This disclosure relates generally to analytical instruments for measuring one or more properties of specimens or samples to be analyzed and, more particularly, to an analytical instrument with an adjustable optical path length. An analytical instrument may include a specimen support upon which a specimen may rest and a compression plate for controllably adjusting an optical path length of the specimen between the specimen support and the compression plate. In particular, a specimen may contact both the specimen support and the compression plate such that controlling a distance of the compression plate with respect to the specimen support effectively controls the optical path length of the specimen. An analytical instrument may include collimating lenses to collimate electromagnetic energy for transmission through a specimen and converging lenses for directing electromagnetic energy transmitted through the specimen into one or more sensors.

A diffusion chamber for determining different parameters of an aqueous substance includes a vertical central cylinder having a sample chamber for receiving a substance sample and a needle-shaped pH-measuring sensor having a measuring tip which is brought into contact with the substance sample. A spectrophotometer having glass-fiber optics is configured to penetrate the substance sample. A gas supply into the sample chamber is configured to provide a variable gas exposure of the substance sample when determining parameters. A needle of the pH-measuring sensor is inserted into an obliquely extending groove of a slid-in sample slide. A sealing ring on the sample slide is pressed against the central cylinder by means of an inserted spacer ring, the sample chamber is tightly sealed with respect to gases from the surroundings of the diffusion chamber, and a minimum distance is maintained between the lower collimating lens and the substance sample.

An apparatus and a method are disclosed for performing a light-absorption measurement of a specified amount of sample. A method for performing a light-absorption measurement of a specified amount of sample includes placing the sample on the surface of an apparatus including the surface and a light reflector, the light reflector being mechanically coupled with the surface and separated from the surface by a separation distance, changing the separation distance, while the light reflector remains mechanically coupled with the surface, to a first separation distance, and performing a first light-absorption measurement of the sample via the apparatus, while the separation distance is equal to the first separation distance, and while the sample is subject to pressure force.

An apparatus includes a first pedestal surface coupled to i) a swing arm and to ii) a light source. The apparatus further includes a magnet, a base plate, a mechanical stop coupled to the base plate, and a second pedestal surface mechanically coupled to said base plate and configured to receive a liquid sample, said second pedestal surface being coupled to a spectrometer. The apparatus further includes a magnetic flux sensor located between north and south magnetic flux fields of the magnet such that the magnetic flux reaching the sensor while the mechanical stop is in physical contact with the swing arm provides a linear range of output of the magnetic flux sensor, and a processor adapted to calibrate the point for minimum optical path length using a threshold magnetic flux field emitted from the magnet and detected by the magnetic flux sensor.

An image analysis system includes a video camera that collects YUV color images of a liquid sample disposed between a capital and a pedestal, the color images being collected while a light source shines light through an optical beam path between the capital and the pedestal, and a processor adapted to i) obtain from the YUV color images a grayscale component image and a light scatter component image, and ii) obtain at least one binary image of the grayscale component image and at least one binary image of the light scatter component image.

One example of the present disclosure relates to an apparatus for spectroscopic analysis of residue. The apparatus includes a surface including a hydrophobic portion and a hydrophilic portion. The hydrophobic portion surrounds the hydrophilic portion. The hydrophilic portion includes a dimension equal to or larger than a width of a first incident non-destructive electromagnetic beam.

The invention relates to a device (10, 10) for the light-spectroscopic analysis of one or more liquid samples, comprising a light source (11) for generating and emitting light along a single light path (100), comprising a first sample holder (12) having a receptacle point (20) for the smallest quantities of a first sample, which is arranged in the light path (100) such that light radiates through the first liquid sample, comprising a second sample holder (13) for a second sample, which is arranged in the light path (100) such that light radiates through the second liquid sample, and comprising a detector (14) for detecting the light coming from the sample holders (12, 13).

The invention relates to a device (1) for the light spectroscopic analysis of a small amount of a liquid sample, comprising a receiving point (3) for receiving small amounts of the liquid sample, and light conductors (5, 6) which guide light of a light source to the sample and guide signal light from the sample in the direction of a detector, and is characterised in that an illumination source (7) is arranged below the receiving point (3), and a region (8) below the receiving point (3) which is permeable for the light of the illumination source (7), is provided such that the illumination light illuminates the receiving point (3).

A digital microfluidic (DMF) system, DMF cartridge, and method including integrated refractive index (RI) sensing is disclosed. The digital microfluidic DMF system and DMF cartridge may include, for example, a RI sensor (or sensor surface) directly in the droplet operations gap of a DMF cartridge. The digital microfluidic DMF system may include, for example, the DMF cartridge, one or more illumination sources, one or more optical measurement devices, and a controller. Additionally, a method of using the DMF system and DMF cartridge that includes integrated RI sensing is provided.

A sample holder (10) comprises: an upper layer (20); a lower layer (40); a middle layer (30) between the upper and lower layers; and a sample chamber (33) formed by a through-hole in the middle layer (30), covered at its upper extent by a portion of the bottom surface of the upper layer (20), and at its lower extent by a portion of the top surface of the lower layer (40), wherein at least part of the bottom surface of the upper layer (20) overlapping a portion of a top periphery of the sample chamber (33) comprises a hydrophobic surface, wherein the hydrophobic surface is sufficiently hydrophobic that a contact angle of a water droplet on the hydrophobic surface would exceed 110.