How to read volume from a sight gauge
I have a 15 gallon kettle and am looking to add a sight gauge to it. I have been looking around and have come across a couple that I like. I would rather get a sight gauge that is encased in metal like the one here. However, I have not read in the description of this gauge or any like it (with the encasing) that include some kind of calibration labels. The only sight gauge I can find that include the labels is here. Am I missing something? Or are some manufacturers not including the labels?