Why does a multimeter show infinite resistance when measuring a five-color ring resistor?
Use a multimeter to measure the five-color ring resistance. The displayed resistance value is infinite. The possible reasons are as follows:
1. The resistance is a high-resistance resistance of tens of MΩ or more. A general digital multimeter can only measure resistance below 20MΩ. If the measured resistance exceeds the maximum measurement range of the multimeter, the multimeter will display "1" (ie, overflow). You can first check whether the fourth color ring of the resistor is green or blue to confirm whether the resistor is a high-resistance resistor.
2. If the conductive film of the resistor being measured is open-circuited and damaged, the resistance value will not be measured, and sometimes the displayed resistance value will be infinite.
The color ring resistor is composed of a conductive film attached to a porcelain core, coated with a paint film, and printed with a color ring. If the conductive film on the resistor body falls off or is burned out due to high current, then use a multimeter to measure the resistance. The value will be infinite.
In addition, if the connection between the two pins of the resistor and the conductive film on the resistor body is cracked and disconnected, the resistance value of the resistor may also be infinite. When these two situations occur, the resistor cannot be used.
If the actual resistance of a resistor measured with a multimeter is infinite, you can first confirm whether it is a high-resistance resistor. If it is not a high-resistance resistor, you need to check whether the resistor body is blackened or whether the connection between the pin and the resistor body is loose. For some resistors, excessive current in an instant or mechanical impact will cause the resistor to open circuit and be damaged.
How to identify five-color ring resistors
On the color ring resistor, different colors of color rings are used to represent the sorting order of the color ring, generally: brown 1 red 2 orange 3 yellow 4 green 5 blue 6 purple 7 gray 8 white 9 black 0, gold and silver represent errors.
Color ring resistors are a widely used type of resistor in various electronic devices. No matter how the color ring resistor is installed, maintenance and repair personnel can quickly and correctly read its resistance value, making it easy to detect and replace.
