an adjustable probe holder assembly is disclosed for an inspection or measurement sensor , such as an ultrasound transducer , eddy current sensor , magnetic thickness sensor or optical image sensor , in order to position the sensor in a confined space using an extended arm with an adjustable curvature . the probe holder has at least two elongated holding arms , among which a first arm and a second arm , each having a probe end and a holding end , wherein the probe end of each of the holding arms are attached to the probe and the at least two arms remain substantially parallel and very close to each other when the probe holder is at a non - operational status . the two arms bulge open away from each other due to either a tension force or a compression force being exerted along the longitudinal direction of either one of the arms , holding the probe to be against the test surface of the test object .