Does [Gauge] Size Matter?
The first thing to do it to check any operating manuals you have for your equipment for the correct range that needs to be indicated. A thumb rule to use is that the scale should be in the effective range from ¼ to 7/8 of the total range. For example, if you are using a 0-100 scale the effective range is between 25 and 87-1/2. Going below 25% of the scale may be difficult to read and going above 87.5% doesn’t leave much room over the top. This also allows the gauge to perform in its optimum range.
The size of the gauge is important so that the operator can read it at a glance. The larger diameter the face, the farther away it can be seen. One of the advantages of an analog style gauge is that an operator can see if it is in the correct range from a distance. Just like the dashboard of your car or truck – the speedometer is relatively large because that is what you check most often. The fuel tank level is smaller because you don’t need to check that as often. Common sizes for gauges are 1-1/2”, 2”, 2-1/2”, 3”, 4” and even larger. Make sure you use gauge marking labels such as Gauge RangeTM to show the correct operating range of the equipment. You can choose red, yellow and green to represent too high/too low, caution, and good-to-go.
Select the correct range and size for your gauges. This will help with the optimum performance of your equipment and make things easier for the operator.