one of the feature being present an exemplary esophageal diagnostic sensor is shown in various views in fig1 4 the sensor has sensor or capsule body 10 having a size and shape suitable for use within the esophagus of a human a sensor system is carried by the sensor body 10 in the example presented the sensor system comprises three half ring impedance electrodes 12 separated from each other longitudinally and each being distributed circumferentially around the sensor body 10 the sensor system also in this example comprises a ph sensor 14 15 formed of a sensing electrode 14 and reference electrode 15 stainless steel half ring electrodes 12 may be utilized to measure impedance and discriminate between acidic and non acidic esophageal reflux ph sensor electrodes 14 15 may comprise a standard antimony electrode 14 linked via electronics to an internal reference electrode 15 the sensor system may also include any number of other sensors suitable for detecting a physiological parameter of the esophagus or any other part of the gastrointestinal tract of a human including video cameras and pressure sensors a processing and communication module 16 is connected to the sensor system 12 14 a magnet 18 is bound to the sensor body 10 by in this exemplary case being contained within the sensor body 10 and separated from the processing and communication module 16 by insulating spacer 19 the magnet 18 may for example be a neodymium iron boron magnet of suitable size and shape for example a 6 5 mm u00d7 26 mm u00d7 1 5 mm magnet included in the capsule to facilitate magnetic holding as.