Type 4250

Volume velocity sources (VVS) are used as ‘acoustical shakers’ to measure acoustic frequency response functions – sound pressure per unit volume velocity – typically in connection with noise source contribution analysis. Uniquely, HBK volume velocity sources use a special dual-microphone probe to measure accurate volume velocity directly in real time.

HBK 4250 wideband volume velocity sources cover the full acoustic frequency range with two powerful drivers to maximize signal-to-noise in real-world conditions, and three probes providing calibrated volume velocity in the low-, mid-
and high-frequency ranges.

The driver units are designed to handle real-world measurement scenarios with high transmission loss or background noise that cannot be reduced, such as in outdoor situations.
Built-in overload protection ensures robust performance.

When used with BK Connect® software, volume velocity is monitored and measured in real time. Vibro-acoustic frequency response functions – sound pressure per unit force – can be measured using the reciprocal method and acceleration per unit volume acceleration.