A method for indicating the level of a liquefied gas in a cryogenic tank having a resistance temperature detector (1). The controller applies a heating pulse to the detector and performs a single resistance measurement after the heating pulse. The overheating of the sensor and the time interval for the measurement are found in a separate set of test experiment. As a result, for temperature sensors with negative temperature coefficient, the resistance of the sensor in gas is below some unique characteristic value, which can be used like a threshold criterion to distinguish between the liquid and the gas in a wide temperature range. For sensors with positive temperature coefficient, the resistance of the sensor in gas is larger than some unique characteristic value, which can be used like a threshold criterion to distinguish between the liquid and the gas in a wide temperature range.

This disclosure describes integrated circuits which may be provided in logic circuitry packages and/or replaceable print apparatus components with print material reservoirs. An integrated circuit or logic circuitry package for a replaceable print apparatus component comprises an interface to communicate with a print apparatus logic circuit and at least one logic circuit.

The invention relates to devices for detecting the fill level of media in containers. The devices are distinguished, in particular, by a simple and reliable detection of the fill level. For this purpose, multiple measuring points, each consisting of a series circuit of a resistor and a p-n junction, are spaced apart from one another. Each measuring point is connected, on the one hand, to an input of a multiplexer. On the other hand, the measuring points are connected to a reference potential. The output of the multiplexer is connected to a control device, wherein the control device is a control device periodically supplying a voltage to the measuring point connected to the control device via the multiplexer and measuring the voltage drop, a control device determining the medium from the temperature-dependent forward voltages resulting from the different thermal properties of the medium and a control device ascertaining the fill level from the consecutive measuring points.

A logic circuitry package includes an interface to communicate with a print apparatus logic circuit and at least one logic circuit including at least one heater and a temperature sensor. The at least one logic circuit is configured to receive, via the interface, a heater command to address the at least one heater. The at least one logic circuit is configured to receive, via the interface, subsequent to the heater command, a sensor command corresponding to a sensor ID to address the temperature sensor. The at least one logic circuit is configured to transmit, via the interface, a digital value in response to the sensor command. The digital value corresponds to a print material level of a print material within a reservoir.

In some examples, a liquid container comprises a chamber forming a volume containing a liquid, an elongated strip extending into the volume containing the liquid, a plurality of heaters supported by the strip along the strip, and a plurality of temperature sensors supported by the strip along the strip. The temperature sensors output signals indicative of dissipation of heat from the heaters to indicate a level of the liquid in the volume.

A fluid property sensor may comprising an integrated circuit (IC) including a fluid level sensor, and/or a pressure sensor; and an external interface electrically coupled to a proximal end of the EC, wherein the pressure sensor may be configured to measure a flexure of the fluid property sensor.

This disclosure describes integrated circuits which may be provided in logic circuitry packages and/or replaceable print apparatus components with print material reservoirs. An integrated circuit or logic circuitry package for a replaceable print apparatus component comprises an interface to communicate with a print apparatus logic circuit and at least one logic circuit.

A logic circuitry package for a replaceable print apparatus component includes an interface to communicate with a print apparatus logic circuit, and at least one logic circuit to receive, via the interface, requests corresponding to different sensor IDs with the component connected to the apparatus. The logic circuit is to transmit, via the interface, a digital value in response to each request. The digital values corresponding to the different sensor IDs are distinct.

Disclosed is a method for gauging the liquid propellant tank of a spacecraft during a phase of high-thrust along an axis, the tank being thermally conductive and having a known geometry. The method includes steps of: attaching, on a wall of the tank, a heating member and at least one temperature sensor in proximity to the heating member and in a plane of interest perpendicular to the thrust axis; during the high-thrust phase, heating the wall of the tank and acquiring temperature measurements of the wall of the tank at rapid frequency; determining the instant I when the temperature measured by the sensor changes, such change indicating the presence of the liquid-gas interface in the tank in the plane of interest; and determining the volume of liquid propellant present in the tank at instant I.

A print material level sensor comprises a series of print material level sensing devices disposed at intervals to detect presence of a print material at successive depth zones in a container, wherein each print material level sensing device includes a heater to emit heat at its depth zone and a sensor to sense heat at the depth zone and to output a signal based on the heat sensed. The sensor has control circuitry to, for each print material level sensing device to be calibrated, turn on the heater for an initial time duration set by an initial heat count and iteratively adjust the time duration for which the heater is turned on in accordance with an adjusted heat count, until the signal output from the sensor indicates that a target value has been reached in that depth zone.