The handheld adapter for curved surfaces is used for hand-arm vibration measurements with the PCE-VM 31. It is is designed for use with the KS903.10 hand-arm acceleration sensor. When performing a measurement, you push the adapter against the handle with your hand.
The hand-arm acceleration sensor KS903.10 can be connected to the PCE-VM 31 in order to perform hand-arm human vibration measurements according to ISO 5349.