each test cycle. A count is kept of all cycles, failures and sequential test
failures. These counts are compared against programmed limits to stop testing at user
defined events. For example, the testing can be stopped after 1,000,000 test cycles or
after 100 test failures.
The basic LCTS consists of:
Controller Unit
- containing the pneumatic air valves, pressure regulator,
pressure gauge, air couplings, electronics module and computer data
connector.
Power Module
- a wall mount power source.
Test Head
- consisting of the air cylinder, flexible air hose and quick disconnect
air coupling (with an adjustable slide post) and mounting hardware.
Test Stand
- an 8-inch base plate to which the Test Head slide post can be
mounted.
Data Cable
- a 20 foot cable with modular connectors on each end and a 9-pin
adaptor to attach to the user’s PC.
Application Software
- a single software application to communicate, control and
store data from the Controller Unit. This is provided on a CD.
