Dot pitch is used with CRT monitors to describe the distance between the center of two adjacent phosphors of the same color on the screen and is expressed in fractions of a centimeter such as .22cm. The smaller the dot pitch, the sharper the picture. However, manufacturers don't always tell the truth about dot pitch. Often, when you do the math, you will find that the dot pitch multiplied by the resolution doesn't match the physical dimensions of the screen.
According to salesmen in the CRT market, there are two different types of glass grilles. The first is a true hexagonal shaped honeycomb used by companies such as Hitachi. The second is a vertical bar-grill shape used by Sony. Both use a measurement called dot pitch. Dot pitch indicates the distance between the center of any single cell in the glass and the cell directly adjacent to it. Honeycomb shaped tubes are typically sharper and clearer than the vertical bar models with the same dot pitch because the distance is the same no matter which way you measure it. The cells up, down, left, right and diagonally are all the same distance apart. On the vertical bar tubes, the distance to the cells adjacent across the diagonal are farther apart than the ones to the left, or right, or even the top and bottom.