A capacitive sensing system based on projected self-capacitance is suitable for use in printing systems/products to sense paper tray status. In example embodiments, a capacitive sensing system is adapted for sensing the condition/characteristics of paper in the paper tray, such as paper size, stack height and page count and paper dielectric. The capacitive sensing system can be configured with one or more shielded capacitive sensors incorporated into the paper tray, and oriented relative to the paper according to the paper condition/characteristic sensed.

An ultrasonic receiver receives ultrasonic waves reflected at a plurality of portions of the body of a person to be measured, and thus the person to be measured needs to input the approximate height of himself/herself. An electrostatic capacitance sensor includes a transmission electrode and a reception electrode. The electrostatic capacitance sensor measures a mutual capacitance between the transmission electrode and the reception electrode by a mutual capacitance method. A variable frequency pulse generator generates a pulse supplied to the transmission electrode. A control apparatus allows the variable frequency pulse generator to sweep the frequency of the pulse and allows the electrostatic capacitance sensor to measure the mutual capacitance to identify a frequency at which the measured mutual capacitance is minimized. The control apparatus obtains the height of a person to be measured on the basis of the identified frequency.

In a position measuring device (5) and a method for ascertaining positions of an object (3) to be measured, at least one capacitive position measuring sensor (7) provides a position measurement signal (P.sub.M) relating to the object (3) to be measured and at least one capacitive reference measurement sensor (14) provides a reference measurement signal (R.sub.M). The measuring sensors (7, 14) are connected to a computing unit (8) which is embodied to calculate a position signal (P) to ascertain the positions from the position measurement signal (P.sub.M) and the reference measurement signal (R.sub.M). As a result of interfering influences being contained substantially equally in the position measurement signal (P.sub.M) and the reference measurement signal (R.sub.M) as an interference signal (S), it is possible to determine and eliminate the interference signal (S) during the calculation.

An ice thickness measurement sensor 100 is provided to measure the thickness of ice extending from a circuit. The ice thickness measurement sensor comprises at least one capacitive sensor 150. The capacitance of the sensor 150 depends on the thickness of ice covering the sensor, because the presence of the ice changes the permittivity. The ice thickness measurement sensor may be used in a fluid pipe, for example to measure the thickness of ice extending from the inner surface of the pipe.

Examples provide a shelf location detection system. A shelf is supported by a shelf support arm engaging a notch in a smart shelf support member having a stack of resistors in series within the interior of the shelf support member. A plug on the support arm removably couples to the notch. A sensor detects a change in voltage across at least one resistor in the resistor stack. A location of the shelf on the smart shelf support member is determined using the detected voltage change. A controller on the smart shelf support member transmits the location to a controller on each accessory device on the shelf. The shelf can further include a plurality of resistors connected in series. The accessory device detects changes in voltage through the plurality of resistors and generates an estimated position of the accessory device on the shelf using the change in voltage data.

The present invention is a surface height distribution measuring device that measures a surface height distribution in a plate-shaped measurement object. The surface height distribution measuring device includes a non-contact distance measuring unit that measure a distance to a surface of the measurement object in a non-contact manner, a support moving unit that relatively moves the measurement object and the non-contact distance measuring units, and a plate-shaped member provided at a position where, during measurement, the plate-shaped member is in non-contact with the measurement object and is approximately parallel to the measurement object and at least partially covers the measurement object when viewed from a direction perpendicular to the surface of the measurement object.

Solutions for capacitive height sensing (CHS) can include a multi-phase charge-to-voltage (C2V) converter. In some examples, a measurement cycle may begin with a coarse phase using a first voltage step and transition to a fine phase using a second, smaller voltage step. Control logic can be configured to manage the voltage steps and integrate charge from a variable capacitor associated with a head gimbal assembly (HGA). In some embodiments, an offset circuit may be used to increase measurement sensitivity. An output signal based on the integrated voltage may be indicative of the HGA's height.