An environmental severity measurement tool measures acceleration along 3 axes to determine shock and vibration affecting a downhole tool in which the environmental severity measurement tool is disposed. The environmental severity measurement tool includes a replaceable battery and electronics disposed within an external housing. A pin provides a way to ensure the environmental severity measurement tool is oriented in a known orientation. Data sampled by the tool can be downloaded from the tool to an external device through a connector port of the electronics. Software in the tool controls the operation of the tool and can be configured from an external device.