Do you know the uses of measuring pens?
(1) It can be used for low-voltage nuclear phase measurement to determine whether any wires in the circuit are in phase or out of phase. The specific method is to stand on an object that is insulated from the ground, hold a measuring pen with both hands, and then test on the two wires to be tested. If the two measuring pens emit very bright light, the two wires are out of phase; On the contrary, it is in phase, which is judged based on the principle that the voltage difference between the two electrodes of the neon bubble in the measuring pen is directly proportional to its luminous intensity.
(2) It can be used to distinguish between alternating current and direct current. When using a test pen for testing, if both poles in the neon bubble of the test pen emit light, it is an alternating current; If only one of the two poles emits light, it is direct current.
(3) It can determine the positive and negative terminals of direct current. Connect the test pen to a DC circuit for testing, and the electrode with the neon bubble shining is the negative electrode, while the electrode without the neon bubble shining is the positive electrode.
(4) It can be used to determine whether the DC is grounded. In a DC system with insulation to ground, standing on the ground can be used to contact the positive or negative poles of the DC system with a measuring pen. If the neon bubble of the measuring pen is not lit, there is no grounding phenomenon. If the neon bubble lights up, it indicates grounding. If it lights up at the tip of the pen, it indicates positive grounding. If it shines on the finger end, it is negative grounding. However, it must be pointed out that in DC systems with grounding monitoring relays, this method cannot be used to determine whether the DC system is grounded.
Classification of measuring pens
Classify according to the level of measured voltage
High voltage testing pen: used for 10kV and above project operations, as a daily testing tool for electricians;
Low voltage measuring pen: used for detecting charged objects with a line voltage of 500V and below.
Weak current test pen: used for testing electronic products, with a general test voltage of 6v -24v. For ease of use, the pen often comes with a lead wire with a clamp at the end.
Classification by contact method
Contact test pen: A detection tool that obtains electrical signals by contacting a charged object. Usually in the form of a straight screwdriver, it can be used as a test pen and a straight screwdriver; Pen style, displaying measurement data directly in the LCD window.
Inductive test pen: It adopts inductive testing and does not require physical contact. It can check the voltage on control wires, conductors, and sockets, or check the open circuit position along the wires. It can greatly ensure the personal safety of testing personnel.
