How should the test pen be used?
The electric measuring pencil is almost one of the tools most used by electricians. For ordinary users, the electric measuring pencil that costs two yuan a piece has long been called one of the necessary tools for the family just like screwdrivers and pliers. But how should the test pen be used? Let's take a look.
Basic usage The various functions of the electric pen are inseparable from the correct method of use-for the electric pen, if the wrong method is used, there may even be a risk of electric shock, so be careful.
Here I will just talk about how to use the most common and cheapest neon bulb testing pencil: sandwich the insulating part of the testing pencil between the thumb, middle finger, ring finger, and little finger (the thumb is on one side, and the other three fingers are on the other. side), the index finger touches the metal cap or metal clip on the tip of the stylus.
On the other end of the test pen, there is a thing like a screwdriver, this part can only be in contact with the object to be tested, and must not be in contact with the human body.
When measuring, hold the electric pen in the above posture, and touch the measured object with the above-mentioned flat screwdriver part. At the same time, it is necessary to ensure that the measurer's body part is in contact with the ground (just stand on the ground directly, if wearing insulating rubber shoes or standing on a stool, you need to touch the wall with the other hand).
Measuring voltage Measuring voltage with the electric pen is the most common method of the electric pen. However, it should be noted that the electric test pen can only measure the presence or absence of voltage in the circuit, and cannot judge whether the circuit is on or off or the magnitude of the voltage (with voltage, it must be a circuit, but without voltage, it may not be an open circuit).
When measuring, touch the tested line with the electric test pen, if the electric test pen lights up, it proves that there is voltage in the line; otherwise, there is no voltage.
Before measuring, we must first know the purpose of our measurement. For example, in a single-phase circuit, the live wire has voltage under normal circumstances, and the neutral wire and ground wire have no voltage. Therefore, under normal circumstances, the live wire can light up the electric pen, but the neutral ground wire cannot light up. But when we measure the zero ground wire and the electric pen cannot be lit, it does not mean that the zero ground wire is completely normal, and further testing is required.
Distinguish between the neutral wire and the ground wire. Distinguishing between the zero and ground wires has always been a headache for many beginner electricians. But in fact, a test pen can solve this problem.
The electric measuring pencil is almost one of the tools most used by electricians. For ordinary users, the electric measuring pencil that costs two yuan a piece has long been called one of the necessary tools for the family just like screwdrivers and pliers. But how should the test pen be used? Let's take a look.
Basic usage The various functions of the electric pen are inseparable from the correct method of use-for the electric pen, if the wrong method is used, there may even be a risk of electric shock, so be careful.
Here I will just talk about how to use the most common and cheapest neon bulb testing pencil: sandwich the insulating part of the testing pencil between the thumb, middle finger, ring finger, and little finger (the thumb is on one side, and the other three fingers are on the other. side), the index finger touches the metal cap or metal clip on the tip of the stylus.
On the other end of the test pen, there is a thing like a screwdriver, this part can only be in contact with the object to be tested, and must not be in contact with the human body.
When measuring, hold the electric pen in the above posture, and touch the measured object with the above-mentioned flat screwdriver part. At the same time, it is necessary to ensure that the measurer's body part is in contact with the ground (just stand on the ground directly, if wearing insulating rubber shoes or standing on a stool, you need to touch the wall with the other hand).
Measuring voltage Measuring voltage with the electric pen is the most common method of the electric pen. However, it should be noted that the electric test pen can only measure the presence or absence of voltage in the circuit, and cannot judge whether the circuit is on or off or the magnitude of the voltage (with voltage, it must be a circuit, but without voltage, it may not be an open circuit).
When measuring, touch the tested line with the electric test pen, if the electric test pen lights up, it proves that there is voltage in the line; otherwise, there is no voltage.
Before measuring, we must first know the purpose of our measurement. For example, in a single-phase circuit, the live wire has voltage under normal circumstances, and the neutral wire and ground wire have no voltage. Therefore, under normal circumstances, the live wire can light up the electric pen, but the neutral ground wire cannot light up. But when we measure the zero ground wire and the electric pen cannot be lit, it does not mean that the zero ground wire is completely normal, and further testing is required.
Distinguish between the neutral wire and the ground wire. Distinguishing between the zero and ground wires has always been a headache for many beginner electricians. But in fact, a test pen can solve this problem.
Methods as below:
First, use an electric pen to measure the several wires in front of you. Only one wire can light up the electric pen, and this wire is the live wire.
Afterwards, hold an electric pen in each of the left and right hands, and the measurer stands on an insulating object, not in contact with the earth. Use one of the electric pens to touch the live wire, and the other electric pen to touch the line to be tested. If the two electric pens are not lit or the brightness is low at this time, the wire to be tested is the ground wire. If the two electric pens light up normally at this time, the line to be tested is the zero line.
Method 1: There are at least two wires in the circuit, measure with an electric pen, if one of the two wires can light up the electric pen, and the rest cannot light up, it proves that the circuit is AC. If there are two wires that can light up the electric pencil, it proves that the circuit is direct current.
Method 2: When the circuit is AC, the brightness of the electric pen is higher. When the line is DC, the brightness of the electric pen is low.
Method 3: Observe the light-emitting position of the electric pen. The same is to use the electric pen to touch the live wire. If it is direct current, the neon bulb inside the electric pen will only glow at one end; if it is alternating current, the neon bulb inside the electric pen will light up.
The neon bulb in the electric pen distinguishes the positive and negative poles. By observing the light-emitting position of the neon bulb, you can also know the positive and negative poles of the direct current at the same time.
