A method and apparatus for determining particle contamination of a process fluid is disclosed herein. In one example, a fluid resistivity measurement probe is provided. The system includes an upstream fluid conduit, a downstream fluid conduit, and a measuring section. The measuring section has a metal rod, and a ground electrode. The ground electrode surrounds and is coaxial with the metal rod. The upstream fluid conduit is coupled to a first end of the ground electrode. The downstream fluid conduit is coupled to a second end of the ground electrode. The metal rod and the ground electrode define a space therebetween. The space flows a fluid from the upstream fluid conduit to the downstream fluid conduit.

A fluid sensor system comprises a radio frequency transmitter with adjustable output power, a radio frequency detector proximal to the radio frequency transmitter; a constant current source, and a switch coupled between the radio frequency detector and the constant current source. A method of determining the identity of a fluid using the fluid sensor system includes immersing the sensor system in a first fluid, increasing a transmit power of a radio frequency (RF) transmitter of the fluid sensor system until an RF signal is detected by a RF detector of the fluid sensor system, and determining the transmit power of the RF transmitter that first resulted in a detection of the RF signal by the RF detector to be the transmit power that is required for detecting the RF signal in the first fluid.

A fluid sensor system comprises a radio frequency transmitter with adjustable output power, a radio frequency detector proximal to the radio frequency transmitter; a constant current source, and a switch coupled between the radio frequency detector and the constant current source. A method of determining the identity of a fluid using the fluid sensor system includes immersing the sensor system in a first fluid, increasing a transmit power of a radio frequency (RF) transmitter of the fluid sensor system until an RF signal is detected by a RF detector of the fluid sensor system, and determining the transmit power of the RF transmitter that first resulted in a detection of the RF signal by the RF detector to be the transmit power that is required for detecting the RF signal in the first fluid.

A fluid sensor system comprises a radio frequency transmitter with adjustable output power, a radio frequency detector proximal to the radio frequency transmitter; a constant current source, and a switch coupled between the radio frequency detector and the constant current source. A method of determining the identity of a fluid using the fluid sensor system includes immersing the sensor system in a first fluid, increasing a transmit power of a radio frequency (RF) transmitter of the fluid sensor system until an RF signal is detected by a RF detector of the fluid sensor system, and determining the transmit power of the RF transmitter that first resulted in a detection of the RF signal by the RF detector to be the transmit power that is required for detecting the RF signal in the first fluid.

In one example, a print substance detector can include a sensor pin, an actuator coupled to the sensor pin to adjust a distance between a surface of the sensor pin and a base portion of a print substance reservoir, and a controller to send instructions to the actuator to adjust the distance of the sensor pin based on an indication of an operation associated with the print substance reservoir.

A method and apparatus for determining particle contamination of a process fluid is disclosed herein. In one example, a fluid resistivity measurement probe is provided. The system includes an upstream fluid conduit, a downstream fluid conduit, and a measuring section. The measuring section has a metal rod, and a ground electrode. The ground electrode surrounds and is coaxial with the metal rod. The upstream fluid conduit is coupled to a first end of the ground electrode. The downstream fluid conduit is coupled to a second end of the ground electrode. The metal rod and the ground electrode define a space therebetween. The space flows a fluid from the upstream fluid conduit to the downstream fluid conduit.

An apparatus for processing a laboratory sample contained in a laboratory sample container is presented. The apparatus comprises an optical sensing unit for sensing a transmittance at different vertical positions through the laboratory sample container and a tip sensing unit having a tip. The tip sensing unit is adapted to provide a tip sensing signal (tLDS) depending on a position of the tip relative to the sample. The apparatus also comprises a process control unit adapted to control the secure and reliable pipetting of the laboratory sample in response to both the transmittance and the tip sensing signal (tLDS) provided by the tip sensing unit.

A hydration bladder fluid level detection system includes a pack having a hydration bladder removably secured therein; a display in communication with a power source and to attach to the pack, the display having; a high level indicator; and a low level indicator; a detector system, including a high level probe in communication with the high level indicator and to detect fluid at a first level in the hydration bladder; a low level probe in communication with the low level indicator and to detect fluid at a second level in the hydration bladder; and a power supply probe in communication with the power source and to complete an electrical circuit with the high level and low level probes as circuit components; fluid dropping below the first level deactivates the high level indicator by breaking a circuit leg running between the high level probe and the power supply probe; and fluid dropping below the second level deactivates the low level indicator by breaking a circuit leg between the low level probe and the power supply probe.

Embodiments generally relate to froth measurement apparatus, and related methods and systems. An example apparatus comprises: an elongate first housing portion; and a series of sensor probes positioned along the first housing portion, each of the sensor probes having a probe body extending away from the first housing portion by a distance and comprising first and second electrodes for measuring changes in electrical potential associated with froth and/or bubbles. The sensor probes comprise signal processing circuitry coupled to the probe bodies to receive analog output signals from the probe bodies and to generate digital output signals based on the analog output signals. The apparatus comprises at least one processor configured to receive the digital output signals or sensor information based on the digital output signals and configured to determine at least one froth parameter over a sampling period based on the digital output signals or the sensor information.

An apparatus for processing a laboratory sample contained in a laboratory sample container is presented. The apparatus comprises an optical sensing unit for sensing a transmittance at different vertical positions through the laboratory sample container and a tip sensing unit having a tip. The tip sensing unit is adapted to provide a tip sensing signal (tLDS) depending on a position of the tip relative to the sample. The apparatus also comprises a process control unit adapted to control the processing of the laboratory sample in response to the transmittance and the tip sensing signal (tLDS) provided by the tip sensing unit.