Optical fiber temperature sensor for temperature monitoring during microwave oven heating

microwave oven (microwave oven), as the name suggests, is a modern cooking stove that uses microwaves to heat food. Microwave is a kind of electromagnetic wave. Microwave oven is composed of power supply, magnetron, control circuit and cooking chamber. The power supply provides about 4000 volts of high voltage to the magnetron, which continuously generates microwaves under the excitation of the power supply, and then passes through the waveguide system and is coupled to the cooking chamber. Near the inlet of the cooking chamber, there is a rotating stirrer, because the stirrer is a metal fan, which reflects the microwave in all directions after rotation, so the microwave energy can be evenly distributed in the cooking chamber, thus heating the food. The power range of microwave ovens is generally 500 to 1000 watts.

Microwave oven is a cooking apparatus that uses food to absorb microwave energy in the microwave field and heats itself. The microwave generated by the microwave generator in the microwave oven establishes a microwave electric field in the microwave oven chamber, and certain measures are taken to make the microwave electric field as evenly distributed as possible in the furnace chamber. Food is put into the microwave electric field, and its cooking time and microwave electric field intensity are controlled by the control center to carry out a variety of cooking processes.

In popular terms, microwave is a high-frequency electromagnetic wave, which does not produce heat in itself, there are microwaves everywhere in the universe and nature, but there are microwaves in nature, because the dispersion is not concentrated, it can not heat food. Microwave oven is the use of its internal magnetron, the electric energy into the microwave, at 2450MHz oscillation frequency to penetrate the food, when the microwave is absorbed by the food, the polar molecules in the food (such as water, fat, protein, sugar, etc.) are attracted to the speed of 2.45 billion times per second rapid oscillation, the macro performance of this oscillation is that the food is heated.

The principle of microwave heating is simply that when the microwave radiates to the food, the food always contains a certain amount of water, and the water is composed of polar molecules (the positive and negative charge center of the molecule, even if the external electric field does not exist is not coincident), and the orientation of this polar molecule will change with the microwave field. Due to this movement of polar molecules of water in food. And the interaction between neighboring molecules creates a friction-like phenomenon that increases the temperature of the water and, therefore, the temperature of the food. Food heated with microwave, because its interior is also heated at the same time, so that the whole object is heated evenly, heating speed is also fast. At a rate of 2.45 billion times per second, it heats up 5 centimeters of food, speeding up the molecules.

Three taboos when using microwave to heat food:

1, avoid heating meat to semi-cooked and then microwave oven heating: because in the semi-cooked food bacteria will still grow, the second time to microwave oven heating, due to the short time, it is impossible to kill all the bacteria, bacteria will breed, which will harm human health. Frozen meat should be defrosted in the microwave before being reheated into cooked food.

2, do not freeze meat that has been thawed by the microwave oven again: because meat has been thawed in the microwave oven, in fact, the outside layer of low temperature heating, at this temperature bacteria can reproduce, although refreezing can make its reproduction stop, but can not kill live bacteria. Therefore, meat that has been thawed in the microwave must be heated until well done if it is frozen in the refrigerator.

3, avoid fried food: because of the high oil content of fried food, and high temperature oil will splash and lead to fire. In case of accidentally causing a fire in the furnace, do not open the door, but turn off the power first, and then open the door to cool down after the fire is extinguished.

Use the microwave to heat food three things do not:

1, do not use ordinary plastic containers: use special microwave utensils to hold food in the microwave oven to heat, one is that hot food will deform the plastic container, and the other is that ordinary plastic will release toxic substances, pollute food and endanger human health.

2, do not use metal utensils: because of the iron, aluminum, stainless steel, enamel and other utensils placed in the furnace, the microwave oven will generate electric sparks and reflect the microwave when heating, both damaging the furnace body and heating uncooked food.

3, do not use closed containers: when heating liquid should use a wide mouth container, because the heat generated by food heating in the closed container is not easy to distribute, so that the pressure in the container is too high, easy to cause blasting accidents. Even when frying food with shell, it is necessary to Pierce the shell with a needle or chopsticks in advance, so as not to cause burst after heating, splash to dirty the furnace wall, or splash to hurt people.

Finally, an optical fiber sensor for temperature monitoring in microwave oven heating process is introduced, that is, optical fiber temperature sensor-FOT-L-SD and optical fiber temperature sensor-FOT-L-BA introduced from abroad by Industrial mining network. FOT-L-SD and FOT-L-BA are a class of fiber optic temperature sensors that are ideal for measuring temperature in extreme environments, such as low temperatures, nuclear environments, microwaves, and high intensity RF. FOT-L combines all the good features you would expect from an ideal sensor body. As a result, these sensors provide high precision and reliable temperature measurements, even in extreme temperatures and adverse environments.

The main features of both FOT-L temperature sensors are complete immunity to EMI and RFI, at the same time, their small size, built-in safety for hazardous environments, high temperature resistance, corrosion resistance and high accuracy. Based on fiber optic technology, the sensor is essentially immune to EMI and RFI. The light sensor is electrically inactive, so it does not emit or be affected by any type of EM radiation, whether it is microwave, RF or NMR.