Arbiter Systems 1040C - Current Overload Test; Current Output Range Test; Current Source Test; Minimum Output Test

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2.8.3.6.4 Current Overload Test
The current overload test is performed in two steps. In the first step the test relay is closed and the
current source is energized. A compliance measurement is performed and should be less than a
prescribed limit. In the second step the test relay is opened with the current source energized and
the compliance voltage measurement is repeated. The compliance voltage measured should
exceed a prescribed value. A FAIL message is displayed if the test fails. NOTE: The current
output connections must be open for proper operation of this test.
2.8.3.6.5 Current Output Range Test
Each of the 5 current output ranges is tested for correct output at full-scale values. The current
output test relay is closed during the test to provide a current path for the output. Range 5, the
10A range, is tested at 2A. (The test relay contacts are rated at 2A.) The tests performed are the
lowest DC current range (range 1) at 1 mA full scale, then range 2 at 10 mA, and range 3 at 100
mA. High current ranges, range 4 at 1 A and range 5 at 2 A for the 10 A range, are tested for
correct output. This test also tests the current power converter, which supplies the high current
output amplifier.
The range test current outputs are measured and compared with an expected value. If the test
output value deviates from the expected value by more than a prescribed limit, a test failure
message for the range is displayed and corrective maintenance is required.
2.8.3.7 CURRENT SOURCE TEST
Current waveform generation and control circuitry is tested in this series of tests. The operation of
the digital to analog sinewave generator and the attenuator control circuits are exercised.
2.8.3.7.1 Minimum Output Test
The coarse and fine control attenuators, A1 and A2, are set for minimum output and the current
output is measured. If the output exceeds a prescribed limit a FAIL message is displayed and the
attenuator circuitry needs corrective maintenance.
2.8.3.7.2 Attenuator Test
To produce a prescribed set of output values the unit increments and decrements internal
attenuators to check the linearity of the attenuators. A FAIL message indicates that the linearity of
the control DAC is suspect and corrective maintenance is required.
2.8.3.7.3 Sinewave Test
The sinewave generator output at 60 Hz is tested. The measured output must agree with a preset
value, within a prescribed limit, in order to pass the test. A FAIL message indicates that the
sinewave generation ROM and DAC circuitry are suspect and in need of corrective maintenance.
The high current output amplifier is not used in this test.
2.8.3.8 VOLTAGE MEASUREMENT TEST
The voltage measurement circuitry is validated first and if correct results are obtained each of the
5 voltage output ranges are exercised for correct output at the maximum output value for each