Voltage tester measures the presence of voltage in the line
This is one of the most commonly used functions of the stylus, i.e. holding the stylus in the correct position and touching the conductor with the tip of the stylus. When the pen lights up, it proves that there is voltage in the circuit, and when it does not light up, it proves that there is no voltage in the circuit.
However, in the actual use of the need to pay attention to, can not be alone through the electric pen bright and not bright to determine the normal or not of the circuit. For example, the unused state of the normal zero line and disconnected zero line, can not light up the electric pen, but the former is a normal phenomenon, the latter belongs to the fault. Another example, the normal state of the fire wire and misconnected zero wire, can light the pen, but the former is a normal phenomenon, while the latter is a fault.
Measurement of phase wires in phase or out of phase
Circuits that do not differentiate between wire colors can definitely cause headaches when it comes to maintenance. Single-phase circuits are fine, but if you encounter a three-phase circuit, it's a real headache!
However, the electric pen has a magical function that can easily help you measure the same phase or different phase of the phase wires.
To measure, hold an electric pen in each of your right and left hands and stand on an insulated object. Will be two pens at the same time touch the two wires, if the brightness of the two pens is lower, it indicates that the measurement of the two lines at this time for the same phase (are phase lines). If the brightness of the two pens is higher, it indicates that the measurement of the two lines for the different phase (a phase line a neutral line).
In this way, three phase wires and one neutral wire in a three-phase circuit can be quickly screened out.
Distinguish between alternating current and direct current
First, from the brightness of the distinction, the brightness of the electric pen to measure AC power, to be significantly higher than DC power.
Secondly, it is the location of the brightness of the pen that makes the distinction. The light emitting body of the pen, called a neon tube, is in the shape of a long strip. Measurement of alternating current, the whole neon tube will glow; while measuring direct current, neon tube only one end of the light.
Measuring the positive and negative poles of DC
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In the previous paragraph, we said, in the measurement of direct current, neon tube only one end of the light. At this point, you can determine the positive and negative poles of the power supply by the position of the neon tube.
Measurement of the positive terminal of the power supply, neon tube near the tip of the end of the light; measurement of the negative terminal of the power supply, neon tube away from the tip of the end of the light.
