What is meant by Transverse Sensitivity of a Vibration Sensor?
We live in a 3 Dimensional world. Objects are free to move along X, Y and Z coordinates. For any movement happening in X direction - Y and Z become the Transverse directions. Similarly, for any movement happening in Y direction - X and Z become the transverse directions.
Thus, in vibration sensors - especially single axis sensors - when we coin the term transverse sensitivity - we tend to imply the amount of signal the sensor is likely to pickup from the transverse directions.
For example, if we have an accelerometer facing a Vertical Vibration of say 10 mm/sec RMS, then we want the instrumentation to read 10 mm/sec RMS. But, the accelerometer could be having a transverse sensitivity of 5% and the horizontal vibration could be 5 mm/sec RMS. So, in place of picking up 10 mm/sec RMS - the vibration sensor will pick up 100% of Vertical + 5% of Horizontal = 10 + (5 x 5/100) = 10 + 0.25 = 10.25 mm/sec RMS. This is the effect the transverse sensitivity has on final reading.
It is desirable to have transverse sensitivity of less than 5% in Vibration Sensors. All Accelerometers, Velometers and Vibration Sensors in General sold by IRD have Transverse Sensitivity of less than 5%