Abstract: An apparatus for and a method of Nuclear Quadrupole Resonance testing a sample in the presence of interference are disclosed. The apparatus comprises excitation applying means for applying excitation, a first antenna for detecting a response to the excitation together with the interference, and a second antenna for detecting the interference, the first and second antennas being arranged such that a signal commonly detected in the two antennas is attenuated relative to a signal that is detected by only one of the antennas. The apparatus may provide suppression of interference.

Abstract: A method of and apparatus for analysing a signal is disclosed, the method comprising producing a model of the signal and comparing the model to a predetermined model of a signal due to a phenomenon, thereby to determine whether the model represents a signal due to that phenomenon. A method of and apparatus for detecting the presence of a sample in a larger sample which is not known to contain the sample is also disclosed, the method comprising detecting a signal comprising a response from the sample, producing a model of the signal, and comparing the model to a predetermined model of a response from the sample, thereby to determine whether the sample is present. The techniques have particular application in Magnetic Resonance and Quadrupole Resonance.

Abstract: A pump has meshing inner and outer rotors mounted eccentrically in a housing. The pump also has an inlet and a main outlet. The main outlet communicates via a control gap with a secondary outlet. The control gap provides a filtering action for some of the fluid pumped.

Abstract: A method of Nuclear Quadrupole Resonance testing a sample containing a given species of quadrupolar nucleus, the sample being subjected to an inhomogeneous distribution of an extrinsic parameter having a variation over the sample over a particular range, comprises applying excitation to the sample at a plurality of different excitation frequencies to excite nuclear quadrupole resonance, such frequencies falling within the resonance frequency range for the nucleus corresponding to the range of the extrinsic parameter, and detecting the resonance response signal.

Abstract: Apparatus for Nuclear Quadrupole Resonance testing a remote sample containing a given species of quadrupolar nucleus includes at least one probe (112) having a given maximum cross-sectional dimension; a device (102) for applying excitation to the probe or at least one of the probes to excite nuclear quadruple resonance for a selected range of distance of the sample from each such probe, the selected range being at least one tenth of the given maximum dimension of the probe, the apparatus being adapted to produce a non-uniform field over the selected range; and a device (106) for detecting the resonance response signal from the sample via the probe or at least one of the probes; the excitation being such as would generate non-zero resonance signals at all distances within the selected range.

Abstract: A method of Nuclear Quadrupole Resonance testing a sample containing a given species of quadrupolar nucleus, the sample being subjected to an inhomogeneous distribution of an extrinsic parameter having a variation over the sample over a particular range, comprises applying excitation to the sample at a plurality of different excitation frequencies to excite nuclear quadrupole resonance, such frequencies falling within the resonance frequency range for the nucleus corresponding to the range of the extrinsic parameter, and detecting the resonance response signal.