On the vibration side most calibration requirements are based on mechanical systems. Accelerometers are not calibrated, they essentially just verify the calibration. For the most part the digital analyzers are the same.
Depending on your requirements, having a portable shaker and just verifying the sensors and analyzers should be fine, if an accelerometer is out of range you replace it, if the analyzer is you send it in to be calibrated.
If you are heavily regulated industry like nuclear, you may be stuck doing the calibration, it will all depend on your requirements.