I have had several discussions concerning measuring acceleration and/or vibration in 3 axes. There are several ways to accomplish this:
The B, BD, and BDK single axis accelerometers can be mounted in a tri-axial formation using either the SW3 Mounting Cube or the BS24 Mounting Cube. The BS24 is smaller than the SW3 and allows the user to move the sensor around on the block and switch out sensors to change the range or replace with a new sensor. The SW3 format is a permanent configuration, if one sensor is damaged the entire unit must be replaced. Please note, the BS24 is limited as far as its compatibility, accepting only the B Series or NB3 Sensor with special threading.
Another option is the SB3Gi. This is an out of box solution using a die-case aluminum IP65 housing with 3 integrated accelerometer sensors with 3 signal conditioners. This factory calibrated package provides 3 analog current 4-20mA 2-wire current loop outputs, powered by an 8-30VDC non-regulated supply.