Figure 2-77. - Thermostatic fuel gauge, self-regulating.

Figure 2-78. - Thermostatic fuel gauge, externally regulated.

Figure 2-79. - Thermostatic fuel gauge, differential type.

are contained in the gauge. One of these coils is connected directly to the battery, producing a constant magnetic field. The other coil produces a variable field, whose strength is determined by a rheostat-type tank unit. The coils are placed 90 degrees apart.

PRESSURE GAUGE

A pressure gauge is used widely in automotive and construction applications to keep track of such things as oil pressure, fuel line pressure, air brake system