Method for automatic performance diagnosis and calibration of a photometric particle analyzer
AssigneeMagee Scientific Corporation
InventorsGrisa Mocnik, Anthony D. A. Hansen, Jeffrey R. Blair
Life of this patent
Estimating the term…
Abstract
A method is provided for diagnosing the operation of a photometric particle analyzer. The method may determine when the operation is degraded from normal operating conditions, automatically, and the result displayed locally as well as being transmitted to a remote observer. The present invention may be used by optical photometric particle analyzers, or by analyzers that measure other properties of particles collected on filters.
Claims31
A method of testing a photometric particle analyzer, where the photometric particle analyzer includes one or more light sources each emitting light at a corresponding wavelength or a corresponding range of wavelengths, where each light source has a controllable intensity, a filter to collect particles, a first light path from the light source through a collecting portion of the filter that may be exposed to particle laden-air to a first sensor that produces a first signal, a second light path from the light source through a reference portion of the filter to a second sensor that produces a second signal, and a third light path from the light source to a third sensor without passing through the filter, where said third sensor produces a third signal, said method comprising:
- selecting the number of wavelengths or ranges of wavelengths of the one or more light sources;
- obtaining a baseline measurement of the first, second, and third signals, where said obtaining obtains with first light path, second light path, and third light path, in the absence of particles, and where said obtaining includes:
- operating the light sources at the selected number of wavelengths or ranges of wavelengths, and
- recording the baseline measurement;
- using the photometric particle analyzer to sample particle-laden air;
- obtaining a test measurement of the first, second, and third signals for the photometric particle analyzer after using the photometric particle analyzer to sample particle-laden air by:
- replacing the collecting portion of the filter with a collecting portion that has not been previously used to collect particles,
- operating the light sources at the selected number of wavelengths or ranges of wavelengths, and
- recording the test measurement;
- and
- generating an output from a comparison of said baseline measurement and said test measurement,
- where said output is a diagnostic of the operation of the photometric particle analyzer.
A method of testing a photometric particle analyzer having one or more light sources each emitting light at a corresponding wavelength or a corresponding range of wavelengths, optics, a filter that may collect particulates, and sensors, including a first sensor, a second sensor and a third sensor, and a stored baseline measurement of one or more of the sensors obtained with clean optics and filter between said light source and said one or more sensors, said method comprising:
- selecting the number of wavelengths or ranges of wavelengths of the one or more light sources;
- providing light from the one or more light sources through a collecting portion of the filter that may be exposed to particle laden-air to the first sensor that produces a first signal;
- providing light from the one or more light sources through a reference portion of the filter to the second sensor that produces a second signal;
- providing light from the one or more light sources through the third sensor without passing through the filter, where said third sensor produces a third signal;
- and
- generating an output from a comparison of said first signal, said second signal, said third signal and the stored baseline measurement,
- where said output is a diagnostic of one or more of the first signal, the second signal, and the third signal of the photometric particle analyzer.
Dependencies are inferred from the claim text.