A detector testing system for testing a gas detector used in a heating, ventilation, and air conditioning, or refrigeration (HVAC\R) system including: a testing chamber configured to receive the gas detector through an orifice in the detector testing system, the testing chamber being configured to at least partially enclose the gas detector within the testing chamber; a receiving port fluidly connected to the testing chamber; and a target gas cartridge fluidly connected to the receiving port, wherein the target gas cartridge contains a known concentration of a target gas, wherein the receiving port is configured to deliver the target gas to the testing chamber.

Disclosed is a gas sensor for detecting a measurement target gas in a measurement gas atmosphere, including first and second sensor elements respectively installed in first and second inner spaces of first and second installation parts. The first and second sensor elements have respective heating resistors connected in series and each has a resistance value that varies with change in temperature thereof so that the concentration of the measurement target gas can be calculated according to a potential between the heating resistors of the first and second sensor elements with the application of a constant voltage. The first and second installation parts are located at such positions that allow a maximum temperature difference of 0.4° C. or less between the first and second inner spaces during change in atmosphere temperature from 0° C. to 80° C.

The invention relates to a dosimeter material for ammonia and/or amines, the indicator used, as well as processes for their manufacture and use, in particular for quality control of foodstuffs. The dosimeter material for ammonia and/or amines, in particular in the gas phase, comprises an indicator which undergoes an irreversible color change in the presence of ammonia and/or amines, and an immobilization matrix for the indicator that is permeable to ammonia and/or amines, wherein the immobilization matrix is water-impermeable, and wherein the indicator comprises a phosphorus porphyrin activated by covalent bonding to a silanol group and having the formula porphyrin-P(V)X.sub.3, wherein X is Cl or Br.

A corrosion prevention process to protect the piping of a dry pipe sprinkler system from corrosion is described. The process includes the selection and application of suitable corrosion inhibitors to interior portions of the piping. The corrosion inhibitors used in this process may include volatile corrosion inhibitors.

Disclosed is a gas sensor package. The gas sensor package comprises a package substrate, a controller on the package substrate, a plurality of gas sensors on the controller, and a lid on the package substrate and the lid comprising a hole extending between a first surface and a second surface of the lid, the first surface of the lid facing away the package substrate and the second surface of the lid facing toward the package substrate. The gas sensors sense different types of gases.

A method of operating a gas detection device including a capillary-limited, electrochemical gas sensor includes operating the gas sensor in a sensing mode during which a signal from the gas sensor is representative of a concentration of the analyte gas measured by the gas sensor and in an interrogation mode during which the gas sensor is electronically interrogated by applying an electric signal to the gas sensor to generate a non-faradaic current flow between a working electrode and a counter electrode without the application of a test gas, periodically entering the interrogation mode, measuring a parameter of a gas sensor output during the interrogation mode, comparing the measured parameter to one or more previously measured parameters, determining an operational state from the comparison, and returning the gas sensor to the sensing mode if the operational state is determined to be within a predetermined range.

Improved optical absorption spectroscopy of species having broad spectral features is provided by choosing frequencies to cover the spectral feature(s) of interest, where the frequencies are slightly adjusted as needed to avoid narrow spectral features from interfering chemical species (i.e., clutter). The resulting clutter avoidance provides improved optical spectroscopy of species having broad spectral features.

Disclosed is a gas sensor for detecting a measurement target gas in a measurement gas atmosphere, including: a first sensor element; a first installation part defining a first inner space in which the first sensor element is installed; and a casing accommodating therein the first installation part. The casing has an opening formed to introduce the measurement target gas into an inside of the casing. The first installation part has: a first gas introduction hole formed to provide communication between the first inner space and the inside of the casing; and a membrane member arranged to cover the first gas introduction hole and having permeability to water vapor and substantially no permeability to the measurement target gas. At least a portion of the first installation part in contact with the membrane member is made of insulating ceramic material or resin material.

A gas sensor may include a plurality of elements that are responsive to particular gases based at least in part on the temperature of the temperature sensitive element. A first of the elements may be a gas detection element heated to a temperature at which it is responsive to a gas of interest. A plurality of additional elements may be configured in a reference element network and heated to a temperature at which they are not responsive to the gas of interest but are instead responsive to other effects such as humidity. The reference element network output may be used to remove the other effects (e.g., humidity) from the gas detection element output.

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.