The multimeter is also called a multi-meter, a three-meter, and a multiplex table, and is divided into a pointer type multimeter and a digital multimeter. The multimeter consists of three main parts: the meter head, the measuring circuit and the changeover switch. It is a multi-functional, multi-range measuring instrument and a necessary testing tool in electronic production. It has a variety of functions such as measuring current, voltage and resistance. Among them, the digital multimeter has become the mainstream because of its high sensitivity, high precision, clear display, strong overload capability, and easy to carry and use.
There are many types of multimeters and different shapes, but the basic structure and usage are the same. The following explains the structure and usage of the multimeter and teaches you how to use the multimeter correctly. The universal surface board mainly has a head and a selector switch, as well as an ohmic zero adjustment knob and a test lead jack. The functions of each part are described below:
(1) Header
The meter's meter head is a sensitive galvanometer. The dial on the meter is printed with a variety of symbols, tick marks and values. The symbol A - V - Ω indicates that this meter is a multimeter that can measure current, voltage and resistance. There are a number of tick marks printed on the dial, and the right end marked with "Ω" is the resistance tick mark, the right end is zero, the left end is ∞, and the scale value distribution is uneven. The symbol "-" or "DC" means direct current, "~" or "AC" means alternating current, and "~" means a tick mark shared by alternating current and direct current. The number of lines below the tick mark is the scale value corresponding to the different gear positions of the selector switch.
There is also a mechanical zero adjustment knob on the meter head to correct the pointer to the zero position on the left end.
(two) selection switch
The multimeter's selector switch is a multi-position rotary switch. Used to select measurement items and ranges. (Figure 3 - 4 (B)). Typical multimeter measurement items include: “mAâ€; DC current, “Vâ€: DC voltage, “Vâ€: AC voltage, “Ωâ€: Resistance. Each measurement item is divided into several different ranges for selection.
(3) test leads and test lead jacks
The test pen is divided into red and black. When using, insert the red test lead into the jack marked with “+†and the black test lead into the jack marked “-â€.
The specific use of the multimeter:
[NT:PAGE]Before using the multimeter, you should do the following:
1. The multimeter is placed horizontally.
2. Check that the hands stop at the zero position at the left end of the dial. If there is a deviation, use a small screwdriver to gently turn the mechanical zero adjustment knob on the meter head to zero the needle.
3. Insert the test leads into the test lead jack as described above.
4. Rotate the selector switch to the corresponding item and range and it will be ready for use.
Measuring voltage: When measuring voltage (or current), select a good range. If you use a small range to measure large voltage, there is a danger of burning the watch. If you use a large amount of process to measure small voltage, the pointer deflection is too small to read. The range should be chosen to deflect the pointer to about 2/3 of the full scale. If you do not know the magnitude of the voltage to be measured beforehand, you should first select the highest range and then gradually reduce it to the appropriate range.
AC voltage measurement: put one switch of the multimeter in the AC and DC voltage, and the other switch is placed on the appropriate range of the AC voltage. The multimeter's two test leads and the circuit under test or load can be connected in parallel.
DC voltage measurement: put one switch of the multimeter in AC and DC voltage, the other switch is placed on the appropriate range of DC voltage, and the “+†meter (red meter) is connected to the high potential, “-†The test pen (black pen) is connected to the low potential, that is, the current flows from the "+" meter pen and flows out from the "-" meter pen. If the test leads are reversed, the pointer of the watch will deflect in the opposite direction, which is easy to bend the pointer.
Measuring current: When measuring DC current, put one switch of the multimeter in DC current block, and the other switch is placed on the appropriate range of 50uA to 500mA. The current range selection and reading method are the same as voltage. The circuit must be disconnected first, and then the multimeter is connected in series to the circuit under test according to the current from "+" to "-", that is, the current flows from the red meter pen and flows out from the black meter pen. If the multimeter is connected in parallel with the load, the internal resistance of the meter head is small, which may cause the short circuit to burn the instrument. The reading method is: actual value = indication value × range / full deviation
Measuring resistance: When measuring resistance with a multimeter, the following methods should be used:
Choose the right override. The scale of the multimeter's ohmic gear is not uniform, so the selection of the override gear should be such that the pointer stays in the thinner part of the scale, and the closer the pointer is to the middle of the scale, the more accurate the reading. Under normal circumstances, the pointer should be pointed between 1/3~2/3 of the scale.
Ohm zero adjustment. Before measuring the resistance, short the two test leads and adjust the “ohmic (electrical) zero adjustment knob†so that the pointer just points to the zero position to the right of the ohmic scale. If the pointer cannot be adjusted to zero, the battery voltage is insufficient or there is a problem inside the meter. And every time you change the override gear, you must perform ohms zero again to ensure accurate measurement.
Reading: The reading of the meter is multiplied by the magnification, which is the resistance of the measured resistance.
[NT:PAGE]After the multimeter is used, it should be done:
1. Pull out the test leads.
2. Turn the selector switch to the “OFF†position. If there is no such gear, it should be rotated to the maximum range of the AC voltage, such as “1000Vâ€.
3. If it is not used for a long time, the battery inside the watch should be taken out to prevent the battery electrolyte from leaking and corroding the internal circuit.
Notes on the use of the multimeter:
(1) Before using the multimeter, perform “mechanical zeroingâ€, that is, when there is no measured power, the multimeter pointer points to the zero voltage or zero current position.
(2) In the process of using the multimeter, the metal part of the test pen cannot be touched by hand, so that the measurement can be ensured on the one hand, and the personal safety can be ensured on the other hand.
(3) When measuring a certain amount of electricity, it is not possible to shift gears while measuring, especially when measuring high voltage or large current. Otherwise, the multimeter will be destroyed. If you need to change gears, you should first disconnect the test leads and then change the gears before measuring.
(4) When the multimeter is used, it must be placed horizontally to avoid errors. At the same time, we must also pay attention to avoiding the influence of external magnetic field on the multimeter.
(5) When the multimeter is used, the switch should be placed at the maximum of the AC voltage. If it is not used for a long time, the battery inside the multimeter should be taken out to prevent the battery from corroding other devices in the watch.
Well-known brand of multimeter - Dongqi Instrument ("TOKY")
Chengdu Dongqi Instrument & Electromechanical Co., Ltd. specializes in the development and production of high-performance, low-loss high-quality instrumentation products, as well as sales and sales of instrumentation products. After years of development and accumulation, it has become a well-known enterprise in the domestic instrumentation industry. Its trademark "TOKY" brand has become a well-known brand in the domestic automation field.
"Dongqi Instrument" products include: digital multimeter, digital clamp meter, display control instrument, pressure meter, temperature meter, flow meter, level meter, analytical instrument, coating thickness gauge, ultrasonic thickness gauge, gas Detectors, environmental testing instruments, Leeb hardness testers and other testing instruments, and in 2002 passed the ISO2001: 2000 international quality management system certification. At the same time, the related series of products developed and produced by the company have passed the CMC (Metrics Approval) certification and obtained the CE certification for compliance with the EU safety certification mark.
Outstanding brand, applicable products, and active marketing, Chengdu Dongqi Instrument & Electromechanical Co., Ltd. will continue to adhere to the concept of “Honesty and Trustworthiness, Excellence, Service First, Customer Firstâ€, adhere to the one-person-oriented, one-brand goal. Market-oriented, service-oriented, and guided by our new and updated ideas, we will provide you with updated and higher products.
Products Recommended:
First, Chengdu handheld four and a half multimeter MY65
Edit Comment:
â— Display mode: 41/2 digit LCD display
â—Data retention
â—Full function overload protection
â— continuity test / diode test / hFE test
â—Power supply: 9V (6F22)
Contact: Soup Manager
Contact number, 13981961978
Dealer: Chengdu Dongqi Instrument & Electrical Co., Ltd.
Address: Gate 8 of Hall 8 of Wanguan Hardware & Electrical Market, No. 555 Jinfu Road, Jinniu District, Chengdu.
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Edit Comment:
The MS8217 digital multimeter adopts the world's recognized “Santoprene TPE†material for over-molding 20%. The instrument not only adopts SMT technology, but also adopts multi-layer printed circuit board to make the instrument performance more reliable and stable.
The MS8217 digital multimeter series pays more attention to the personal safety of the instrument operator. It not only has both electronic and mechanical protection, but also the input range and function protection can be as high as 1000V (current range protection is 600V).
Contact: Soup Manager
Contact number, 13981961978
Dealer: Chengdu Dongqi Instrument & Electrical Co., Ltd.
Address: Gate 8 of Hall 8 of Wanguan Hardware & Electrical Market, No. 555 Jinfu Road, Jinniu District, Chengdu.
[NT:PAGE] 
Edit Comment:
Comply with international safety standards IEC1010-1CATII1000V&CATIII600V
Maximum display: 1999
Data retention function, automatic shutdown function
Background light display, full symbol display
Full gear anti-burning table protection
Built-in self-recovery fuse protection
Contact: Soup Manager
Contact number, 13981961978
Dealer: Chengdu Dongqi Instrument & Electrical Co., Ltd.
Address: Gate 8 of Hall 8 of Wanguan Hardware & Electrical Market, No. 555 Jinfu Road, Jinniu District, Chengdu.
Please contact us when you contact us. We will give you the best discount!
For more product and brand information, you can visit the Wantong Hardware Machine Grid.
Concerned about surprises
Label: scale value pointer deflection diode test three-meter temperature instrument
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