摘要:
A photodiode array spectrometer comprises an arry (40) of photosensitive elements for receiving a beam of light. Light impinging on a photodiode causes discharging of the associated capacitors. The capacitors are recharged periodically by a charge amplifier via a video line (30) by closing transfer switches (SW1, . . . , SW 768) associated with the photosensitive elements, repectively. The switches are group together in several segments which are independently addressable such that during a recharge scan only selected groups of photodioldes are recharged. The information which segments are to be sctivated, i.e. which groups of switches are to be closed, is contained in a segment control block (43). An integration control block (46) additionally permits to adjust the time intervals between successive recharge cycles separately for each selected segment. The invention permits to select regions of interest of the photodiode array for a specific application, whereas other regions are ignored for that application, leading to a reduced data rate with high spectral resolution and sensitivity.
摘要:
A sample detection apparatus (200) for detecting a fluidic sample flowing through a first flow cell (202) and flowing through a second flow cell (204) of a sample separation system (10), wherein the first flow cell (202) has a first path length (D) and the second flow cell (204) has a second path length (d) being smaller than the first path length (D), wherein the sample detection apparatus (200) comprises a data determining unit (206) configured for determining first data indicative of a first relation between a detection signal intensity and a concentration of the fluidic sample in the first flow cell (202), and configured for determining second data indicative of a second relation between a detection signal intensity and the concentration of the fluidic sample in the second flow cell (204), and a data combining unit (208) configured for combining the first data and the second data in accordance with a continuous weighting function to thereby derive a weighted relation between detection signal intensity and concentration of the fluidic sample so that the weighted relation continuously reduces the contribution of the first data and continuously increases the contribution of the second data with increasing concentration.
摘要:
A method of reducing the effects of varying environmental conditions on a measuring instrument includes thermally insulating a measuring unit such that the effects of variations of environmental conditions on selected components of the measuring unit are substantially reduced, while allowing dissipated heat generated within the measuring unit to leave the measuring unit. The method also includes controlling a first temperature in the measuring unit by means of a control loop which includes a temperature sensor and means to influence the first temperature in the measuring unit in such a way that temperatures at locations with selected components are kept substantially constant.
摘要:
A Method of correcting a multi-path absorbance measuring system is suggested. The multi-path absorbance measuring system has a plurality of n measuring path: The method is executed by correcting the signal of the measuring paths based on a determined linearization function.
摘要:
A photodiode array spectrometer for determining the spectral composition of a polychromatic beam of radiation comprises an array of photosensitive elements intercepting different wavelengths of the polychromatic beam of radiation. An output signal representative of the charge accumulated by a charge amplifier circuit is obtained each time a predetermined number greater than 1 of photosensitive elements is scanned such that the output signal is representative of the integral of a plurality of the amounts of radiation intercepted by a corresponding plurality of the photosensitive elements.
摘要:
A fluid separation system (10) for separating compounds of a sample fluid in a mobile phase comprises a detector (50) adapted to detect separated compounds by providing an optical stimulus signal to the sample fluid and receiving a response signal to the optical stimulus signal. The detector (50) comprises a light source (100) adapted to provide an output light beam (230) as the optical stimulus signal. The light source (100) comprises a plurality of light emitting elements (200, 200A, 200Z) each adapted to emit a light beam (210, 210A1, 210A2, 210Z1, 210Z2) having a respective wavelength, and a diffracting element (220). The plurality of light emitting elements (200, 200A, 200Z) are arranged that emitted light beams (210, 210A1, 210A2, 210Z1, 210Z2) impinging, on the diffracting element (220) are diffracted by the diffracting element (220) to form the output light beam (230).
摘要:
A Method of correcting a multi-path absorbance measuring system is suggested. The multi-path absorbance measuring system has a plurality of n measuring path: The method is executed by correcting the signal of the measuring paths based on a determined linearization function.
摘要:
A method for processing measuring data and a device to perform the method, wherein the measuring data can be determined by using a measurement system, more particularly a chromatographic analyzing system, for the measurement of measuring values that correspond to certain information about, or of, a technical process and that depend on at least two variables.
摘要:
A photodiode array comprises a plurality of n channels, each channel having a photodiode which is reverse biased such that it acts as a current source. Each channel further comprises an A/D converter for providing a digital output signal (DATA) which is representative o the photo current (Iph) provided by the photodiode and therefore of the intensity of the light impinging on the photodiode. The A/D converter comprises a controllable current source, an integrator circuit, a comparator for comparing the output signal (Vout) of the integrator with a predetermined signal (Vthreshold), a logic circuit for controlling the current source in response to the output signal (Vcomp) of the comparator such that Vout is kept within a certain range. Preferably, the current source provides current in the form of charge dumps to and/or from the integrator. The number of dumps in one direction is counted by a counter and is a digital measure of the photo current (Iph). The photodiode array is particularly useful in spectrophotometers since the provision of a separate A/D converter for each channel allow simultaneous processing of all the photosignals in the array so that spectra distortions arising from time delays in processing the photosignals are avoided.
摘要:
The invention concerns a method and device to carry out the method to provide quality control for a photosensor, especially a photodiode array, whose output signal depends on the intensity of an input signal formed by electromagnetic waves. The photosensor to be tested receives stimulation signals forming the input signals while the stimulation signal intensity of the stimulation signals is varied. The associated output signals of the photosensor to be tested are measured and recorded for evaluation purposes. The photosensor preferably receives at least two independently controllable, superposed individual stimulation signals with individual intensities. The different stimulation signal intensities of the individual stimulation signals are set with the aid of a controller coupled to stimulation signal source, and the output signals of the photosensor are measured and recorded using a measurement data recorder unit.