1. Wire wound resistors: general wire wound resistors, precision wire wound resistors, high power wire wound resistors, high frequency wire wound resistors.

2. Thin film resistors: carbon film resistors, synthetic carbon film resistors, metal film resistors, metal oxide film resistors, chemically deposited film resistors, glass glaze film resistors, metal nitride film resistors.

3.Solid resistors: inorganic synthetic solid carbon resistors, organic synthetic solid carbon resistors.

4.Sensitive resistors: varistor, thermistor, photoresistor, force-sensitive resistor, gas-sensitive resistor, humidity-sensitive resistor.

Main characteristic parameters

1.Nominal resistance: the resistance value marked on the resistor.

2.Allowable error: The percentage of the difference between the nominal resistance value and the actual resistance value and the nominal resistance value is called the resistance deviation, which represents the accuracy of the resistor.

The corresponding relationship between the allowable error and the accuracy level is as follows: ± 0.5% -0.05, ± 1% -0.1 (or 00), ± 2% -0.2 (or 0), ± 5% -Ⅰ, ± 10% -Ⅱ, ± 20% -Ⅲ

3. Rated power: Under normal atmospheric pressure of 90-106.6KPa and ambient temperature of -55 ℃ ~ + 70 ℃, the maximum power allowed for long-term operation of the resistor.

The rated power series of wire wound resistors is (W): 1/20, 1/8, 1/4, 1/2, 1, 2, 4, 8, 10, 16, 25, 40, 50, 75, 100, 150, 250, 500

The rated power series of non-wire wound resistors is (W): 1/20, 1/8, 1/4, 1/2, 1, 2, 5, 10, 25, 50, 100

4. Rated voltage: voltage converted from resistance and rated power.

5. Maximum working voltage: The maximum allowable continuous working voltage. When working at low pressure, the maximum working voltage is lower.

6. Temperature coefficient: The relative change of resistance value caused by each temperature change of 1 ℃. The smaller the temperature coefficient, the better the stability of the resistor. The resistance value increases with increasing temperature is the positive temperature coefficient, otherwise the negative temperature coefficient.

7.Aging coefficient: the percentage of the relative change in resistance of the resistor under a long-term load of rated power.It is a parameter that indicates the length of life of the resistor.

8.Voltage coefficient: within the specified voltage range, the relative change of the resistor is every time the voltage changes by 1 volt.

9. Noise: An irregular voltage fluctuation generated in the resistor, including two parts of thermal noise and current noise.The thermal noise is due to the irregular free movement of electrons inside the conductor, which makes the voltage of any two points of the conductor change irregularly .