Chapter 15 Applications

Any type of analog device which must be monitored that has variable position, temperature, or illumination will typically be monitored with a sensor. For example: A variable throttle position will be monitored by a throttle position sensor.

Any type of digital device which must be monitored that has two positions (on or off, up or down, cold or hot, etc), will typically be monitored with a switch. For example: The master cylinder brake fluid level will be monitored by a fluid level switch; it is either too low or it is OK.   A float with a magnet attached to it floats on top of the brake fluid.  When the brake fluid level is too low, the magnet closes a tiny reed switch inside the switch housing.  The switch housing does not touch the brake fluid.