the method includes providing a portable self - contained calibration device to an electrofusion controller . the calibration device includes internal or external dummy loads to simulate real fittings to be fused and instructs the electrofusion controller to apply electricity to these dummy load . then , the calibration device uses a measurement sub - system to measure a pre - determined parameter . a microcontroller sub - system determines if there is a difference between the measured values and the expected values . if there is a difference , the calibration device adjusts the electrofusion controller &# 39 ; s memory . the calibration device repeats the measurement with a second independent measurement device to ensure accuracy .