Patent ID: 8694091

Claim:
A bolus for introducing into a ruminant animal's (A) reticulum (R) and for ongoing measurement of an acidity level of an animal's stomach fluids, the bolus ( 100 ) comprising: a housing ( 100 ) having an outermost surface exterior wall; a cavity defined by a portion of the exterior wall of the housing, the cavity (C 1 , C 2 ) having a wall of dielectric material and at least a first opening for receiving ruminal fluids into the cavity, the wall defining a dielectric conduit ( 110 ), the first opening being an unobstructed opening freely allowing the ruminal fluids from the animal's (A) reticulum (R) to be received into the cavity; a power generator ( 310 ) that generates electric power within a spectral range; a sensor coil ( 120 ) encircling the dielectric conduit ( 110 ) and powered by the power generator, the sensor coil ( 120 ) configured to subject the received ruminal fluids (L) within the cavity to an electromagnetic field (B) within the spectral range; a processor ( 320 ) connected to the sensor coil ( 120 ) to measure, under influence of the electromagnetic field (B), an electromagnetic property (z) of the ruminal fluids (L), wherein from the measure of the electromagnetic property (z), the processor ( 320 ) determines an acidity measure (M pH ) of an acidity level of the ruminal fluids (L); and a transmitter ( 410 ) connected to the processor ( 32 ) and configured to transmit a wireless output signal (S D ) reflecting the determined acidity measure (M pH ), wherein the power generator ( 310 ), the sensor coil ( 120 ), the processor ( 320 ), and the transmitter ( 410 ) are each located within the housing ( 100 ).