Calipers combine extremely accurate measurements with easy hand-held use and are an essential tool in the workshops and toolboxes of many home remodeling enthusiasts. Three types of calipers exist -- vernier, dial and digital. Digital calipers display measurement readings in an easy-to-read electronic format, and their lack of gears or teeth give them a better chance to avoid error-causing contamination issues. The L.S. Starrett company's No. 722 digital caliper is an older model with a reputation for heavy battery usage.
Press down on the button with the "Starrett" logo and remove the caliper's electronics casing. Place the casing cover to the side.
Remove the two dead batteries from the caliper.
Place the two new 386 model 1.5v batteries in the caliper. The "stepped" side of the battery, with the smaller face, should face upwards. Ensure the batteries are sitting flush in their connection.
Replace the caliper's casing. The casing should snap back into place.