How to read voltage using an electric test pen
The digital display test pen is a kind of test pen, which belongs to the electrical and electronic tools, and is used to test whether the wire is charged. The pen body of the digital display test pen has an LED display, which can intuitively read the test voltage number. When measuring the fire wire, the lighting circuit has a voltage of about U=220V between the fire wire and the ground. The current (that is, the current passing through the human body) is very small, usually less than 1 milliampere. When such a small current passes through the human body, it will not harm people, and when such a small current passes through the neon bulb of the test pen, the neon bulb will emit light. .
Instructions for how to use the buttons:
(A key) DIRECT, direct measurement button (far away from the LCD screen), that is, when using the bit to directly touch the line, please press this button;
(B key) INDUCTANCE, inductive measurement button (closer to the LCD screen), that is, when using a bit to sense the contact line, please press this button.
Note: Regardless of how to print on the electric pen, please recognize that the one farther away from the LCD screen is the direct measurement key; the one closer to the LCD is the sensor key!
This testing pencil is suitable for direct detection of 12-250v AC and DC and indirect detection of neutral wire, phase wire and breakpoint of AC power. It can also measure the continuity of dead conductors.
Direct detection:
a. The last number is the measured voltage value;
b. When it is less than 70% of the high-cut display value, it will display the low-cut value;
c. When measuring direct current, touch the other pole with your hand;
Indirect detection:
Press and hold the B key, and bring the bit close to the power cord. If the power cord is charged, the high voltage symbol will be displayed on the display of the digital display pen.
Breakpoint detection:
Press and hold down the B key, and when moving vertically along the wire, the place where there is no display in the display window is the breakpoint.
The new digital display test pen can test 12V, 36V, 55V, 110V and 220V. Generally, press the top of the test pen to measure the voltage, and the highest display is the current test voltage value; the bottom is the induction test to detect insulators In the case of circuit breakage, this is based on experience.
Voltage detection:
1. The detection range is 12-250V AC/DC voltage.
2. Touch the direct measurement (DIRECT) button, and the metal front end of the test pen touches the object to be detected. The test pen is divided into five voltage levels: 12V, 36V, 55V, 110V and 220V. The last value on the LCD screen is the measured voltage value ( When it is less than 70% of the high-end display value, the low-end value is displayed).
3. When measuring non-ground direct current, the hand should touch another electrode (such as positive or negative).
Induction detection:
1. Lightly touch the induction, breakpoint measurement (INDUCTANCE) button, and the metal front end of the test pen is close to the object to be detected. If the "high voltage symbol" appears on the display screen, it means that the object is carrying alternating current.
2. When measuring a disconnected wire, lightly touch the induction, breakpoint measurement (INDUCTANCE) button, the metal front end of the test pen is close to the insulating outer layer of the wire, there is a disconnection phenomenon, and the "high voltage symbol" disappears at the breakpoint.
3. Use this function to easily distinguish zero and phase lines (the distance between lines should be increased when measuring parallel lines). Detect microwave radiation and leakage.
Precautions:
The buttons do not need to be pressed hard, and the two test buttons cannot be touched at the same time during the test, otherwise the sensitivity and test results will be affected.
