| 摘要 |
<p>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 permits adjustment for both high and low levels of a particular container. The monitor sends electrical energy to the sensor, and receives the sensor output signal on the same electrical link.</p> |
