Abstract: Systems and methods for providing an ultra-stable measurement of the density of a fluid/gas species such as ozone in a mixture. The technique is based on information extracted from multi-wavelength light absorption, at which the species exhibits different absorption properties (coefficient values). The technique provides real-time compensation for short- and long-term instability in the light source and detector, and for detectable changes in the optical characteristics of the cell, thus improving the accuracy of the measurement while making frequent zeroing of the instrument unnecessary. In addition, the invention provides a high-performance technique for measuring ultra-high ozone densities using absorption at the Chappuis band.

Abstract: A gas detection and measurement system includes a light source, a light sensor, a test cell body having a first fluid port and a second fluid port, and first and second optical paths from the light source to the light sensor through the test cell. The first and second optical paths have different lengths. As fluid flows through the test cell body, light intensity measurements are taken along the first and second optical paths so that the concentration of a target gas within the fluid can be calculated.

Abstract: A gas detection and measurement system includes a light source, a light sensor, a test cell body having a first fluid port and a second fluid port, and first and second optical paths from the light source to the light sensor through the test cell. The first and second optical paths have different lengths. As fluid flows through the test cell body, light intensity measurements are taken along the first and second optical paths so that the concentration of a target gas within the fluid can be calculated.

Abstract: A gas measurement system includes a first test unit for measuring the concentration of a selected gas at a first location, a second test unit for measuring the concentration of the selected gas at a second location, and a comparator for comparing the measured concentration of the selected gas from the first location with the measured concentration of the selected gas from the second location. An alarm indication is provided when a difference between the first and second measurements is greater than a user defined value or percentage. In an exemplary embodiment, the gas measurement system is configured to detect an ozone leak.

Abstract: A radiation source directs light at a mirror which reflects to a first photosensor. As a dew point is reached, scattered light is reflected to a second photosensor to indicate dew point. Rather than periodically interrupting operation to test reflectivity of the mirror or to perform a heating cycle, operation is monitored continuously. The common mode output of both the first and second photosensors is monitored. When below a threshold level, the output indicates the need for cleaning the mirror. It may also be used in a closed loop to increase light source intensity as mirror reflectivity decreases.