Oil pressure meter circuit.
– Signal wire
Exhaust temperature meter circuit.
fuel tanks, and the one advantage is that
they are well damped; fluctuating meter
readings with fluid movement are reduced
by the damping effect.
The lever-type sensor comprises a sensor head installed on the end of an adjustable arm. The sensor head has a variable-resistance and float-arm pivot. As the float
and arm move relative to the fluid level, the
resistance changes, and the meter reading
shows the actual level.
The capacitive sensor operates on the
principle that the value of a capacitor is
dependent on a dielectric between plates.
The sender unit measures the capacitance
difference between air and the liquid. The
sensing circuit outputs a voltage proportional to the level in the typical range of 0
to 5 volts.
Within an electric-gauge system, a
voltmeter or ohmmeter is scaled, or graduated, to display the voltage or resistance
output from a transducer or sender unit.
The VDO range characterizes this type
of meter. In a diaphragm-based mechanical system, the meter connects to capillary tubing and operates using vapor
Shunt ammeter meter connection.
pressure to mechanically change the
meter via the diaphragm. These types
may also incorporate electrical alarm contacts within the meter, and are characterized by the Murphy Swichgage range
Many instrument panels incorporate
a voltmeter to show the level of the charging voltage. Charging voltmeters have a
colored meter scale to allow a quick view
of conditions, a red zone for under- or
overcharge, and green zone for proper
The in-line, or series, ammeter has
the main charging alternator output cable
connected directly to it and then to the