Impact hammer modal testing is an important step of the vibration testing and analysis phase in the manufacturing industry. Therefore, select an impact hammer after considering all the relevant parameters, such as analysis criteria and variations in testing setup. An impact hammer system is very specialized and very few companies manufacture them.

You can use a manual or remote operated impact hammer. A manually operated impact hammer resembles an actual hand-held hammer that strikes the sample. Remote operated impact hammers or electric impact hammers are automatic power tools controlled by a user. In traditional analysis systems, you have to record and compare test results manually. However, modern computerized systems provide a facility to record, compare and analyze the test results automatically.

Some of the important parameters you must consider before buying an impact hammer are:

1. Minimum and maximum force acting through the tip of impact hammer
2. Minimum and maximum pulse duration
3. The upper limit of the frequency range

Action Steps
The best contacts and resources to help you get it done

Buy an impact hammer from impact hammer suppliers

Once you understand your requirements, you can buy an impact hammer suitable for your testing setup. Check standard hammers sold by different manufacturers of impact hammers.

I recommend: Endevco Corp. offers a variety of electronic impact hammers. Dytran Corp. offers high frequency electric impact hammers. Refer to GlobalSpec, which provides a list of distributors of impact hammers.

Select sophisticated computer aided impact hammer systems from reputable companies

If you want to make a detailed impact modal analysis, use sophisticated computerized systems. These systems include an impact hammer system connected to a customizable software interface. The system can display, record, compare and analyze the test results.

I recommend: IOtech designs and manufactures data acquisition and measurement instrumentation used for modal analysis using impact hammers. LMS International also offers software enabled impact hammer systems useful for traditional modal analysis. Prosig also provides similar software integrated systems for impact hammer testing.

Calibrate your impact hammer system

As the impact hammer system is an important analysis tool, make sure you calibrate it by an expert team. Calibration is an important step of modal testing, and the smallest inaccuracy in test results can cause failure of complete modal analysis.

I recommend: You can implement ISO 9001 quality measures for your testing setup by consulting The Modal Shop, Inc. Lansbury International offers repairs and calibration of spring impact test hammers.

Tips & Tactics

Helpful advice for making the most of this Guide

• •  Consult an expert design engineer before buying an impact hammer testing setup.
• •  Keep an inventory of sensors for an impact hammer.