摘要 |
An opto-electric levelmeter having a sensor that provides an output signal whose frequency represents the surface level of liquid in a container. The sensor's circuitry includes an oscillation circuit that uses "optical feedback" to modulate the sensor output signal. The signal is delivered to a monitor that provides an output signal for the user. The monitor also permit s adjustment for both high and low levels of a particular container. The monit or sends electrical energy to the sensor, and receives the sensor output signal on the same electrical link.
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