A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

Apparatuses and associated methods of manufacturing are described that provide a tip resistant optical testing instrument configured to rest on a surface. The optical testing instrument includes a shell defining a cavity for receiving a sample tube. The shell includes a bottom shell surface, wherein the bottom shell surface defines at least one support element, wherein the at least one support element is configured to engage the surface to support the optical testing instrument in a testing position, and a translational surface configured to engage the surface to support the optical testing instrument in an angled position. In an instance in which the optical testing instrument tilts from the testing position to the angled position, the translational surface is configured to engage the surface contacting the translational surface to prevent the optical testing instrument from tipping further and allow the optical testing instrument to return to the testing position.

Provided herein are an optical test platform and corresponding method of manufacturing the same. The test platform may include a shell defining a cavity for receiving a sample tube, a first aperture, and a second aperture. The first aperture and the second aperture of the shell may each be configured to optically couple the cavity with an exterior of the shell. The test platform may further include a first window and a second window embedded in the shell. The first window may seal a first aperture and the second window may seal a second aperture. The first window and second window may each permit the optical coupling of the cavity with the exterior of the shell. The first window and the second window may be optically coupled via the cavity, and the shell may prohibit optical coupling between the first window and the second window through the shell.

A method, computer program product, and apparatus are provided for controlling components of a detection device. The device may detect turbidity of liquid with sensors such as a density sensor and/or nephelometric sensor. A light modulation pattern may reduce or eliminate interference in sensor readings. Readings may be performed during off cycles of an illumination light to reduce interference but to provide improved visibility of a tube. Dark and light sensor readings may be performed with an emitter respectively off or on to account for ambient light in subsequent readings. Readings from the density sensor and/or nephelometric sensor may be used to calculate McFarland values. The device may be zeroed based on an emitter level that results in a sensor reading satisfying a predetermined criterion.

Instruments, systems, and methods for measuring optical density of microbiological samples are provided. In particular, optical density instruments providing improved safety, efficiency, comfort, and convenience are provided. Such optical density instruments include a handheld portion and a base station. The optical density instruments may be used in systems and methods for measuring optical density of biological samples.

An apparatus for detecting an ultraviolet blocking material includes a light receiver configured to acquire detection light from a target object; a spectrum signal generator configured to generate spectrum signals based on the detection light; and a processor configured to: select a reference wavelength from a range from about 290 nm to about 400 nm, and detect an ultraviolet blocking material based on a first spectrum signal of a first wavelength less than the reference wavelength and a second spectrum signal of a second wavelength greater than the reference wavelength, the first spectrum signal and the second spectrum signal being generated by the spectrum signal generator.

An optical gas sensor device includes the following. A light source emits an infrared ray to a gas as a detection target. An optical filter transmits the infrared ray with a wavelength corresponding to an absorption wavelength of the gas as the detection target. A light receiver generates a detection signal by detecting the infrared ray incident through the optical filter. A substrate is provided, and the light source and the light receiver are mounted on the substrate. A signal processor intermittently drives and controls on and off of the light source, and calculates a gas concentration value of the gas as the detection target from a difference value acquired by subtracting a detection value of the detection signal when the light source is off from the detection value of the detection signal when the light source is on.

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.

Detection of fluid conditions in an administration set. A light source is positioned to transmit an infrared light through administration set tubing and any fluid therein. A light sensor senses the infrared light transmitted through the tubing and generates an output signal. A frequency of the output signal is a function of an intensity of the light transmitted through the tubing. A processor receives and determines the frequency of the output signal, and compares the determined frequency to threshold frequency values to determine whether fluid is in the tubing. The processor also monitors the generated output signal to determine if the frequency of the output signal changes over time, and determines whether fluid is flowing in the tubing as a function of the determined change in frequency.

A fluid analyzer includes an optical source and an optical detector defining an optical beam path through an interrogation region of a fluid flow cell. Flow-control devices conduct analyte and reference fluids through a channel and the interrogation region, and manipulate fluid flow in response to control signals to move a fluid boundary separating the analyte and reference fluids across the interrogation region. A controller generates control signals to (1) cause the fluid boundary to be moved across the interrogation region accordingly, (2) sample an output signal from the optical detector at a first interval during which the interrogation region contains more analyte fluid than reference fluid and at a second interval during which the interrogation region contains more reference fluid than analyte fluid, and (3) determine from samples of the output signal a measurement value indicative of an optically measured characteristic of the analyte fluid.