142 results about "Pyroelectric detectors" patented technology

The present invention provides a method and apparatus for estimating a property of a fluid downhole by exposing the fluid to modulated light downhole and sensing changes in intensity of infrared radiation from the downhole fluid to estimate the property of the downhole fluid. The present invention senses changes in intensity of light by converting the changes to transient changes in temperature of a detector, such as a pyroelectric detector. The present invention performs spectroscopic analysis of fluids by optically filtering the light allowed to impinge on a pyroelectric detector, converting the changes in temperature of the pyroelectric detector to a signal and converting the signal to estimate the property of the downhole fluid. The light source is modulated by mechanically chopping the beam or by electrically pulsing the light source or by steering the beam between different path lengths of sample or between a reference cell (filled with a reference fluid or empty) and a sample-filled cell.

One embodiment of the present invention is a system for identifying a human being from movement of the human being. The system includes a dual element pyroelectric detector, a Fresnel lens array, and a processor. The dual element pyroelectric detector detects radiation from the human being as the human being moves over time. The Fresnel lens array is located between the dual element pyroelectric detector and the human being. The Fresnel lens array improves collection efficiency and spatial resolution of the dual element pyroelectric detector. The Fresnel lens array includes a mask. The mask provides at least one zone of visibility. The processor is coupled to the dual element pyroelectric detector, the processor converts the detected radiation to a spectral radiation signature. The processor compares the spectral radiation signature to at least a second spectral radiation signature to identify the human being.

The invention relates to a visual detection method of longitudinal tear of a conveying belt, which belongs to the technical field of on-line monitoring of coal mine automation. The visual detection method is characterized in that in the condition of dim light or no light, a pyroelectric detector is used for detecting the temperature variation of the conveying belt due to the longitudinal tear, an infrared CCD (Charge-coupled Device) camera is controlled to take a photo, an obtained image is processed, and then an accident of the conveying belt can be accurately judged. According to the visual detection method, the simultaneous working mode of timing photo taking and triggering photo taking is adopted, omitted judgment caused by failure of the pyroelectric detector is prevented, and great energy of the infrared CCD camera, which is consumed by continuously taking photos for a long time, is saved. Additionally, negative effects that the service life of the infrared CCD camera is shortened and the working efficiency is reduced are avoided, wherein the negative effects are caused by the fact that the infrared CCD camera is continuously operated for a long time. A sharp image can be obtained by the infrared CCD camera when the conveying belt is moved at high speed, the obtained image is a grayscale image and is easily processed at a later period, and the position and the degree of the longitudinal tear can be visually reflected through finally processed information. The visual detection method has the advantages of high precision and reliable performance.

The present invention provides systems and methods for quantifying, purifying and separating fullerenes, such as single wall carbon nanotubes (SWNTs). The purification/separation combination provides nearly 100% carbonaceous impurity-free SWNT content from a given impure sample and provides a desired chirality and diameter from a given non-separated sample. Nanometrological validation of the success of purification and separation uses a pyroelectric detector and Raman spectroscopy in a single system, thus providing a critical aspect for the nanomanufacturing environment. The purification/separation and nanometrological validations may be performed in a feedback loop to provide a satisfactorily refined sample and optimized purification/separation settings.

An infrared detector (301) is provided which comprises a pyroelectric detector (303) having first and second sensing elements (345), an aperture stop (311), and a Fresnel lens array (305). The detector may be used as a passive infrared sensor unit for detecting intrusion into large openings.

The invention discloses an anti-ferroelectric membrane with adjustable working temperature area and large heat-releasing rate, and the method for preparing the same and its application. It applies sol-gel method to prepare said anti-Ferroelectric membrane ((Pb, La or Nb) (Zr, Sn, Ti) O3, the solute of precursor comprises acetate lead, the acetate lanthanum or ethanol nb, acetate tin, zirconium iso-propoxide and titanium iso-propoxide; the solvent comprises acetic acid, glycol ethylene ether and water; the final concentration of precursor is controlled between 0.2-0.4 M. the bed piece is LaNiO3/Pt/Ti/SiO2/Si and Pt/Ti/SiO2/Si. The product is mainly used for infrared heat-releasing electrical detector, smart device and system.

Graphene and ferroelectric materials are used as tunable sensors for detecting and measuring radiation, such as infrared radiation. The low absorption and reflectance of graphene and interconnected graphene networks, for example in the infrared, are exploited for use in such tunable sensors. The active layer makes use of a unique property of ferroelectric materials, known as the pyroelectric effect, for measuring the intensity of impinging radiation. Using graphene electrodes may offer a significant increase in sensitivity, tunability and mechanical flexibility of sensors, such as infrared sensors. In one method, intensity of radiation is measured using variations in the doping level of the graphene electrode.

Using biased, electrical power feedback to an electrical heater, the output signal from a pyroelectric detector is made to follow the waveform of incident electromagnetic radiation. The feedback power is applied to the detector to reduce the rate of change of the detector temperature that would otherwise be caused by the absorbed radiation. The combined signals from the radiation and feedback power produce a response that follows the radiation waveform with a fast rise time and with substantially less droop than previously reported. The high fidelity of the response waveform allows for a substantial simplification of the optical chopper designs and electronics needed to implement electrical calibration. In contrast to previous electrical calibration with pyroelectrics that needed very specialized electronics, with this method a variety instruments can be used for reading pyroelectric signals. The method allows for signal processing that reduces phase noise and yields very accurate radiation power measurements.

The invention discloses La2O3-doped lead zirconate titanate antiferroelectric ceramic. The components and the molar ratio of the components of the ceramic are represented by a formula of Pb1-xLax(Zr0.70Ti0.30)1-x/4O3, wherein x=0.07-0.18. According to the invention, a traditional oxide mixing method is adopted, and sintering is carried out under a normal pressure, such that the antiferroelectric ceramic material is obtained. With the antiferroelectric ceramic provided by the invention, a double hysteresis loop can be displayed under room temperature, the loss is low, and the temperature coefficient is relatively small. The antiferroelectric ceramic is mainly applied in high-density energy-storage capacitors, large-displacement actuators, energy transducers, controllable switches, pyroelectric detectors, and the like.

The invention discloses an infrared multiparameter fire and gas detector which comprises a shell and an optical window assembly, a detector element array, a fire alarm indicator light and a main control circuit board installed inside a cavity of the shell, wherein the detector element array is a composite fire detector; the optical window assembly comprises an optical lens and a fastening and locating assembly thereof, and the fastening and locating assembly is used for fastening and locating the optical lens in an elastic soft touch manner; and the detector element array at least comprises three pyroelectric detectors with center wavelengths of 3.8 mum, 4.3 mum and 5.0 mum respectively. A plurality of pyroelectric detectors with different bands are used for detecting flames and environment background signals, a signal collected by an intelligent infrared CO/CO2 gas detector is combined, a temperature signal detected by lead sulfide can also be used as an aid, the fusion of information from multiple sensors is realized, and the purposes of alarming in advance and reducing false alarms are better reached. The fire and gas detector provided by the invention has compact structure, small size, high reliability and high sensitivity to early fire detection and is not influenced by sunlight and visible light, and the total design conforms to the explosion proof requirements in national standards.

The invention discloses a carbon monoxide (CO) concentration and visibility detector and a detection method. The CO concentration and visibility detector comprises an infrared thermal light source, a double-filtering-piece infrared pyroelectric detector, a reference light path measuring the light intensity of the light source under an ideal environment, a measurement light path measuring the light intensity of the light source under an actual environment, a turntable for switching the two light paths and a circuit board for data acquisition and processing. The CO concentration and visibility detector achieves simultaneous detection of CO concentration and visibility, only needs one set of light paths, a mechanical structure, a hardware circuit, the single light source and a unit-doublet detector, can eliminate scattered infrared light, dust on a camera lens and errors caused by absorption of system parts and is accurate in measurement. A dual-wavelength method is adopted to detect gas concentration, a high-concentration gas reference air chamber is omitted, and a system structure is simplified. The detector is small in size and convenient to use.

The invention discloses an infrared gas sensor based on BP (Back Propagation) neural network pressure compensation and a detection method. The infrared gas sensor based on the BP neural network pressure compensation comprises an infrared gas sensor, a pressure sensor and a micro processing system embedded with a BP neural network algorithm; the infrared gas sensor comprises a sampling gas chamber; the left end of the top of the sampling gas chamber is provided with a gas inlet; the right end of the top of the sampling gas chamber is provided with a gas outlet; the left end of the inside of the sampling gas chamber is provided with an electric modulation infrared light source; a light filtering wheel is arranged at the right end of the inside of the sampling gas chamber; a light filtering plate group is arranged in a middle position of the left side surface of the light filtering wheel; the light filtering plate group comprises two light filtering plates with different wave lengths; in addition, the two light filtering plates are symmetrical in the vertical direction; a binary heat release electric detector is arranged in a middle position of the right side surface of the light filtering wheel. The infrared gas sensor has the characteristics that the precision is high; the structure is simple; the applicability is high; the network training speed is high; the full compensation can be realized, and the like.

The invention relates to a multi-functional multi-channel pyroelectric infrared detector used for gas analysis and fire detection, comprising a detector shell, a filter inlaid on the top surface of the shell, a pyroelectric film arranged on the side wall of the shell, a support used for supporting the pyroelectric film, a detector base forming a closed space with the shell, a circuit board arranged on the base, a platinum wire connected with the pyroelectric film and the circuit board, a curved reflective mirror positioned on the circuit board and a pin inlaid under the circuit board. The multi-channel pyroelectric infrared detector has the advantages of scientific structural design, wide application range, standard packaging, stable performance, high detectivity and high integration degree.

The invention discloses an antiferroelectric film with adjustable working temperature zone and higher pyroelectric coefficient and a preparation method and application thereof. The antiferroelectric film (Pb,Nb)(Zr,Sn,Ti)O3 taken as the pyroelectric material is prepared by a sol gel method, the solute of precursor solution can be lead acetate, lanthanum acetate or niobium ethoxide, stannic acetate, zirconium isopropoxide and titanium isopropoxide, the solvent includes glacial acetic acid, ethylene glycol ethyl ether, acetylacetone and water, the final concentration of the precursor solution is controlled between 0.2-0.4 M, and the substrate comprises LaNiO3/Pt/Ti/SiO2/Si and Pt/Ti/SiO2/Si. The antiferroelectric film is high in thermally stimulated current and adjustable in temperature andcan be used for a pyroelectric infrared detector, a smart device and a system.

The invention discloses a terahertz wave band nanosecond time-resolved Fourier transform spectrometer, comprising a michelson interferometer, a sample room arranged at an input end of the michelson interferometer, a THz quantum well detector arranged at an output end of the michelson interferometer, a THz source, a modulating signal module, a phase-locked amplifier and a control computer. The phase-locked amplifier is connected with the THz quantum well detector; the control computer is connected with the phase-locked amplifier and is further connected with a movable mirror of the michelson interferometer to control the position of the movable mirror so as to move the fixed step length of the movable mirror; and the THz source and the modulating signal module emit a THz laser with a disturbing signal to the sample room, transmit the disturbing signal to the phase-locked amplifier, and transmit the disturbing signal which is amplified by the phase-locked amplifier to the control computer. The existing DTGS-PE and Si pyroelectric detector is replaced by the THz quantum well detector, so that the time resolution of the Fourier transform spectrometer within the THz wave band is greatly improved.

The invention relates to an NDIR gas sensor system. The NDIR gas sensor system comprises an infrared sensor unit, a microprocessor and a concentration display unit, wherein the microprocessor system is connected with the infrared sensor unit and the concentration display unit; a sampling air chamber can effectively prolong an optical path and can control the volume of the air chamber to facilitatethe miniaturization of the sensor. The potassium bromide (KBr) window piece is arranged to avoid corrosion of a pyroelectric detector, the service life of the sensor is prolonged, and the optical paths of the measuring channel and the reference channel are completely symmetrical, so that the structural design of the single light source dual-optical path can eliminate the influence of external factors such as light source shake, optical device pollution and the like on the measuring precision to a certain extent. The NDIR gas sensor system and the temperature and humidity compensation method thereof employ a GSO-BP neural network to perform temperature and humidity compensation to overcome the defects of the empirical formula compensation method and the circuit compensation method in the prior art and lead the compensation process to be simpler and more accurate, and therefore, the precision is high, the cost is low and the structure is small compared to the prior art.

The invention relates to a reading circuit based on relaxor ferroelectric monocrystal pyroelectricity, which can realize the outputting of a relaxor ferroelectric monocrystal pyroelectric signal. The output current signal of the relaxor ferroelectric detector is converted into a voltage signal through an CTIA input-stage circuit module, the voltage signal is output after amplification, a double sampling hold circuit samples the signal twice, and a multichannel transmission circuit outputs the signals in each channel after conduction. The circuit modules are integrated on an integrated circuit chip and connected with a detector chip, and the control signal of the circuit modules is provided by an external drive circuit, thus the integrated circuit chip can effectively read the signal of the relaxor ferroelectric detector.

A micro-motion occupancy sensor system monitors for a presence of a person in a room, in different monitoring modes, to regulate power delivery to the room. The micro-motion occupancy sensor has a multimode lens for receiving passive infrared (IR) energy and focusing the IR energy as a series of IR beams, a pyroelectric detector to receive the focused IR beams and generate an electrical signal, a processing circuit to amplify, filter and processes the electrical signal to generate an interrupt signal and an analog output signal and a controller that receives and processes the interrupt signal and the analog output signal to determine whether a person has entered a room or is maintaining their presence within the room. The controller controls the processing in a vacant mode where a person's presence is not detected and in an occupied mode when a person's presence has been detected.

The invention discloses a two-stage reading circuit based on a relaxation ferroelectric monocrystalline pyroelectric detector, and the reading circuit comprises a first-stage CTIA (capacitor feedback mutual conductance) input stage circuit, a switching capacitor low-pass filter, a second CTIA amplification circuit, and a sampling output circuit. The first-stage CTIA input stage circuit enables an output current signal of the relaxation ferroelectric detector to be converted into a voltage signal, and the switching capacitor low-pass filter inhibits external noises. The second CTIA amplification circuit enables the signal to be amplified, and the sampling output circuit carries out signal sampling. All channels are conducted for sequential output. A circuit module is integrated on an integrated circuit chip, and is connected with a detector chip. An external drive circuit is used for providing a control signal, and the bandwidth of the low-pass filter is controlled through the adjustment of external clock frequency. The second CTIA amplification circuit achieves the further amplification of the signal, and improves the signal to noise ratio of the signal, thereby providing a large-scale multi-element small-area sensitive pyroelectric focal plane. The circuit provided by the invention is linear in output, is high in signal to noise ratio, and is an integrated weak signal reading circuit.

The invention discloses a high-sensitivity multi-gas concentration detection system with a constant-temperature control function, and a control method, and belongs to the technical field of gas sensors. A gas chamber of the detection system adopts a reflection structure; infrared light is reflected on a cavity wall for multiple times on the basis that the gas chamber is designed to be sufficientlysmall, and then the infrared light is transmitted to a pyroelectric detector; the concentrations of different gases are determined by analyzing the change of the infrared light intensity at a specific wavelength; and finally concentration information is displayed on a mobile phone terminal in a wireless transmission mode through a WIFI module. In addition, the gas chamber is formed by the opticalcavity wall with a graphene heating sheet, and the environment temperature of the detection system is controlled to ensure the constant temperature in the gas chamber of a gas sensor, so that the influence of environment temperature change on a detection result is eliminated.

The invention belongs to the technical field of TeraHertz wave detection and discloses a scanning fabry-perot interferometer used for line width measurement at a TeraHertz wave band. According to the technical scheme, TeraHertz wave line width measurement device and method include that incidence TeraHertz wave is emitted to a fabry-perot interferometer endoscope in parallel after passing a first off-axis parabolic mirror plated with gold at the surface; a fabry-perot interferometer endoscope a and a fabry-perot interferometer endoscope b are fixed at positions made of high-resistance silicon material; a stepping mobile platform performs stepping movement along the TeraHertz wave propagation direction; the parallel incidence TeraHertz wave from the endoscope b is gathered through a second off-axis parabolic mirror plated with gold at the surface; the focal position of the second off-axis parabolic mirror plated with gold at the surface is provided with a chopper, the second off-axis parabolic mirror plated with gold at the surface outputs the TeraHertz wave, and the measurement result is output through the chopper, a pyroelectric detector and an AD converter. The TeraHertz wave line width measurement device and method are mainly used for the TeraHertz wave detection.