Design Guidelines

Sizing

The height and width for a gauge is determined differently depending on whether the chart control for the gauge appears on a fluid page or a classic page:

The overall dimensions of the gauge area will be used and will need to hold all the elements that you choose to have along with the gauge graphic itself. This includes:

Top labels
Bottom labels
Metric labels
Legends

The more elements that you want to include in the gauge area, the smaller the gauge graphic will become. The gauge rendering software will try to make a best fit.

As you design your gauge, it's important to carefully consider what you want your gauge to contain and to review the results of your gauge as you use edge cases of small and large values and labels as well as most likely cases. Also, consider the design of your gauge in the context of the rest of the page in which the gauge will appear. For example, do other elements on the page provide enough context so that you can reduce or eliminate the use of labels and legends in the gauge area?

Scaling

You can use the GaugeMinimum and GaugeMaximum properties to provide the low and high points of your dial or status meter gauge. Knowledge of the nature of your data will help you determine an appropriate scale.

You’ll also want to consider for a gauge whether you want the gauge minimums and maximums to be static (for example, minimum of 0 and maximum of 100 because test results can only fall within that range), or whether you want them to be dynamic (for example, make the minimum half of the metric value and make the maximum 50% greater than the metric value.

Labels

Three types of labels can be placed in the gauge – a top label, a bottom label, and a label for the metric. The top and bottom labels are customizable – they can be any text you desire. The metric label will always be the numeric value of the gauge metric.

The labels can be positioned in different locations along with the gauge. Any label can be placed inside the gauge. Additionally, top labels can appear above the gauge, bottom labels can appear below the gauge, and metric labels can be positioned with the bottom label or below it.

Generally, it’s better to constrain the use of labels to the minimum needed. Labels will take up space from the gauge itself, making the gauge smaller, and too much text in a label can result in ellipses that don’t look good and can be difficult to read.

Reference Areas and Legends

You can provide additional context about the metric that you display in your dial gauge, LED gauge, or status meter gauge by associating an instance of the Threshold class to the gauge using the SetThreshold method (available with all gauge classes). On dial and status meter gauges, you can add bands of color to the gauge background, typically to help indicate whether the metric is low, medium, or high. On LED gauges the values in the threshold instance determine the color and direction of the LED.

For more information on using the Threshold class, see Using the Threshold Class.

A legend is available if you use thresholds. The legend will show the colors and descriptions of all reference areas on your gauge.

Tick Marks

Tick marks on status meter gauges can often provide useful context information but possibly at the cost of making the gauge appear busy and cluttered. You should try them to see if they work for your situation.