FLUID LEVEL DETECTION SYSTEM AND METHOD

摘要

A fluid level detecting system provides an input signal at a specific frequency to a sample in a container. A probe contacts the energized sample and provides a signal to a level sensing circuit. The level sensing circuit amplifies the signal from the probe and then bandpass filters, tuned to the specific frequency, the amplified signal. This filters out extraneous signals received from, for example, a cover on the container, and specifically identifies when the probe has contacted the sample fluid by comparing the filtered signal to threshold levels.

主权项

1. A method of detecting a location of a surface of a sample in a container, the method comprising:
coupling an input signal to one of a probe and an outer surface of the container; moving at least one of the container and the probe relative to one another such that the probe is directed into the container; detecting an output signal from the other of the probe and the outer surface of the container that is not coupled to the input signal; generating a processed signal as a function of the output signal; comparing the processed signal to a contact threshold level; and determining that the probe has contacted the sample surface when the processed signal is at least equal to the contact threshold level.