Many customers will ask about the specific differences between manganese zinc and nickel zinc when consulting products. Yirong Magnetism Industry will give a brief description:

Manganese-zinc ferrite magnetic rings and nickel-zinc ferrite magnetic rings are the two most widely used core components in soft ferrite. As we know, the U-shaped core, deflection core and E-shaped core used as output transformer in TV sets are generally made of manganese-zinc ferrite. The magnetic antenna used in radio can be either manganese-zinc or nickel-zinc, but it can be distinguished from different colors at the end of the rod. For example, some factories spray black paint on the end of manganese-zinc medium-wave magnets and large red paint on the end of nickel-zinc short-wave magnets. In addition, there are manganese-zinc and nickel-zinc ring cores.

But encounter smaller threaded, cylindrical, I-shaped and cap-shaped cores, some are made of manganese-zinc materials, others are made of nickel-zinc materials, and there is no color mark on the core. When these cores are mixed together, how to distinguish them? Here are two specific methods.

1. Visual measurement: Because the permeability of manganese-zinc ferrite rings is generally high, the grain size is large, and the structure is relatively compact, often black. In general, the permeability of Ni-Zn ferrite ring is low, the grain size is fine and small, and it is porous structure, often brown, especially when the sintering temperature is relatively low in the production process. According to these characteristics, we can use visual method to distinguish. Where the light is brighter, if the color of ferrite is black and the crystal is bright, the core is manganese-zinc ferrite; if the ferrite is brown, glossy and grains are not bright, the core is nickel-zinc ferrite. Visual measurement is a relatively rough method, which can be mastered through certain practice.

2. Testing method: This method is reliable, but it needs some testing instruments, such as high resistance meter, high frequency Q meter, etc.

1. The resistivity of manganese-zinc ferrite and nickel-zinc ferrite is different. Because the resistivity of manganese-zinc ferrite is relatively low, about 103_. cm, while that of nickel-zinc ferrite is relatively high, about 105-108_. cm. So we can measure it with a high resistance meter or any other instrument that can measure resistivity. Before testing, two electrodes at any position should be made on the magnetic core. For testing convenience, threaded, cylindrical and I-shaped ends of the two cylindrical cores can be selected as electrodes, while cap-shaped cores can be chosen as two electrodes on the same plane. At this time, the oxide layer of the magnetic core at the site to be measured can be gently ground with sand skin, and then coated with a material with good conductivity as the testing electrode, which can generally be used as 6B. The pencil is coated with two graphite electrodes and made into graphite electrodes as shown in the cylindrical and cap cores of Fig. 2. The resistivity of the pencil is measured when the DC voltage is over tens of volts. After two graphite electrodes have been made, the resistance of magnetic cores can also be distinguished between manganese-zinc ferrite and nickel-zinc ferrite by using a 500-type multimeter (range selector switch can be placed in 10K gear). Generally, manganese and zinc are below 150 K_, while nickel-zinc ferrite magnetic rings are fairly large and the multimeter head pointer is basically fixed.

2. We can also distinguish between manganese-zinc and nickel-zinc ferrite rings by using different frequency f. Because the frequency of manganese-zinc ferrite magnetic rings is generally below 2 MHz, its Q value is low, while that of nickel-zinc ferrite magnetic rings is between 2 and 200 MHz, its Q value is higher. We can use the existing high frequency coils, such as those shown in Figure 3 (when the inductance of the coil is less than 20 uH without a core), take out the core first, then load the ferrite core to be tested separately, and measure the Q value on the QBG-3 high frequency Q meter or other instruments with the same accuracy. The high Q value is nickel-zinc; the low Q value (usually several times lower) is manganese-zinc.