A vacuum insulating panel includes first and second substrates (e.g., glass substrates), a hermetic edge seal, a pump-out port, and spacers sandwiched between at least the two substrates. The gap between the substrates may be at a pressure less than atmospheric pressure to provide insulating properties. A sensor body (e.g., spinnable magnetic body, which may be substantially spherical in shape) is provided at least partially in a recess defined in at least one of the substrates, and is configured to be spun at a high rate of speed in order to measure a pressure of the recess and/or gap between the substrates.