Noise, Vibration and Harshness (NVH): EVA
The EVA is a hand-held electronic scan tool which will assist in locating the source of unacceptable vibrations. The vibration sensor can be remotely mounted anywhere in the vehicle for testing purposes. The unit displays the 3 most common vibration frequencies and their corresponding amplitudes simultaneously. A bar graph provides a visual reference of the relative signal strength (amplitude) of each vibration being displayed and its relative G-force. The keypad is arranged to make the EVA simple to program and use. Some of the functions include the ability to average readings as well as record, play back and freeze readings. The EVA has a strobe balancing function that can be used to detect imbalance on rotating components such as a driveshaft or engine accessories.
| Item | Description |
|---|---|
| 1 | EVA screen |
| 2 | Frequency mode displayed in rpm or Hz |
| 3 | Active sensor input (A or B) |
| 4 | Current active mode |
| 5 | G-force indicators or the strongest frequencies in descending strength of each vibration |
| 6 | Strength of each vibration |
| 7 | Frequency in rpm/Hz of each vibration |
Record the readings taken with the diagnostic tool.
- Frequencies should be read in the "average" mode.
- Frequencies have a range of plus or minus 2 Hz. A reading of 10 Hz can be displayed as an 8 Hz through 12 Hz.