Reuben Hale, P.E.
Ph: (510) 507-1300
Sensitivity testing involves making predictions of system response to environmental disturbance. The significance and importance of the system sensitivity estimates is very often overlooked. This gets companies in trouble and is one of the top reasons why we are called upon to provide timely solutions. Most teams are focused on getting their product to work and get it out the door. An engineering team will often not know how to quantify what to expect in the customer environment and how to test for those expected disturbances. We design hundreds of sensitivity tests and can explain the important concepts to consider in designing the tests and making the right measurements that allow for sound estimates of system response. This is an important expertise we use in our vibration, acoustic and magnetic field consulting services.
The frequency dependent sensitivity estimates must often be translated in to a specification for the customer. The vibration, acoustic, and magnetic field specification serves as an understanding between the manufacturer and the customer. If the tool has a performance problem and the site no longer meets the specification then the customer may take responsibility to analyze the issue and fix the facility problem. If the tool has a performance problem due to facility disturbance and yet the levels are within the specifications, then the tool manufacturer may be asked fix the tool, or take the tool back.
We have found that the worst scenario is when the specification is too lax and the disturbance becomes an intermittent problem. At this point the customer has gone through all the preparation work, installed the tool, and gone through training, only to find that the tool does not perform well and that the manufacturer is to blame because they really didn't know the sensitivity of their product. On the other hand, a specification that is too hard to meet may cause the customer to choose a competitor's product that has a less stringent specification.
Thus, we feel that the best approach is to create a realistic specification that will accommodate the widest variety of installation sites and yet still provide confidence that it can be used to reject the sites that really would result in poor tool performance and unhappy customers. To accomplish this, thorough testing must be done on multiple tools to insure that the sensitivity measured is representative of the actual population of manufactured tools, given system variations, critical sensitive structures and processes.
Sensitivity testing for the following is explained below:
- Floor vibration
- Acoustic noise
- Magnetic Field
- Sensitivity Testing Topics Include:
Overview, Floor Vibration Sensitivity, Acoustic Noise Sensitivity, Magnetic Field Sensitivity