Patent ID: 8841925

Claim:
A method for testing a laboratory device, comprising: an electronic circuit for detecting a liquid level in a liquid container and a feeler, which can be advanced, and which is connected to the input side of said circuit, wherein the feeler can be advanced in the direction of the liquid in the liquid container and the feeler causes a capacitance change on the input side of the circuit upon immersion in the liquid, which triggers an output signal in said circuit wherein the following steps are executed for testing an electronic circuit of the laboratory device by means of simulating a detection of a liquid using a reference circuit [00011] having a series circuit of a first small capacitance and a second larger capacitance, the second capacitance being able to be short circuited by the switching procedure, the reference circuit specifying a smaller effective capacitance because of the series circuit of the first capacitance and the second capacitance: a. connecting an output side of said reference circuit to the input side of said electronic circuit, the reference circuit specifying an effective capacitance on the input side of said electronic circuit, b. triggering the testing by the application of a control signal to the reference circuit, the control signal causing an increase of the effective capacitance by a switching procedure, said switching procedure providing for a triggering of a short-circuit of the second capacitance so that only the capacitance of the first capacitance is active due to the short-circuit and that the effective capacitance is thus increased in relation to the effective capacitance; c. processing a corresponding predefined capacitance change by said electronic circuit and triggering of an output signal, d. analyzing this output signal, to allow a statement about the function of the electronic circuit.