Please refer to the reply from Yamano san as below.
1. We basically set up calibration standard and internally proceed detect static electricity 1 time per 2 months.
2. Pha san should obtain the lincese as static electricity detector if necessary to implement this job.
3. We look for reasonable digital static meter for internal checking.
4. Calibration should be done by 3rd party 1 time per year.
It is appreciated if you let me know whether the above can be proceed.