The principle of distributed fiber temperature measurement system is based on the reverse Raman scattering effect. The laser pulse interacts with the fiber molecules and scatters. There are many types of scattering, such as Rayleigh scattering, Brillouin scattering, and Raman scattering. Among them, Raman scattering is due to the thermal vibration of the fiber molecules, which produces a light longer than the wavelength of the light source, called Stokes light, and a light shorter than the wavelength of the light source, called anti-Stokes ( Anti-Stokes) light. The optical fiber is modulated by the external temperature to change the anti-Stokes light intensity in the fiber. The ratio of Anti-Stokes to Stokes provides an absolute indication of temperature. This principle can be used to realize the temperature field along the fiber. Distributed measurement.
Distributed fiber temperature measurement system uses high-quality pulse light source, light receiving equipment and high-speed signal acquisition and processing technology to obtain accurate temperature values ​​along all points of the fiber. It is the best performance and advanced technology of distributed fiber temperature measurement system. The temperature can be measured for a distance of up to 30 km and a spatial resolution of 1 m, which is equivalent to 30,000 measuring points. According to the actual project size, the user can select the corresponding product model.
Compared with traditional sensors, the distributed optical fiber temperature measurement system has many natural advantages, including:
1) Continuous distributed measurement
The distributed optical fiber sensor is a true distributed measurement, and it can continuously obtain measurement information along several tens of kilometers of the detection optical fiber. The false alarm and false alarm rate are greatly reduced, and real-time monitoring is realized at the same time.
2) Anti-electromagnetic interference to achieve on-site power-free detection.
The optical fiber itself is composed of quartz material and is fully electrically insulated. At the same time, the signal of the optical fiber sensor is based on an optical signal, which is intrinsically safe and free from any external electromagnetic environment. The tank area can enter the field without electricity, thus eliminating the danger of generating sparks in the area containing combustible gas mixture, enabling on-site electricity-free detection and intrinsically safe.
3) Intrinsic lightning protection.
Lightning often destroys a large number of electrical sensors. Optical fiber sensors are fully electrically insulated and can withstand high voltage and high current surges.
4) Far distance measurement, suitable for remote monitoring.
The two outstanding advantages of optical fiber are the large amount of data transmitted and the small loss. It can realize remote monitoring of several tens of kilometers without relaying.
5) High sensitivity and high measurement accuracy.
Theoretically, most optical fiber sensors have better sensor sensitivity and measurement accuracy than general sensors. Actually mature products have also proved this.
6) Long life, low cost and simple system.
The material of the optical fiber is generally quartz glass, which has the characteristics of non-corrosion, fire resistance, water resistance and long life, and can usually serve for 30 years. Considering the cost of the sensor itself and the maintenance cost later, the use of fiber-optic sensors can greatly reduce the final operating cost of the entire project. This monitoring system belongs to the current ideal technical equipment in the petrochemical industry.
It is precisely because of these advantages of distributed optical fiber temperature measurement system that it also makes the product has a wide range of applications
â—† On-line temperature detection and over-temperature alarm for underground or overhead high-voltage cables.
â—† Temperature distribution measurement and overheating alarm of large and medium-sized transformers.
â—† Substation environmental temperature detection and fire alarm.
â—† Temperature distribution measurement, fault diagnosis and overheating alarm of generator set.
â—† Fire prevention and temperature alarm in coal mines and tunnels.
â—† Temperature monitoring and alarms for oil depots, grain depots, dangerous goods stores, cold stores and other warehouses.
â—† Temperature distribution measurement and overheating alarm of large and medium-sized transformers.
â—† Temperature alarm system for large cargo ships and tankers.
â—† Temperature detection and over-temperature alarm of various power network of power plants.
â—† Temperature detection and over-temperature alarm for various large and medium-sized oil pipelines.
â—† Dynamic temperature detection of chemical materials, photographic materials, foods and other production processes.
â—† Temperature detection and fire alarms in smart buildings and general civil buildings.
Doup Wire,Leno Doup Healds,Doup For Weaving Machinery,Plastic Doup Heald
Transally weaving accessories Co., Ltd , https://www.transally-co.com