You can search some useful topics inside TensorRT forum.
For example,
https://devtalk.nvidia.com/default/topic/1056739/tensorrt/does-tensorrt-python-api-support-uff-model-int8-calibration/post/5360226/#5360226
https://devtalk.nvidia.com/default/topic/1039120/tensorrt/sampleuffssd-int8-calibration-segmentation-fault/post/5324295/#5324295