Abstract: Methods for eliminating error in magnetic sensors used for measuring a coating thickness caused by static or changing external magnetic fields or temperature. The methods involve measuring an output voltage of a magnetic sensor, corresponding to an internal resistance of the magnetic sensor, in a static or changing magnetic field or external temperature, storing the value of the output voltage, performing mathematical operations with the stored value of the output voltage, and correcting the output voltage of the magnetic sensor to accurately indicate a coating thickness.

Abstract: The invention relates to a method which allows to compensate errors due to offset voltages and external magnetic fields when using a magnetic sensor for coating thickness measurement. Also a method is described which allows compensation of a temperature dependent change of the output voltage of the magnetic sensor.

Abstract: A method which compensates errors resulting from offset voltages and external magnetic fields when a magnetic sensor is used to measure coating thickness. The method also allows compensation of a temperature dependent change for output voltages of the magnetic sensor.

Abstract: The subject of the invention is a coating thickness gauge with at least one measuring probe (14) which has at least one sensor (15, 15′) as well as a device for the zero adjustment and/or calibration. The coating thickness device (10) is equipped with means to automatically activate zero adjustment and/or calibration when an interaction especially a contact or a relative movement between a sensor (15, 15′) and a reference plate (11, 11′).

Abstract: The invention relates to a method which allows to compensate errors due to offset voltages and external magnetic fields when using a magnetic sensor for coating thickness measurement. Also a method is described which allows compensation of a temperature dependent change of the output voltage of the magnetic sensor.

Abstract: An apparatus for determining paint damage including a magnetic-field responsive sensor and display elements. The sensor signal function of the thickness of the paint on a substrate is fed by a discriminator to one of at least two tracks in relation to the amplitude of said signal. A display element is assigned to each track and in the presence of a signal will display said track.

Abstract: A device for measuring the thickness of a layer of coating on a metal surface is disclosed. The device includes a housing, a first magnetic probe mounted on the housing for measuring the thickness of the layer on a metal substrate containing iron, and a second eddy current probe mounted on the housing for measuring the thickness of the layer on a metal substrate which does not contain iron. The first and second probes are physically separated from each other on the housing. A calculating circuit receives the output of one of the first and second probes and calculates the thickness of the layer as a function of the output of the one of the first and second probes. A display is coupled to the calculating circuit for displaying the thickness of the layer being measured.

Abstract: The invention relates to a process for absorbing ozone in water by introducing an ozone-containing gas into a water current streaming downward in an absorber, wherein the ozone-containing gas is introduced into the water current in the form of bubbles at the upper end of the absorber and subsequently conveyed downward to the absorber outlet in a direction opposed to its ascending direction.

Abstract: An improvement is provided in a device for measuring the thickness of non-magnetic layers on magnetic substrates by determining the adhesion of a magnet in contact with the layer. The device comprises a housing, a scale balance carrying the magnet at one end thereof, the scale balance being mounted rotatably on an axis, a manually rotatable disk and a first spring means connected to the scale balance at one end and to the scale disk at the other end. The scale disk and first spiral spring are coaxial with the scale balance axis. The improvement comprises drive means including a second spiral spring means which has one end attached to the casing and the other end attached to the scale disk. The second spiral spring is coaxial with the scale balance axis. The spring tension of the second spiral spring means is slightly greater than that of the first spiral spring means and counteracts the first spiral spring means.