The Most Accurate Way to Find pH

The most accurate way to measure pH is to use the pH meter. However, it was one of the methods that had some anomalies to the official pH for the substance. I chose it because if you get rid of the water on the probe, the probe would be very accurate, but I think the probe and substance was polluted from different classes and the water, so the pH with the probe was a little higher, never lower, than normal. The method that had the most difference was the universal indicator, and the one that had differences was the pH strips that also had a lot of anomalies.

The results I found on the internet were not all similar to the probe, but if the probes were washed, dried with a paper towel, and vacuumed, the results would have been much more accurate.