Analog 9572281 Compression Tester

Testers are typically used a bank at a time or as an engine set. Once installed on the engine the operator must prevent the engine from starting. The batteries are used to crank the engine to trap readings. If a power assembly is identified as being low a second test should be performed with a reliable tester (new preferable) to duplicate the reading, and if the readings are consistent the power assembly should be removed.