The article describes the automation of the resistivity measurement for fly ash. Fly ash resistivity is an important consideration in the operation of particulate control devices based on electrostatic principles (the higher the resistivity of the fly ash, the more difficult it is to collect). Because of the need for characterization of fly ash resistivity and the large amount of time required to conduct the manual test, it was decided to automate the test. A standard (STD) bus computer was used in the automated test to monitor the temperature, collect current readings, and transfer the data to a personal computer. The personal computer was programmed to calculate and plot the results from the data received from the STD computer. The automated system tracks the manual system closely. It also consistently produces smoother curves and is very precise for duplicate runs. Most importantly, operator time for the test was reduced from about 6.5 hours per test to about 1 hour, thereby improving productivity.