Development of the Automation System for Mobile Gamma Scan Tomography Device to Measure Scaling in Geothermal Pipelines

Scaling in pipelines has become a major issue, resulting in creating financial losses for geothermal industries and uneven distribution of electricity in Indonesia. An automation system prototype for a mobile gamma scan tomography device has been developed to carry out scaling measurement within geothermal pipelines. This aims to preemptively address potential scaling-related issues, enhance work efficiency, and ensure the safety of workers from radiation exposure without disrupting ongoing production activities. The automation system is designed with Arduino Mega 2560 as microcontroller and radiation counter, stepper motors as actuators, NaI(Tl) scintillation detector for radiation detection, limit switch as the trigger for zero point position setup, Human-Machine Interface (HMI) display as the system interface, and microSD card to store radiation-counting data. The automation system will drive the detector and source collimator together to perform a radiation scan and counting along the pipe diameter. The radiation is scanned in 32 projections, achieved by executing translational and rotational movements. The automation system was examined through three kinds of tests: radiation-counting system test, translational movement test, and rotational movement test. The radiation-counting system test was performed by detecting radiation at 5 random points to test its stability and quality. Meanwhile, the translational and rotational movement tests were conducted by performing radiation scanning five times on each sample of the pipe diameter: 500 mm, 600 mm, and 700 mm. The results from the examination were analyzed using quantitative statistical methods: Chi square for the stability and quality of the radiation-counting system and the detector, as well as RMSE and Standard Deviation for the accuracy and precision value of the actuator. This research has successfully built an automation system prototype for a mobile gamma scan tomography device with the stability and quality of the radiation counting system falls within the acceptable range of 3.325 to 16.919 at 95% confidence level, accuracy value of 95.12% and precision value of 93.58% for its actuators.