A system for sensing particulate matter receives a first plurality of electronic signals from a photodetector over a period of time, the first plurality of electronic signals associated with a first plurality of particles, wherein each of the first plurality of electronic signals has a respective amplitude, sorts the first plurality of electronic signals into a plurality of amplitude levels, determines a respective quantity of signals associated with each amplitude level, determine an average summation of the first plurality of electronic signals, performs a calibration using the average summation, receives a second plurality of electronic signals from the photodetector over a period of time subsequent to the calibration, the second plurality of electronic signals associated with a second plurality of particles, and determines a mass concentration of the second plurality of particles based on the second plurality of electronic signals.

Methods and apparatuses to image particles are described. A plurality of illuminating light beams propagating on multiple optical paths through a particle field are generated. The plurality of illuminating light beams converge at a measurement volume. A shadow image of a particle passing through a portion of the measurement volume at a focal plane of a digital camera is imaged. Shadow images of other particles in the particle field are removed using the plurality of illuminating light beams.

A suspension particle sensing apparatus includes a first flow channel, a suspension particle concentration sensor and a suspension particle filtering assembly. The first flow channel has a first entrance and a first exit. The suspension particle concentration sensor is disposed in the first flow channel, and is located between the first entrance and the first exit. The suspension particle filtering assembly is disposed at the first entrance, and includes a casing and a suspension particle filtering structure. The casing has a first opening and a second opening. The first opening is communicated with the first entrance of the first flow channel. The suspension particle filtering structure covers the second opening.

Methods and apparatuses to image particles are described. A plurality of illuminating light beams propagating on multiple optical paths through a particle field are generated. The plurality of illuminating light beams converge at a measurement volume. A shadow image of a particle passing through a portion of the measurement volume at a focal plane of a digital camera is imaged. Shadow images of other particles in the particle field are removed using the plurality of illuminating light beams.

A system (100) for sensing particulate matter includes a computing device (110) having a processor (114) and a memory (112) storing instructions which, when executed by the processor (114), cause the processor (114) to: receive a first plurality of electronic signals from a photodetector (108) over a particular period of time, the first plurality of electronic signals associated with a first plurality of particles, wherein each of the first plurality of signals has a respective amplitude (218), sort the first plurality of signals into a plurality of amplitude levels (220), determine a respective quantity of signals associated with each amplitude level (222), determine an average summation of the first plurality of signals (224), perform a calibration using the average summation (226), receive a second plurality of electronic signals from the photodetector (108) over a period of time subsequent to the calibration, the second plurality of electronic signals associated with a second plurality of particles (228), and determine a mass concentration of the second plurality of particles based on the second plurality of electronic signals.

A device and method for measuring precipitation, in particular snowfall or hail, which has a measuring chamber for receiving a precipitation particle, at least one light source for radiating the measuring chamber with light, and at least one sensor for sensing an intensity of the light radiating through the measuring chamber. At least two measurement areas, which are arranged one below the other, are provided in the measuring chamber, and the intensity of the light radiating through each of the measurement areas can be detected separately.

Apparatus and methods for determining information about at least one particle by measuring light scattered from the particles. Scattered light is combined with light from a light source to produce an optical interference signal utilizing a plurality of beam splitting functions. Scattered light signals are corrected for signal components which are not derived from particle scatter.

The present application relates to sensor systems for sensing mass concentration of particles smaller than a predetermined threshold in an air stream. Such systems may include an inlet (for receiving a total flow of air with particles) connected to a first splitter (for separating the total flow into a major flow and a minor flow), a joint where a first duct carrying the major flow and a second duct carrying the minor flow come together, and a sensor in the first duct for measuring the amount of particles smaller than the predetermined threshold in the major flow.

An observation apparatus (100) includes an observing optical system (101) capable of obtaining an image of a measurement target present in a gap included in a device (1). One end of the gap included in the device (1) is wider than the other end thereof, and upon light beam irradiation to the device (1), an interference fringe appears in the gap. The observing optical system (101) irradiates the gap included in the device (1) with a plurality of light beams having different wavelengths to cause a plurality of interference fringes to appear in the gap. Then the observing optical system (101) obtains an image of the plurality of interference fringes.

Disclosed herein are methods for analyzing cell kinematics in a nucleated cell culture from a time-series sequence of multiple fluorescence microscopic images of the nucleated cell culture. The method includes the steps of, (a) identifying every cell nucleus in each fluorescence microscopic image; (b) identifying every cell cluster using the cell nuclei identified in the step (a); and (c) tracking the cells and/or cell clusters using the cell nuclei and cell clusters identified for the fluorescence microscopic images in steps (a) and (b) respectively.