An abnormal sound inspection is one of the inspections performed before an engine is delivered. As the abnormal sound, there are versatile causes such as unbalance of component parts, electrical noise or knocking phenomenon and so on. At present, inspections depending on human senses such as hearing check using stethoscopic probe by operator. But operating environment makes it difficult to judge the sound by using microphone even though it might be considered as one of the determination method. For that reason, the detection from vibration is gradually introduced. In this example, the VC-3200 enables not only detection of vibration by band pass filter and quantitative judgment by level judgment but also hearing check with headphones.
 

The VC-3200 can be setup three frequency bands and make Pass/Fail judgment based on the rms, peak on each band or power averaging calculated value (same for all bands). Also it has effective functions such as comparator delay time setup function and auto operation function. The comparator delay time setup function removes unwanted signal at the time of starting measurement and the automatic operation function can control the timing of judgment by inputting a control signal from external device such as PLC*. Although the VC-3200 can be operated by 24VDC (22 to 26VDC) as standard, you have an alternative to use it at 100 VAC by connecting the optional AC/DC convertor VC-0352.
 

Connecting the VC-3200 to a PC via RS-232C interface enables storing the measured data and so on.
 

By connecting a pair of commercially sold headphones to the VC-3200, it is possible to make hearing check of the vibrating sound. Moreover, it can be used instead of conventional stethoscopic probe. Output signals are provided for each band, enabling an observation for vibration phenomenon on each frequency band separately.