Differential flowmeter

Abstract

The invention discloses a differential flowmeter, which comprises a fixing rod. The fixing rod penetrates through a liquid flow tube along the diameter thereof and is fixed in the liquid flow tube, two opposite identical umbrella-shaped structures are arranged on the fixing rod in the liquid flow tube along the axial center direction of the liquid flow tube, each umbrella-shaped structure consists of a cone and a supporting cylinder, both the two supporting cylinders are provided with fiber bragg gratings with the same parameters, the same optical fiber is photoetched and processed by the aid of ultraviolet rays at intervals to form the two fiber bragg gratings, and the optical fiber is connected with an intensity demodulating device after leading out of the liquid flow tube, and then is connected with a data processing device. The differential flowmeter is simple in structure, and by the aid of stress difference of the two FBG (fiber bragg gratings) with the same structures on the optical fiber, self compensation of temperature and external influences is realized.

Description

technical field [0001] The invention relates to a differential pressure flowmeter. It belongs to flow measurement and detection technology. Background technique [0002] In the automation of industrial production process, flow is one of the parameters that need to be frequently measured and controlled. The earliest and most widely used flow sensor is the mechanical rotor type. Its technology is relatively mature, but due to the limitation of mechanical structure, the measurement error is large . The subsequently developed electromagnetic flowmeters, ultrasonic flowmeters and acoustic Doppler flowmeters all have high measurement accuracy and are easy to use, but are susceptible to electromagnetic interference and have high cost of use. Optical fiber flowmeter has the advantages of anti-electromagnetic interference, small size and light weight, etc., but the optical fiber flowmeter is designed by utilizing the modulation of flow rate on the intensity and phase of the optical...

AI Technical Summary

Problems solved by technology

These sensors are all designed through different mechanical structures, so that the change of flow velocity and the deformation and force acting on the structure maintain a certain mathematical relationship, and the FBG sensor pasted on the structure senses the deformation and force, thereby indirect measurement However, due to their structural design, it is difficult to guarantee the linearity between the flow measurement and the force of the structure, and it is seriously affected by temperature and external interference. Even if you want to eliminate the influence of temperature, you need an additional reference temperature sensor; although some structures The linear relationship is guaranteed and the accuracy is improved, but the structure is relatively complicated

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