Smiths Detection-watford Limited

Graseby Dynamics Limited

Smiths Group Plc

Other

Stephen John Taylor

Jonathan R Atkinson

Alastair Clark

Robert Brian Turner

William Angus Munro

John Fitzgerald

Paul Grant Wynn

Matt Easton

Bruce Grant

Paul Douglas Arnold

Matthew Easton

Robert Fagan Bradshaw

Henry McIntyre

Richard Turner, Legal Representative

Johnathan Richard Atkinson

Robert Fagan Donat Bradshaw

John Patrick Fitzgerald

Jonathan Richard Atkinson

Henry Mcintyre

Synchronized ion modification systems and techniques are described. An ion modifier can be used to modify a portion of ions that enter a drift chamber via a gate that controls entry of the ions to the drift chamber. A controller that is communicatively coupled to the ion modifier is configured to control the ion modifier to select a portion of the ion to be modified. In embodiments, the controller selects the portion based on a detector's previous response to other ions that are formed from a sample from which the ions were formed. The other ions, for example, correspond to ions that are associated with a peak in previous operation of a spectrometer.

Synchronized ion modification

Ion modification An ion mobility spectrometer () comprising a sample inlet () comprising an aperture arranged to allow a sample of gaseous fluid to flow from an ambient pressure region to a low pressure region of the ion mobility spectrometer to be ionised; a controller () arranged to control gas pressure in the low pressure region to be lower than ambient pressure; and an ion modifier () configured to modify ions in the low pressure region, wherein the ions are obtained from the sample of gas.

Sample probe inlet flow system

An ionising apparatus for ionising a sample of gaseous fluid. The ionising apparatus comprises an ioniser configured to provide reactant ions; an ion modifier configured to modify the reactant ions, and a reaction region arranged to receive the modified reactant ions and a sample and to combine the sample with the modified reactant ions to ionise the sample for analysis by a detector configured to identify a substance of interest in the sample.

Method and apparatus for the chemical ionization of samples

An apparatus includes a sample receiving port and an inlet assembly configured to be positioned adjacent to the sample receiving port. The inlet assembly defines a volume for receiving a sample and includes a gap that defines an extraction port. The extraction port is configured to extract one fluid flow to facilitate another fluid flow toward the sample receiving port. The extraction port can be configured as an annular flow port around the sample receiving port. In some instances, the apparatus also includes a curtain port positioned apart from the sample receiving port and the extraction port. The curtain port can be used to guide fluid away from interior surfaces of the inlet assembly and toward the sample receiving port, and/or to provide an environment of controlled air, and/or to isolate the sample receiving port from external sources of contamination.

Synchronized ion modification systems and techniques are described. An ion modifier can be used to modify a portion of ions that enter a drift chamber via a gate that controls entry of the ions to the drill chamber. A controller that is communicatively coupled to the ion modifier is configured to control the ion modifier to select a portion of the ion to be modified. In embodiments, the controller selects the portion based on a detector's previous response to other ions that are formed from a sample from which the ions were formed. The other ions, for example, correspond to ions that are associated with a peak in previous operation of a spectrometer.

An ionizing apparatus for ionizing a sample of gaseous fluid. The ionizing apparatus comprises an ionizer configured to provide reactant ions; an ion modifier configured to modify the reactant ions, and a reaction region arranged to receive the modified reactant ions and a sample and to combine the sample with the modified reactant ions to ionize the sample for analysis by a detector configured to identify a substance of interest in the sample.

A detecting method using an IMS apparatus with a preconcentrator outside its inlet aperture. Analyte vapor is adsorbed during a first phase when substantially no gas is admitted to the reaction region. The preconcentrator is then energized to desorb the analyte molecules and create a volume of desorbed molecules outside the IMS housing. Next, a pressure pulser is energized momentarily to drop pressure in the housing and draw in a small sip of the analyte molecules from the desorbed volume through the aperture. This is repeated until the concentration of analyte molecules in the desorbed volume is too low for accurate analysis, following which the apparatus enters another adsorption phase.

Pulsed admission of analyte to detection apparatus

IMS apparatus has an inlet with a preconcentrator opening into a reaction region where analyte molecules are ionized and passed via a shutter to a drift region for collection and analysis. A pump and filter arrangement supplies a flushing flow of clean gas to the housing in opposition to ion flow. A pressure pulser connects with the housing and is momentarily switched to cause a short drop in pressure, in the housing to draw in a bolus of analyte sample from the preconcentrator. Just prior to admitting a bolus of sample, the pump is turned off so that the flushing flow drops substantially to zero, thereby prolonging the time the analyte molecules spend in the reaction region.

Ion mobility spectrometer which controls carrier gas flow to improve detection

Systems and techniques for cleaning a corona discharge point are described. A controller () can be operatively coupled to a corona discharge point () to control the operation of the corona discharge point (. The controller () and the corona discharge point () can be included with, for example, an ion mobility spectrometry (IMS) system (). The controller () can be used to operate the corona discharge point () at an operating voltage for a first time interval, with or without an additional higher pulse voltage, to produce a corona discharge, and to operate the corona discharge point () at a cleaning voltage greater than the operating voltage for a second time interval subsequent to the first time interval to produce a corona discharge. The effectiveness of the corona discharge point () can be monitored by, for instance, measuring a voltage necessary to produce a corona discharge at the corona discharge point (), measuring a current produced at the corona discharge point () from a corona discharge, and so forth.

Cleaning of corona discharge ion source

An ion mobility spectrometer has a pair of electrodes and midway along the drill chamber. A high field is applied between the electrodes and sufficient to modify ions in the region of the electrodes such that they move at a different rate towards the collector plate. This is used to modify the time of flight of selected ions or ion clusters and enable identification of ambiguous peaks on the IMS spectrum.

Detection apparatus

An IMS or other analytical instrument has a corona discharge needle () to ionize sample gases or vapours. A gate () is opened or closed to admit or prevent entry of the ions produced by the corona discharge to a drift chamber (). The operation of the corona discharge needle () and the gate () are controlled such that the gate is open during at least two discharges, to admit faster ions produced by the most recent discharge together with slower ions produced by an earlier discharge.

Analytical apparatus

An IMS system or the like has dopant contained in a way such that it is only released when needed. The dopant could be contained in a device () similar to an ink-jet printer and released as droplets () when required. Alternatively, the dopant could be trapped in material () of a molecular sieve () in such a way that it is not normally released into air flowing through the sieve but can be released by energizing a heater () in the sieve.

Detection systems

A vapor generator system () for an IMS () or other apparatus has a chamber () in which vapor is produced. A fan or other flow generator () is connected to an inlet () of the vapor chamber () and its outlet () is connected to an adsorbent passage (), such as formed by a bore through a block () of carbon. When the fan () is on gas flows through the vapor chamber () and the adsorbent passage () to the IMS () or other outlet, with little vapor being adsorbed in the passage. When the fan () is off, any vapor molecules that escape to the adsorbent passage () do so at a low rate such that substantially all is adsorbed and no vapor escapes.

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Hyde Heath, United Kingdom

Stephen John Taylor