Patent ID: 6250152
Filing Date: 2001-06-26
Classification: G01F,G01N

Abstract:
A sensor arrangement for determining a condition of a liquid in a container and a level of the liquid in the container comprising:a first sensor having first electrodes forming a first measuring chamber communicating with the liquid in the container via an opening at a lower end of the first sensor, the first sensor supplying a first signal for use in determining an impedance of the first sensor and the condition of the liquid in the container when the first measuring chamber is filled with the liquid;a second sensor having second electrodes forming a second measuring chamber coupled to the first measuring chamber and communicating with the liquid in the container only via the first measuring chamber, the second sensor supplying a second signal for use in determining an impedance of the second sensor and the level of the liquid in the container when the second measuring chamber is partially filled with the liquid;a common housing in which the first and second sensors are disposed, with a lower end of the second sensor being disposed above an upper end of the first sensor, and with the second measuring chamber being coupled to the first measuring chamber and in communication with the liquid in the container via at least one opening that is disposed completely within the housing connecting the lower end of the second measuring chamber to the upper end of the first measuring chamber; whereby,means, coupled to the first and second sensors, receives the first and second signals, and determines the impedance of the first sensor from the first signal and the condition of the liquid in the container therefrom, determines the impedance of the second sensor from the second signal and the level of the liquid in the container therefrom, and calibrates the impedance of the second sensor.