Portable alarm

A portable alarm configured to detect relative movement between a closure of an aperture and a wall forming the aperture, wherein the aperture and the wall form a monitored boundary such that relative movement between the closure of the aperture and the wall at the monitored boundary operate to facilitate opening and closing of the aperture, the portable alarm comprising:

• a detection body including a detection body mount configured to releasably mount the detection body to either the closure or the wall;
• a detector body, the detector body having a front side and a back side opposite the front side, the detector body including:
• a detector body mount at the back side of the detector body configured to releasably mount the back side of the detector body to either the closure or the wall;
• a first sensor carried by the detector body, the first sensor being configured to generate a sensor signal indicating relative movement between the detector body and the detection body;
• a transducer configured to controllably generate sound;
• a light source configured to controllably emit light;
• control electronics coupled with the first sensor, the control electronics being configured to control the transducer and/or the light source to generate a first feedback indicating close proximity between the first sensor and a second sensor carried by the detection body, and to control the transducer and/or the light source to generate a second feedback different from the first feedback, subsequent to provision of the first feedback, responsive to a reduction in proximity between the first sensor and the second sensor such that, responsive to the detector body and the detection body being mounted in proximity to each other on opposite sides of the monitored boundary, generation of the second feedback is indicative of relative movement of the closure to open the aperture.