A method for controlling a light intensity in an enclosed cultivation space, the enclosed cultivation space having a light regulating system including an artificial light source for emitting artificial light, the method comprising, detecting a first fluorescence gain and a second fluorescence gain at different light intensity operating points. If the fluorescence gain is greater when the light intensity is greater, then the light intensity setpoint can be increased. Similarly, if the gain is greater when the intensity is lower, then the setpoint can be reduced.

The invention is based on the understanding that it is beneficial for plant growth to provide light at a level which corresponds to a maximum ChlF-gain. The light level which corresponds to a maximum ChlF-gain provides a good trade-off between production rate and production efficiency.

A calibration attachment for adjusting, calibrating, and/or performing a functional check of an optical sensor, which is configured to measure at least one measured variable in a medium by light, wherein the sensor is designed to emit transmitted light of at least one wavelength in the range of 200-700 nm, in particular 200-500 nm, includes a housing and a body, which is arranged in the housing, wherein the body includes praseodymium and cerium, and wherein the body, after excitation with the transmitted light, emits light of a different, in particular longer, wavelength. A sensor arrangement includes such a calibration attachment and use thereof.

A side illuminated multi point multi parameter optical fiber sensor that requires no sensitive coating is provided. This sensor comprises an optical fiber having at least one removed cladding section as the sensitive region, at least one probing light source that side illuminates the fiber, a power supply, a detector, a signal processor and a display. The sensitive optical fiber is optically affected by the presence of a measurand medium that can fluoresce, phosphoresce, absorb and/or scatter the probing light. This probing light is guided by the fiber core towards a detector which measures the light intensity and this light intensity is correlated with a measurand.

The present invention provides a post-fabrication modification approach for the fabrication of colored and chromic materials and sensors using plasma surface modification to covalently bind the coloring agent to the substrate, thus avoiding leaching of the dye. Advantageously, in said methods, said coloring agent is a dye or pigment linked to a radical sensitive functional group, such as an alkenyl or alkynyl functional group, and is applied to the substrate prior to the gas plasma treatment. The methods envisaged herein are generic in nature, which allow the covalent immobilization of various dyes on different materials. The covalently coated materials after plasma surface modification, particularly the covalently coated chromic materials and sensors, can be used in many different applications, such as protective textile and wound dressing applications.

A microalgae observation apparatus includes a flow cell 40 into which a fluid containing microalgae is introduced, an excitation light source 10 configured to irradiate the flow cell 40 with excitation light, a first fluorescence detector 102A configured to detect lipid autofluorescence emitted from lipid of each of the microalgae irradiated with the excitation light, a scattered light detector 105 configured to detect light scattered from each of the microalgae, and a recording section 301 configured to time-sequentially record the intensities of the detected lipid autofluorescence and scattered light. The recording section 301 is included in, for example, a central processing unit (CPU) 300. The lipid of the microalgae is also called oil bodies. The microalgae observation apparatus may further include a display device 401 configured to display changes with time in intensity of autofluorescence emitted from the lipid of the microalgae.

A ballast water monitoring device and a method for detecting live phytoplankton are disclosed. The device comprises a chamber for receiving a sample, at least one light source to emit light towards the sample, a light detector to receive light from the sample and generate a light signal, and a controller. The controller is configured to control the at least one light source to emit a single pulse of light, calculate the variable fluorescence [Fv] of the sample in response to the pulse of light, at time intervals less than the duration of the pulse of light, compare the calculated variable fluorescence to a predetermined reference limit, and perform an action if the calculated variable fluorescence is greater than the predetermined reference limit.

A chlorophyll fluorescence measuring system having at least one spectrometer coupled to a data logger. The data logger provides direct control of the spectrometer and includes on-board memory for storage of target and reference spectrum data obtained by the spectrometer. The data logger may be coupled to an external computer that receives and analyzes target and reference spectrum data to determine SIF using a spectral fitting algorithm. The system may include a spectrometer aiming system coupled to and controlled by the data logger. The system may also include one or more environmental sensors configured to measure environment variables. The environmental sensors may be coupled to the data logger for control and data storage. The environmental data may be communicated to the external computer for use in the spectral fitting algorithm. The data logger may be connected to a network for remote monitoring and control.

Methods of determining and characterizing photosynthesis in plant parts of one or more plants includes capturing a plurality of images of the plant parts of the one or more plants with a sensor are provided. Fluorescence of the plant parts of the one or more plants can be measured by storing a sensor image of observed fluorescence. Light absorbed by the plant parts of the one or more plants can be estimated by observing red and/or infrared reflectance of the plant parts. A characteristic of photosynthesis such as linear electron flow in plant parts of the one or more plants can be derived using the measured fluorescence of the plant parts, the reflectance and the light absorbed by the plant parts, and/or the three-dimensional model comprising the plant parts of the one or more plants. Related apparatus and systems are also provided.

A side illuminated multi point multi parameter optical fiber sensor that requires no sensitive coating is provided. This sensor comprises an optical fiber having at least one removed cladding section as the sensitive region, at least one probing light source that side illuminates the fiber, a power supply, a detector, a signal processor and a display. The sensitive optical fiber is optically affected by the presence of a measurand medium that can fluoresce, phosphoresce, absorb and/or scatter the probing light. This probing light is guided by the fiber core towards a detector which measures the light intensity and this light intensity is correlated with a measurand.

An optochemical sensor for measuring luminescing analytes in a measurement medium includes a sensor housing, a light source, a functional element, a photodetector and a control unit, wherein the sensor housing includes a window suitable for coming into contact with the measurement medium, wherein the light source is configured to emit a stimulation signal in such a way that the stimulation signal is partially emitted onto the functional element and the stimulation signal is partially emitted through the window into the measurement medium as to stimulate a first analyte present in the measurement medium, wherein the functional element includes a reference dye that includes an inorganic material and is suitable for emitting a first luminescence signal upon stimulation with the first stimulation signal.