A Linear Gauge is a chart that shows a single measurement value and uses few chart elements, such as legend, axes, grid. etc. They are mostly used for imitating real gauges like thermometers.
Here you can see a dashboard with two linear gauges standing for the temperature in the air and in the water in the resort. They look like real thermometers - a single axis with a degree-ticks with a temperature level filled with color. The value is doubled in the bottom of each gauge making it more evident. There is a text element over the circular gauge simulating a compass rose which shows the humidity percentage, and the circular gauge demonstrates the wind direction (305°) and its strength (6 m/s). These values are displayed in the center of the compass. This dashboard is created through the table layout, so the extra text elements are the parts of the HTML code put into the table.