Methods and systems for detecting and limiting the water in a photoionization detector are provided. The method may include powering off a lamp configured to ionize particles of air. The method may also include monitoring a signal from the photoionization detector. The signal may be monitored based on a current between a signal electrode and a bias electrode. In an instance the signal is above a signal threshold, the method may also include electrolyzing one or more particles of water present in the photoionization detector by closing a leakage switch in order to allow current to flow through the bias electrode and the signal electrode. In an instance the signal is below the signal threshold, the method may include powering on the lamp to begin photoionization detection. Corresponding systems are also provided.

A sensor is driven at a first heating power value. The sensor generates a sensing signal that is indicative of a sensed entity. A possible onset of a sensor contamination condition is detected as a function of the sensing signal generated by the sensor. If such detecting fails to indicate onset of a sensor contamination condition, the sensor continues to be driven at the first heating power value. However, if such detecting indicates onset of a sensor contamination condition, a protection mode is activated. In the protection mode, the sensor is driven at a second heating power value for a protection interval, where the second heating power value is lower than the first heating power value. Furthermore, the operation may refrain from supplying power to the sensor for a further protection interval, wherein the further protection interval is longer than the protection interval.

A method for measuring pollution that includes providing a plurality of analyte sensors arranged in a grid over a sensing area, wherein the analyte sensors measure a pollutant, and positioning at least one current sensor in the sensing area. A pollution source is localized using a pollution source locator including a dispersion model and at least one hardware processor to interpolate a location of a pollution source from variations in current measured from the current sensors and measurements of pollutants from the analyte sensors.

Disclosed herein is a quantifying method of uncertainty of measured value by close match span calibration of measuring sensor comprising a step of: a quantifying using below equation I. $\begin{array}{cc}{u}_c\left(x_{\mathrm{bag}}\right)\simeq \sqrt{{\left[\frac{1}{f_{\mathrm{cyl}}}u\left(R_{\mathrm{bag}}\right)\right]}^2+{\left[\frac{1}{f_{\mathrm{cyl}}}u\left(R_{\mathrm{cyl}}\right)\right]}^2+u^2\left(x_{\mathrm{cyl}}\right)}& \left(I\right)\end{array}$ wherein, u.sub.c is a combined standard uncertainty, X.sub.bag is a measured value of a test, x.sub.cyl is standard value, f.sub.cyl is standard response factor (sensitivity coefficient), R.sub.bag is a signal value of a test, represents x.sub.bag.Math.f.sub.bag, R.sub.cyl represents x.sub.cyl.Math.f.sub.cyl, and u is standard uncertainty.

A method includes attaching a gas capture device to a bypass system adjacent to a gas meter. The method also includes rotating an internal cartridge near the gas meter to a bypass mode. The rotation of the internal cartridge enables gas to be diverted through a bypass system and away from the gas meter into an outlet. Remaining gas is captured from the gas meter to prevent the gas from releasing externally. The gas meter is removed from its original position. The internal cartridge is rotated from the bypass mode to a purge mode.

There is provided a gas sensor system including a first gas sensor apparatus including a transmission unit configured to transmit first calibration information and reliability information of the first gas sensor apparatus, and a second gas sensor apparatus including a reception unit configured to receive the first calibration information and the reliability information and a calibration unit configured to calibrate, based on the first calibration information, a gas concentration of a second gas sensor, in which when the calibration reliability of the first gas sensor apparatus is higher than a reference calibration reliability, the calibration unit is configured to calibrate, based on the first calibration information, the gas concentration of the second gas sensor.

A gas analyzer includes: a column that separates a component in a sample gas; a valve that switches, between a test sample gas and a standard sample gas, the sample gas to be supplied to the column; a valve that adjusts an introduction amount of the sample gas to be supplied to the column; a detector that detects, by gas chromatography, the component in the sample gas separated by the column; and a control device. The control device controls the valve to allow the introduction amount to be a predetermined amount, calculates a peak area value of a chromatogram obtained by the detector when the introduction amount is the predetermined amount, and calculates a correspondence between the introduction amount and the peak area value.

A method for monitoring a gas sensor (14) which comprises two electrochemical measuring cells (20, 30) and which is arranged in an exhaust tract (10) of an internal combustion engine (11), wherein the sensor elements (20, 30) exhibit a substantially identical sensitivity towards a first gas component and a different sensitivity towards a second gas component and are insensitive towards further gas components. In an operating state in which an exhaust gas stream at the gas sensor (14) contains less of the second gas component than of the first gas component a concentration of the first gas component is calculated from each of the sensor signals from the sensor elements (20, 30) and a defect in a sensor element (20, 30) is deduced from the concentrations of the first gas component.

Devices, systems and methods for using system-level malfunction indicators to monitor the operation and resiliency of the autonomous driving system components are described. One example of a method for diagnosing a fault in a component of an autonomous vehicle includes receiving, from an electrical sub-component of the component, an electrical signal, receiving, from an electronic sub-component of the component, a message, and determining, based on the electrical signal and the message, an operational status of the component.

An air quality measurement unit comprising: a housing having an inlet for receiving an air flow and an outlet for venting said air flow; a plurality of sensors positioned in said housing forming an array of sensors, each sensor having a sensor inlet for receiving a portion of the air flow and a sensor outlet for venting said portion of air flow; each sensor arranged to measure an air quality parameter; wherein said sensors are placed such that the sensor inlet is positioned adjacent to the inlet.