Field Application of a Level Transmitter Calibration in a FTL

The FTL(Fuel Test Loop) is the facility in HANARO that is designed in order to test a nuclear fuel at a very high temperature and pressure with the same condition as the primary system of a nuclear power plant. There are many process values in the FTL and particularly very sensitive values that should be controlled precisely need to be measured by an accurate method. Though the calibration of the instruments, it was found that the measurement at the field test was in discord with the bench test value. This is because there were unexpected conditions due to a field status. In the case of a few level transmitters installed, several offset are also found to some degree. Through many trials, we can find the cause of this offset. This problem is in the reference line position and detail content about this is described lower. And applied calibration method is also introduced