AQ8920 FIBER OPTIC DISTRIBUTED TEMPERATURE UNIT *
The AQ8920 optical fiber distributive temperature measurement instrument uses optical time domain reflectometer (OTDR) technology. When an optical fiber is connected and light pulses are input, the AQ8920 detects the rear scattered light (Raman scattered light) and converts it to a temperature distribution. Because the temperature sensor consists of optical fiber, it is highly resistant to explosion.
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Details
Features
- Continuously measures temperature distribution over distances as long as 2 km with a sampling resolution of 50 cm
- Measures temperature distribution over distances as long as 1 km with a precision of ±1? per 10 seconds
- Instrument control through RS-232C interface
- Temperature measurement sample software included (compatible with Windows® 2000/XP)
Applications
- Temperature management for plant facilities
- Research and studies related to disaster prevention
- Air conditioning facilities in power stations and large-scale buildings
Example System Configuration
The basic system consists of a controller (PC, etc.), the AQ8920, and an optical fiber. The temperature measurement results are displayed on the controller (notebook PC).
| Controller | AQ8920 | Optical fiber |
| Controls the AQ8920 and processes measurement data. | Optical fiber distributive temperature measurement instrument which performs measurements while controlled by the controller. | Functions as a temperature detector. Must be installed so that the temperature from the measured object is transmitted to it efficiently. |
ght, and Brillouin scattered light. The AQ8920 uses Raman scattered light, which has the highest temperature dependence among these various light types. The temperature is measured and the scattered light is separated and received. Raman scattered light consists of anti-Stokes light, which occurs at the shorter wavelength end (relative to the wavelength of the light pulse), as well as Stokes light, which occurs at the longer wavelength end. The intensity ratio of these two components changes in proportion to changes in temperature. This characteristic can be used to measure temperature using optical fiber.
Light pulses are input to the measured optical fiber to measure the temperature distribution. The measured optical fiber is a 50/125 É m GI quartz multimode optical fiber.
It may be necessary to study the sheathing's heat withstanding ability and other factors, depending on the temperature environment where the optical fiber is installed, and environmental conditions such as whether the sheathing would be melted by the heat.
Screenshot of measurement display from evaluation software
Specifications
| Name | Description | File Type | |
|---|---|---|---|
| Bulletin AQ8920-00E | AQ8920 Fiber Optic Distributed Temperature Unit |  456 KB |
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