ISO 5347 comprises a series of documents dealing with methods for the calibration of vibration and shock pick-ups. This part of ISO 5347 lays down detailed specifications for the instrumentation and procedure to be used for base strain sensitivity testing. It applies to rectilinear accelerometers, mainly of the piezoelectric type. This part of ISO 5347 is applicable for the following parameters: a) Reference values: — pick-up base radius of curvature: 25 m — base strain: 2,5 × 10−4 b) Check values: — radius of curvature 62,5 m, strain of base 1 × 10−4 — radius of curvature 12,5 m, strain of base 5 × 10−4