Detailed explanation of how to read and measure chip resistors

With the continuous development of electronic products,Chip resistorBecause of its small size and stable performance, it is widely used in various circuit boards. For electronic engineers and maintenance personnel, accurate reading of patchesresistanceMarking and correctly measuring its resistance are very important skills. This article will introduce in detail the reading and measuring methods of chip resistors to help readers better understand and apply this electronic component.

1. Overview of chip resistors

Chip resistors, also known as surface mount resistors (SMD resistors), usually use a three- or four-digit numerical code to indicate the resistance value. Due to their small size, traditional color circle markings are not suitable, so numerical codes become the primary method of identification. At the same time, the measurement of chip resistance requires the use of tools such as multimeters. Correct measurement methods can effectively determine whether the resistance is normal.

2. How to read chip resistors

1. How to read the three-digit code

A three-digit code is the most common way of identification, with the first two digits representing the significant digits and the third digit representing the multiplier. For example, for a chip resistor marked "103", the first two digits "10" are valid figures, and the third digit "3" means multiplying 10 to the third power, that is, 10×10^3=10,000Ω, which is 10kΩ.

2. How to read the four-digit code

Four-digit codes are typically used for higher-precision resistors, with the first three digits being the significant digits and the fourth digit being the multiplier. For example, "1001" means 100×10^1=1000Ω, which is 1kΩ.

3. Letter and code identification

Some chip resistors will add letters after the numerical code, such as "K" for kiloohms and "M" for megaohms, for quick identification. In addition, some special resistors will also have specific character codes, so you need to refer to the manufacturer's manual.

3. How to measure chip resistance

4. Use a digital multimeter to measure resistance

The most common method of measuring chip resistance is to use a digital multimeter. Adjust the multimeter to electrical resistance, and touch the probes to the two endpoints of the resistor to read the resistance value. It should be noted that the circuit should be disconnected during measurement to prevent other components from affecting the measurement results.

5. Measurement precautions

When measuring, make sure the probe is in good contact to avoid inaccurate readings caused by poor contact. At the same time, the resistance of the chip resistor is small. When measuring, you should avoid touching the resistor with your fingers to prevent static electricity or body temperature from affecting the measurement.

6. Use LCR meter to measure

The LCR meter can measure resistance, inductance, and capacitance with high measurement accuracy and is suitable for precise measurement of chip resistors. The operation method is similar, touch the probe to both ends of the resistor and read the resistance value.

7. Measurement fault judgment

By measuring the resistance value, you can determine whether the chip resistor is damaged. If the measured resistance value is significantly different from the nominal value, or shows an open circuit (infinite value), the resistor may have failed and needs to be replaced.

4. Other knowledge related to chip resistors

8. Identification of resistance tolerance

Chip resistors usually have different tolerances such as ±1% and ±5%. The smaller the tolerance, the higher the resistance accuracy. Tolerance information can generally be obtained through the code or packaging instructions.

9. Power identification of chip resistors

The power size affects the use range of the resistor. Common specifications include 1/8W, 1/4W and other specifications. Excessive power may cause the resistor to heat up or even burn out. Pay attention to the power level of the resistor when measuring.

Chip resistors are widely used in electronic equipment because of their small size and easy installation. Mastering the reading method of chip resistors, including the identification of three-digit and four-digit numerical codes, as well as letter identification, can help quickly determine the resistance value of the resistor. When measuring chip resistance, using a digital multimeter or LCR meter is a common and effective method. Pay attention to the measurement environment and operating skills to ensure accurate measurement. Through the introduction of this article, I believe readers can better understand and apply chip resistors and improve the maintenance and design efficiency of electronic products.