The Class J Impact Testing System for Charpy and Izod is designed with a measuring accuracy range of 10% to 80%. This means that if you are using a 22J hammer, your accurate testing range will be from 2.2J to 22J. If you require accuracy down to 1J, it is suggested to include the 2.75J pendulum hammer in the solution. This ensures that your testing needs are covered across the entire Izod testing range, from 22J down to 1J.