Comparison Of Power Frequency Spark Tester And Other Types Of Spark Tester

The Power Frequency Spark Testing Machine is a kind of AC spark test machine, which is a voltage applied 50 times per second for the spark test opportunity, which is suitable for detecting the insulation performance of wires and cables on-line production. Power frequency spark tester generally adopts solid-state AC voltage regulation and single-chip microprocessor control technology, featuring high output stability, high detection sensitivity, no breakdown of breakdown count, strong anti-interference, obvious breakdown point, and breakdown. The number can be automatically counted and an alarm is generated.

1. AC spark test machine

(1) Advantages of AC spark tester

An New Spark Testing Machine ionizes the air surrounding the product to form an electric field. This corona is electrically conductive and provides a good test even when the electrode bead chain is not connected. Corona is generated when alternating current is turned from positive to negative in each cycle.

And because the corona near the wire product is hot, if we put a grounding cable in the electrode that is applied with the high-frequency electrode voltage for a while, we will find that the insulating part that is in contact with the corona has obvious heat. This heat helps to break through where the wire is insulated, otherwise the wire passes through the electrode and is not detected, as a result of subsequent spark tests and high voltage insulation tests will fail.

(2) Disadvantages of AC spark testing machine

For thinner insulated wires, the AC voltage ionizes the air in the foaming unit, which reduces the dielectric strength of the insulation. This insulation will fail and will eventually damage the product. Therefore, the high frequency spark machine is not applied to foam insulation and is very correct.

When the capacitance of the wire product in the electrode is particularly high, a leakage current will be formed. Because this capacitance is a function of the ratio of conductor size to insulation thickness, a very high capacitance is produced by the same electrode. For safety reasons, the spark generator's current output is limited to 4 to 6 mA. When the leakage current reaches this level, the spark will no longer be able to effectively output current to produce a high test voltage. For a certain wire, the maximum possible voltage that can be achieved will not be sufficient to provide a good test.

2. DC spark testing machine

(1) Advantages of DC spark tester

The DC spark tester produces almost no corona and heat, so it is a mild test method. The DC spark tester can be used for foaming and thin insulation. The DC spark tester technology has no problem for capacitors. Very large wires and wires with multiple conductors can be tested with one device. DC spark testers are often used for cabling, sometimes testing 25 pairs of cables in a single electrode.

(2) Disadvantages of DC spark testing machine

The wires of the DC spark tester must be grounded and the center conductor or shield must be grounded for safety and effectiveness reasons. If the ungrounded and broken wire passes through the electrode, the spark tester will count.

In the same test, the DC test voltage values are different compared to the AC voltage. This is not a real disadvantage, but the measurement of the two is different. The AC voltage is measured by the effective value and the DC voltage is measured by its peak value.