Abstract: A radiation spectrometer includes a scintillator, a photomultiplier, and one or more light-emitting diodes (LEDs). The scintillator receives radiation from the environment and emits light that is indicative of an energy of the radiation. The photomultiplier receives the light and outputs an electrical signal that is in turn indicative of the energy of the radiation. Spectral data can be generated based upon the electrical signal, wherein the spectral data indicates a number of radiation events in each of several energy bins. The one or more LEDs can emit LED light through the scintillator and toward the photomultiplier, wherein the LED light causes an LED peak in the spectral data that can be used to identify an absolute energy of radiation events in the spectral data.

Abstract: The present application relates to pulsed discharge ionization detectors (PDIDs) and non-radioactive ionization sources, including miniaturized forms thereof. In some examples, the PDID includes annular electrodes, where each electrode is disposed between annular insulators. Also provided herein are methods of making and using such PDIDs, such as for detecting one or more volatile organic compounds, as well as non-radioactive ionization sources.

Abstract: The present application relates to pulsed discharge ionization detectors (PDIDs) and non-radioactive ionization sources, including miniaturized forms thereof. In some examples, the PDID includes annular electrodes, where each electrode is disposed between annular insulators. Also provided herein are methods of making and using such PDIDs, such as for detecting one or more volatile organic compounds, as well as non-radioactive ionization sources.

Abstract: The present application relates to pulsed discharge ionization detectors (PDIDs) and non-radioactive ionization sources, including miniaturized forms thereof. In some examples, the PDID includes annular electrodes, where each electrode is disposed between annular insulators. Also provided herein are methods of making and using such PDIDs, such as for detecting one or more volatile organic compounds, as well as non-radioactive ionization sources.

Abstract: The present invention relates to surface mount structures including a capacitive element or a resistive element, where the element has a property that is responsive to an environmental condition. In particular examples, the structure can be optionally coupled to a printed circuit board. Other apparatuses, surface mountable structures, and methods of use are described herein.

Abstract: A novel measurement technique is employed using surface acoustic wave (SAW) devices, passive RF, and radiation-sensitive films to provide a wireless passive radiation sensor that requires no batteries, outside wiring, or regular maintenance. The sensor is small (<1 cm2), physically robust, and will operate unattended for decades. In addition, the sensor can be insensitive to measurement position and read distance due to a novel self-referencing technique eliminating the need to measure absolute responses that are dependent on RF transmitter location and power.

Abstract: A method of multi-dimensional moment analysis for the characterization of signal peaks can be used to optimize the operation of an analytical system. With a two-dimensional Péclet analysis, the quality and signal fidelity of peaks in a two-dimensional experimental space can be analyzed and scored. This method is particularly useful in determining optimum operational parameters for an analytical system which requires the automated analysis of large numbers of analyte data peaks. For example, the method can be used to optimize analytical systems including an ion mobility spectrometer that uses a temperature stepped desorption technique for the detection of explosive mixtures.

Abstract: A wireless passive temperature sensor comprising a surface acoustic wave (SAW) delay line is constructed on a piezoelectric substrate having a thermal coefficient of frequency. An array of addressable, wireless passive temperature sensors can be used to monitor an array of temperature points on a structure using a wireless reader. Each sensor can be monitored by measuring the frequency of maximum reflection in their respective bands. A wireless passive heat flux gauge uses two temperature sensors with different frequency and/or time delay responses to measure that temperature differential across a thermal conductor that has a well characterized thermal conductivity and thickness.

Abstract: An ion mobility spectrometer does not require a physical aperture grid to prevent premature ion detector response. The last electrodes adjacent to the ion collector (typically the last four or five) have an electrode pitch that is less than the width of the ion swarm and each of the adjacent electrodes is connected to a source of free charge, thereby providing a virtual aperture grid at the end of the drift region that shields the ion collector from the mirror current of the approaching ion swarm. The virtual aperture grid is less complex in assembly and function and is less sensitive to vibrations than the physical aperture grid.

Abstract: A correlation spectrometer can detect a large number of gaseous compounds, or chemical species, with a species-specific mask wheel. In this mode, the spectrometer is optimized for the direct measurement of individual target compounds. Additionally, the spectrometer can measure the transmission spectrum from a given sample of gas. In this mode, infrared light is passed through a gas sample and the infrared transmission signature of the gasses present is recorded and measured using Hadamard encoding techniques. The spectrometer can detect the transmission or emission spectra in any system where multiple species are present in a generally known volume.

Abstract: Correlation ion mobility spectrometry (CIMS) uses gating modulation and correlation signal processing to improve IMS instrument performance. Closely spaced ion peaks can be resolved by adding discriminating codes to the gate and matched filtering for the received ion current signal, thereby improving sensitivity and resolution of an ion mobility spectrometer. CIMS can be used to improve the signal-to-noise ratio even for transient chemical samples. CIMS is especially advantageous for small geometry IMS drift tubes that can otherwise have poor resolution due to their small size.

Abstract: A method is described for producing tubular substrates having parallel spaced concentric rings of electrical conductors that can be used as the drift tube of an Ion Mobility Spectrometer (IMS). The invention comprises providing electrodes on the inside of a tube that are electrically connected to the outside of the tube through conductors that extend between adjacent plies of substrate that are combined to form the tube. Tubular substrates are formed from flexible polymeric printed wiring board materials, ceramic materials and material compositions of glass and ceramic, commonly known as Low Temperature Co-Fired Ceramic (LTCC). The adjacent plies are sealed together around the electrode.

Abstract: The acoustic-wave sensor. The acoustic-wave sensor is designed for ambient or vapor-phase monitoring of a photoresist-stripping agent such as N-methylpyrrolidinone (NMP), ethoxyethylpropionate (EEP) or the like. The acoustic-wave sensor comprises an acoustic-wave device such as a surface-acoustic-wave (SAW) device, a flexural-plate-wave (FPW) device, an acoustic-plate-mode (APM) device, or a thickness-shear-mode (TSM) device (also termed a quartz crystal microbalance or QCM) having a sensing region on a surface thereof. The sensing region includes a sensing film for sorbing a quantity of the photoresist-stripping agent, thereby altering or shifting a frequency of oscillation of an acoustic wave propagating through the sensing region for indicating an ambient concentration of the agent. According to preferred embodiments of the invention, the acoustic-wave device is a SAW device; and the sensing film comprises poly(vinylacetate), poly(N-vinylpyrrolidinone), or poly(vinylphenol).

Abstract: Moisture corrosive gas stream is measured as a function of the difference in resonant frequencies between two acoustic wave (AW) devices, each with a film which accepts at least one of the components of the gas stream. One AW is located in the gas stream while the other is located outside the gas stream but in the same thermal environment. In one embodiment, the film is a hydrophilic material such as SiO.sub.2. In another embodiment, the SiO.sub.2 is covered with another film which is impermeable to the corrosive gas, such that the AW device in the gas stream measures only the water vapor. In yet another embodiment, the film comprises polyethylene oxide which is hydrophobic and measures only the partial pressure of the corrosive gas. Other embodiments allow for compensation of drift in the system.

Abstract: A ferroelectric optical image comparator has a lead lanthanum zirconate titanate thin-film device which is constructed with a semi-transparent or transparent conductive first electrode on one side of the thin film, a conductive metal second electrode on the other side of the thin film, and the second electrode is in contact with a nonconducting substrate. A photoinduced current in the device represents the dot product between a stored image and an image projected onto the first electrode. One-dimensional autocorrelations are performed by measuring this current while displacing the projected image.