CN1084655A - Temperature measuring controller with optical-fibre sensor - Google Patents

Abstract

A kind of new temperature measuring controller with optical-fibre sensor is proposed, be by transducing head, optical cable, control box, camera lens closely, fibre-optical probe, biography resembles bundle, wind cover and water jacket and computing machine are formed, the present invention adopts the full-optical fiber optical formula, be that head does not have any electronic devices and components relevant with signal, the transmission of employing optical cable, improved anti-electromagnetic interference capability greatly, the transducing head volume-diminished, particularly tested distance changes, the temperature demonstration remains unchanged, make easy to installly, the present invention can be widely used in smelting, steel rolling, sintering, high-frequency welding, the commercial production occasion of non-contact measurements such as quenching control high temperature.

Description

Temperature measuring controller with optical-fibre sensor

The present invention is a kind of device that adopts the Fibre Optical Sensor mode to measure and control temperature, it is the energy measurement temperature both, can control temperature or other physical quantity again, the commercial production occasion of be widely used in smelting, non-fits such as steel rolling, sintering, high-frequency welding, high frequency heat processing being measured the control temperature.

Existing infrared thermometer is with photoelectric conversion section and before put part places in the head shell, adopts cable transmission to signal processing then, and transmission range is restricted like this, and anti-electromagnetic interference capability is low, and simultaneously, head volume is bigger.General infrared thermometer adopts the dual wavelength wide-band ratio or one wide one narrow relative method, and resolution is not high, and in addition, this temperature measurer receives wavelength more than 0.78 μ m, has limited about 4000 ℃ high temperature measurement.

The objective of the invention is to propose a kind of new temperature measuring and controlling instrument, the transducing head that adopts ordinary optical, variable refractivity optics, fibre-optic waveguide to form, carry out dual-wavelength measurement, make temperature measurer have advantages such as anti-electromagnetic interference capability, head volume is little, easy to install, resolution is high, temperature-measuring range is wide.

The invention is characterized in: it by transducing head, optical cable, control box, closely camera lens (contactless distance is 0.2 meter～1 meter), fibre-optical probe, biography resemble bundle, computing machine is formed, and adopt the dual wavelength arrowband relatively, can be λ ₁, λ ₂Value is in visible-range or infra-red range, or the both has, and the present invention is divided into 600 ℃～3000 ℃ to temperature-measuring range, 1500 ℃～4000 ℃; And λ ₁, λ ₂The value difference, the former is λ ₁Be 0.76～0.90, λ ₂Be 0.96～1.1; Latter λ ₁Be 0.6～0.70, λ x is 1.0～1.1, and Δ λ half-breadth 120 use the PIN detector.If below 600 ℃, must change sensitive detection parts and light path.

Transducing head of the present invention is by object lens (contactless distance is 1 meter～12 meters), optical gate, standard school zero light source, GRIN Lens, λ ₁And λ ₂Saturating visible beam splitter, graticule, eyepiece, visible light beam splitter, optical fiber, thermometer bulb and before put divider and form.The present invention is according to Planck law: $R={({\mathrm{\λ}}_2/{\mathrm{\λ}}_1)}^5\exp \left[\frac{C_2}{T}(\frac{1}{{\mathrm{\λ}}_1}-\frac{1}{{\mathrm{\λ}}_2})\right]$ R is the radiation energy value in the formula, C ₂Be second radiation constant, λ ₁And λ ₂Be known wavelength, T is a dut temperature.Two train wave λ from the thermal source radiation ₁And λ ₂After the object lens reception, again by anti-λ ₁, λ ₂, saturating visible beam splitter reflection, be focused on the GRIN Lens end face, imaging simultaneously can be to the quasi-thermal source measured point from eyepiece on graticule, it is a telescopic system, GRIN Lens and object lens are also formed a telescopic system, received λ simultaneously ₁And λ ₂Transfer to photoelectric conversion section by optical fiber and interference filter, when dut temperature raise or descend, the Bomi degree changed, and corresponding energy also changes thereupon.As can be known, temperature variation and emissivity and range-independence are a kind of gray-body radiations because the overwhelming majority is used from formula, and ε is the function of temperature, at λ ₁And λ ₂The energy of two train wave density is cancelled each other in relatively, but along with distance increases, tested thermal source width increases thereupon, and constant in order to keep width, system increases by a sensor again, and it is made up of visible light beam splitter and double detector.If the thermal source measured diameter is d: then $d=\frac{1}{K_1\·K_2}\ln \frac{I_1}{I_2},$ I when from double detector, getting variable in distance ₁/ I ₂, while K ₁, K ₂Be constant, obtain a curve thus,, guaranteed the change of tested distance, temperature-resistant in same minizone along with the variation of tested distance compensates automatically.

The present invention adopts the dual wavelength arrowband relatively, can be λ ₁, λ ₂Value is in visible-range or infra-red range, or the both has, and therefore, the present invention is divided into 600 ℃～3000 ℃ to temperature-measuring range, and 1500 ℃～4000 ℃, and λ ₁, λ ₂The value difference, the former is λ ₁Be 0.76～0.90, λ ₂Be 0.96～1.1, latter λ ₁Be 0.60～0.70, λ ₂Be 1.0～1.1, Δ λ half-band width 120A adopts the PIN detector.

The present invention places transducing head apart from the place of 1～12 meter of thermal source, observe measured target from eyepiece, can fix after aiming at the mark, if the measured target distance is between 0.2～1 meter, should use closely camera lens instead, if thermal source is in crawl space, or, should use the object lens of transducing head instead fibre-optical probe by peripheral its internal temperature of measuring.If meet rugged surroundings, as fog, dust and high temperature impact occasionally, the present invention can be connected with wind cover, water jacket protective device; dry and water-cooled; or, can reach the purpose of protection head object lens by 1 atmospheric pressurized air, reduce influence to measuring accuracy.If transducing head places eminence, during object observing inconvenience, this device can be connected with optical fiber facsimile beam, and its long 1.5 meters, the operator can stand in lower by optical fiber facsimile beam and observe measured target.By the communication interface at control box rear, can be sent to central control room (CCR) to output signal, connect computing machine, can observe or write down temperature variation curve at any time.

The present invention is easy for installation, after head is fixing, starts the self check button in control box, and optical gate is closed, and standard lamp is lighted, and temperature is presented at 1100 ± 10 ℃, and the expression system is normal, decontrols button, and system can connect λ automatic control loop.

Signal Processing of the present invention is to adopt single-chip microcomputer to carry out intellectuality to handle, design temperature arbitrarily in temperature-measuring range, specification error is ± 2 ℃, when reaching design temperature, alerting signal takes place on the one hand, signal offers corresponding topworks on the other hand, makes its control temperature or other physical quantity.The characteristics of signal Processing are to have increased the range correction button, and promptly dut temperature is constant in the distance of regulation, and tested interval is constant, and the correction of emissivity has simultaneously also played corresponding booster action.When same thermal source, after the disposable correction, or else with changing stability, control accuracy error＜0.5%.

The present invention adopts the full-optical fiber optical formula, promptly transducing head without any with the related electronic devices and components of signal, adopt the optical cable transmission, improved anti-electromagnetic interference capability greatly, head volume is little, and is easy for installation.The present invention by interference filter, obtains λ with received spectrum ₁And λ ₂The energy of two train waves compares, and makes the variation of its energy only relevant with temperature, and resolution is improved.The present invention adopts water jacket, wind cover protective device, camera lens (0.2 meter～1 meter) closely, and fibre-optical probe, replacement equipment or utility appliance such as optical fiber facsimile beam have increased function, have enlarged usable range.

Accompanying drawing 1 is a Fibre Optical Sensor high temperature measurement controller structural representation.Fig. 2 is a Fibre Optical Sensor high temperature measurement controller head construction synoptic diagram.

In the drawings, 1 is transducing head, and the contactless distance of its camera lens is 1～12 meter; 2 is optical cable, and 3 is control box, and 4 is water jacket, wind cover protective device, and 5 are camera lens closely, and contactless distance is 0.2 meter～1 meter; 6 is fibre-optical probe, and 7 for biography resembles bundle, and 8 is computing machine, and 9 is object lens; 10 is optical gate; 11 is standard school zero light source; 12 is GRIN Lens; 13 is λ ₁, λ ₂Saturating visible beam splitter; 14 is graticule; 15 is eyepiece; 16 is the visible light beam splitter; 17 is optical fiber; 18 is thermometer bulb; 19 put divider before being.

Claims (6)

1. temperature measuring controller with optical-fibre sensor is characterized in that by transducing head, optical cable, control box, closely camera lens (contactless distance is 0.2～1 meter), fibre-optical probe, biography resemble bundle, water sleeve wind cover protective device and computing machine and form; Adopt the dual wavelength arrowband relatively, λ ₁, λ ₂Value is in visible-range or infra-red range, or the both has; And temperature-measuring range is divided into 600 ℃～3000 ℃, 1500 ℃～4000 ℃, and λ ₁, λ ₂The value difference, the former is λ ₁Be 0.76～0.90, λ ₂Be 0.96～1.1, latter λ ₁Be 0.6～0.70, λ ₂Be 1.0～1.1, Δ λ half-breadth 120A adopts the PIN detector.

2. controller according to claim 1, it is characterized in that described transducing head is made up of object lens (contactless distance is 1～12 meter), optical gate, standard school zero light source, GRIN Lens, beam splitter, graticule and eyepiece, head adopts the optical cable transmission, without any with the related electronic devices and components of signal.

3. controller according to claim 1 is characterized in that described closely camera lens, fibre-optical probe, biography resemble bundle, water sleeve wind cover protective device is auxiliary or replacement equipment of the present invention, so that enlarge usable range and increase other functions.

4. controller according to claim 1 is characterized in that λ ₁And λ ₂Be two train waves that obtain by interference filter, utilize the window of optical fiber, played λ ₁And λ ₂The effect that ends of two ends wavelength.

5. controller according to claim 2 is characterized in that the fibre-optical bending of standard school zero light source or the error that splicing loss brings, as long as press school zero button, error will show and eliminate.

6. controller according to claim 2, it is characterized in that telescopic system of said object lens and GRIN Lens composition, shortened light path, limited the λ that advances of marginal ray, prevented thermal source to measure width simultaneously, guarantee that this width is the sensor that depends on visible light beam splitter and double detector composition, guaranteed under the constant situation in tested interval that tested distance changes temperature and remains unchanged.

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