**Impact test** is to measure the ability of materials to resist high-rate impact. Impact resistance can be obtained by calculating the amount of energy that causes test specimen failure. In general, there are two kinds of testers for impact resistance: free-falling dart impact tester and pendulum impact tester,conforming to different international standards.

**BMC-B1 Packaging Drop Dart Impact Tester ISO 7765** is designed to measure impact resistance property of plastic films, paper and other packaging materials using free falling dart method.

### Principle

Before starting the test, choose test method, and estimate an initial mass and ÃŽâ€m. Start the test. If the first specimen fails, decrease the mass of the falling dart by ÃŽâ€m. If the first specimen is not a failure, increase the mass of the falling dart by ÃŽâ€m. Continue the test according to this rule. In brief, increase or decrease by ÃŽâ€m according to whether the former specimen is a failure or not. After 20 specimens, calculate the total number of failed specimens N. If N equals to 10, the test is over. If N is less than 10, add specimens and continue to test until N equals to 10. If N is greater than 10, add specimen and continue the test until the number of non-failure specimens reaches 10. Then the tester calculates the test results automatically according to specific formulas.