An inspection system is configured to inspect the condition of a braze joint formed within a structure, wherein the braze joint is formed from a braze filler material having a tracer material disposed therein. The inspection system includes an energy source for directing energy towards the structure, an energy detector for detecting information regarding the structure following interaction with the energy directed from the energy source, and a data analysis system for analyzing the information detected by the energy detector. The data analysis system is configured to distinguish the tracer material from the remaining materials forming the structure in order to determine a suitability of the braze joint.

A differential monitoring system of carbon dioxide levels within an associated building with a monitoring zone including a quantity of captured carbon dioxide and a reference zone that is spaced away from the monitoring zone. The differential monitoring system includes a first carbon dioxide monitoring inlet disposed within the monitoring zone. A second carbon dioxide monitoring inlet is disposed within the monitoring zone in spaced relation to the first carbon dioxide monitoring inlet and/or is disposed within the reference zone in spaced relation to the first carbon dioxide monitoring zone. A controller is operable to determine when a carbon dioxide level at the second carbon dioxide monitoring inlet exceeds a carbon dioxide level at the first carbon dioxide monitoring inlet by a predetermined differential threshold. The inlets can be part of an aspirated sampling system and/or part of a distributed sensor system. Methods of monitoring carbon dioxide levels are also included.

In a refrigerant circuit 12 using a zeotropic refrigerant, a gas leak amount is detected on the basis of the liquid temperature and the liquid pressure of a saturated liquid of the zeotropic refrigerant.

The present invention relates to a liquid leakage sensing device that is capable of dividedly detecting water and chemical solutions in sensing liquid leakage using electrolysis, determining the kind of the leaking liquid detected, and being reused, not disposable. According to the present invention, the liquid leakage sensing device includes: a liquid leakage sensor (10) having a first electrode (11) and a second electrode (12) made of a conductive metal in such a manner as to be facedly spaced apart from each other by a given distance; a voltage/current amplifier (20) adapted to vary a voltage and a current to apply the varied voltage and current to the liquid leakage sensor (10); a current sensor (30) adapted to detect a value of current flowing between the electrodes of the liquid leakage sensor (10); and a controller (40) adapted to controlledly output a voltage applied between the first electrode (11) and the second electrode (12) of the liquid leakage sensor (10).

The present invention relates to a liquid leakage sensing device that is capable of dividedly detecting water and chemical solutions in sensing liquid leakage using electrolysis, determining the kind of the leaking liquid detected, and being reused, not disposable. According to the present invention, the liquid leakage sensing device includes: a liquid leakage sensor (10) having a first electrode (11) and a second electrode (12) made of a conductive metal in such a manner as to be facedly spaced apart from each other by a given distance; a voltage/current amplifier (20) adapted to vary a voltage and a current to apply the varied voltage and current to the liquid leakage sensor (10); a current sensor (30) adapted to detect a value of current flowing between the electrodes of the liquid leakage sensor (10); and a controller (40) adapted to controlledly output a voltage applied between the first electrode (11) and the second electrode (12) of the liquid leakage sensor (10).

An HVAC system is provided having an air supply system, a refrigerant circuit configured to condition air in the air supply system, and an electrochemical sensor configured to detect a refrigerant leak from the refrigerant circuit.

A method for the detection of leaks in a heat exchanger having discrete first and second fluid flow paths is disclosed. The method comprising the steps of introducing a contaminant fluid into the first flow path (13) and testing for the presence of the contaminant fluid in the second flow path (14), wherein the pressure in the second flow path (14) is maintained below atmospheric pressure. The pressure in the second flow path may be maintained, for example, at between 0.1 bar (110.sup.4 N/m 2) and 1 bar (110.sup.5 N/m 2) below atmospheric pressure. Apparatus for carrying out the method is also disclosed.

The invention relates to a gas sensor (34) and a method for detecting gas in a test space (37) of a test chamber for conditioning air, in particular a temperature control chamber, a climate chamber or the like, and to a test chamber, the gas sensor having a sensor head (35) configured to be brought into contact with an atmosphere of the test space. The gas sensor is configured to detect a gas, in particular a refrigerant and/or a hydrocarbon, in the test space, the gas sensor having a transport tube (36) configured to transport a measuring gas from the test space to the sensor head.

A method for checking quality of a heat exchanger includes the steps of: performing a liquid pressure test for the heat exchanger including a first flow path and a second flow path adjacent to the first flow path by filling the first flow path and the second flow path with a liquid in a pressurized state; discharging the liquid from the first flow path and the second flow path; and promoting evaporation of the liquid remaining in the first flow path and the second flow path by reducing pressure inside each of the first flow path and the second flow path using a vacuum pump. The step of promoting evaporation of the liquid is performed to feed heated gas into the first flow path and the second flow path.

An HVAC system is provided having an air supply system, a refrigerant circuit configured to condition air in the air supply system, and an electrochemical sensor configured to detect a refrigerant leak from the refrigerant circuit.