Patent ID: 7325321

Claim:
A method for monitoring the alignment of a measuring instrument, comprising the steps of: providing a monitoring device for the measuring instrument, the monitoring device having an inclination sensor comprising a container filled with a fluid in which a visibly monitorable bubble is formed, a radiating element arranged on a first side of the bubble for emitting a radiation, a sensor element and a pair of reference elements arranged on a second side of the bubble for receiving the radiation, wherein the inclination sensor functions according to the principle of a spirit level and the radiating element and the sensor element define a sensor axis that passes through the bubble when the bubble is centered, the sensor element being flanked by the respective reference elements; measuring optically the position of the bubble by the steps of emitting a radiation and receiving the radiation at the sensor element and the reference elements; testing whether the intensity of the radiation is within a permissible range using the reference elements; and verifying that the monitoring device is functioning correctly by performing a function test automatically inside the monitoring device.