公开(公告)号：GB2302220A

公开(公告)日：1997-01-08

申请号：GB9618939

申请日：1995-03-20

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK

IPC: G01N27/64 ,  G01N27/66 ,  H05B41/16 ,  H05B41/24 ,  H05B41/38 ,  H05B41/19

Abstract: An ultra-violet lamp (19) has a pair of electrodes (31, 32) within the lamp, the electrodes being connected to a DC power supply (34). There is a coil (37) wound round the lamp, the coil being connected to an RF power supply (38). The DC power supply (34) and the RF power supply (38) are controlled by control means (39) adapted to activate an RF voltage in the coil (37) to initiate the supply of ultra-violet light (20) from the lamp, to activate a DC voltage between the electrodes (31, 32), and to switch off the RF voltage when the DC voltage is sufficient to maintain the supply of ultra-violet light.

公开(公告)号：AU1900695A

公开(公告)日：1995-10-09

申请号：AU1900695

申请日：1995-03-20

Applicant: SECR DEFENCE BRIT

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK

IPC: G01N27/64 ,  G01N27/66 ,  H05B41/16 ,  H05B41/24 ,  H05B41/38 ,  H05B41/18 ,  H05B41/232

公开(公告)号：GB2302220B

公开(公告)日：1998-04-29

申请号：GB9618939

申请日：1995-03-20

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK

IPC: G01N27/64 ,  G01N27/66 ,  H05B41/16 ,  H05B41/24 ,  H05B41/38 ,  H05B41/19

公开(公告)号：GB2288230A

公开(公告)日：1995-10-11

申请号：GB9509217

申请日：1993-11-12

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK

IPC: G01J1/42 ,  G01J1/54 ,  G01N21/33 ,  G01N27/64

Abstract: A device (19), for measuring changes in the intensity of a beam (52) of ultra-violet light, includes a gas tight container (10) having a window (11) translucent to ultra-violet light and containing detector means (12a, 20) sensitive to changes in the amount of ultra-violet light entering the container. The detector means (12a) might be a gas, ionisable by ultra-violet light, which fills the container (10), or a plate (20) having photo-electric sensitivity to ultra-violet light. The device includes means (13, 14, 15, 17. 17; 25, 26, 27, 28) for measuring the ultra-violet light. The device can be used as a gas detector, measuring the loss in ultra-violet light in a beam (52) from a lamp (51) crossing a passage (50) through which flows an airflow containing a contaminant gas of the type which absorbs or is ionised by ultra-violet light.

公开(公告)号：GB2283570A

公开(公告)日：1995-05-10

申请号：GB9425690

申请日：1994-12-20

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK ,  ROBERTS IAN DAVID

IPC: G01N33/00

Abstract: A vapour concentration calibration system includes means for supplying to a device (64) to be calibrated a first metered supply of air (primary air) (50) with which has been mixed a second metered supply of air (secondary air) (63) which has been saturated with a vapour, for example by pumping air through an air flowmeter (53) and thence, in the from of fine bubbles, through the liquid (56) whose vapour content is to be calibrated.

公开(公告)号：GB2239740A

公开(公告)日：1991-07-10

申请号：GB9101398

申请日：1991-01-18

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  ELIAS JOHN EVAN ,  TAYLOR DAVID MARTIN

IPC: H01T23/00

Abstract: A unipolar ion generator for use in atmospheric dispersion studies which may be pre-set to give a desired output current, such output current being steady and controllable, any fluctuations in the current being corrected by use of a control circuit. The output current is unaffected by adverse weather conditions and surface electrode conditions.

公开(公告)号：GB2343003A

公开(公告)日：2000-04-26

申请号：GB0001867

申请日：1998-08-05

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID

IPC: G01N27/66 ,  G01N33/00

Abstract: A gas detection device for distinguishing at a single point, two simultaneously emitted gases and, and in particular, for measuring the individual concentration of each gas at the point, comprising two flow passages into which a sample comprising the two gases is input, gas induction means for drawing the sample into and through the flow passages and means for irradiating each of the flow passages with ultraviolet radiation of a different energy. The device may comprise two sources of ultraviolet radiation, wherein each of the sources (e.g. a krypton and an argon lamp) emits radiation into one of the flow passages. Upon irradiation of the gases (e.g. propane and propylene) within the sample the gases are ionised, one of them being ionised by radiation in one of the flow passages and the other being ionised by radiation in both of the flow passages. Each flow passage has an associated bias electrode, and a collector electrode which are arranged downstream of the irradiated flow passages. The currents at the collector electrodes give an indication of the ionised gas (or gases) in each flow passage. The invention also relates to a method of measuring, at a single point, the individual concentrations of two simultaneously emitted gases. This measurement may be used in the development of models and other tools for determining, for example, gas hazard or nuisance. The device and method have particular application in environmental pollution monitoring. atmospheric tracer gas detection and in the monitoring of gas or vapour emitting processes.

公开(公告)号：GB2272297B

公开(公告)日：1995-05-17

申请号：GB9400181

申请日：1992-07-17

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID

IPC: G01N27/66 ,  G01N33/00 ,  G01N27/64 ,  H01J41/02

Abstract: An improved ionisable gas or vapour detector device and method are provided which are capable in preferred forms of sampling 4 x 10 cubic metres or more of air sec and are responsive to ionisable gas fluctuations at a rate of up to 100Hz. Use of the device of the present invention has proved to provide sensitivity to UV ionisable gas or vapour of over 500 times that of prior devices, giving detection of propylene tracer gas at concentrations of 2 parts per 1,000,000,000 and thus increasing the range from the gas source at which the device may be reliably used. Use for detection of leaks of volatile UV ionisable compounds and for monitoring processes where vapours are emitted is also provided.

公开(公告)号：AU6507694A

公开(公告)日：1994-11-21

申请号：AU6507694

申请日：1994-04-13

Applicant: SECR DEFENCE BRIT

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK ,  ROBERTS IAN DAVID

IPC: G01N33/00

公开(公告)号：GB2273779A

公开(公告)日：1994-06-29

申请号：GB9226663

申请日：1992-12-22

Applicant: SECR DEFENCE

Inventor： JONES CHRISTOPHER DAVID ,  GRIFFITHS RICHARD FREDERICK

IPC: G01N27/66

Abstract: A gas detector includes a conduit 10 defining a gas flow passage 11 having an inlet 12 and an outlet 13, an ultraviolet light source 14 mounted to direct a beam of ultraviolet light 15 through the gas flow at right angles to the flow direction to ionise a teat gas in the gas flow, the conduit 10 having a substantially right angled bend 16 immediately after the light source 14 and having a pair of electrodes 17, 18 positioned immediately after the bend 16 for measuring ionisation current. The conduit may be of rectangular, preferably square, section with flat plate electrodes 17, 18 or of tubular, preferably circular, section with electrodes 19, 20 of concentric annular form. The detector may be used to detect tracer gases in an air flow.