Abstract: The present disclosure is related to a catalyst for PIR/PUR foam production comprising a compound having the general formula (I) wherein R1 and R2 are independently selected from a C1-C18 straight-chain or branched alkyl group, unsubstituted or substituted with one or more hydroxyl, amino or aminoalkyl groups, or R1 and R2, taken together, form a 5- or 6-membered ring or 7-membered bicyclic structure, one of the members of the ring or bicyclic structure being X, wherein X is selected from CH2, O, S, NCH3 or NCH2COOM, wherein R3 and R4 are independently selected from hydrogen or a C1-C4 straight-chain or branched alkyl group and wherein M is an alkali metal ion or a quaternary ammonium ion, as well as to a process for production of said compound and uses thereof and to a process for the production of PIR/PUR foam or flexible foam in the presence of the catalyst of the present disclosure.

Abstract: The invention relates to an arrangement for measuring the concentration of gaseous and/or vaporous components of a fluid mixture by means of light absorption such as by means of an infrared absorption by utilizing a membrane which is made of a material in which the component of the fluid mixture to be measured accumulates. The membrane is transparent to the measuring radiation and is selectively permeable for the particles of the compounds to be measured. The membrane further acts on the radiation path between the light source and the detector. The arrangement is improved with respect to selectivity and the detection sensitivity. This is achieved in that the membrane is mounted in the flow path of the fluid mixture such that the flow path is subdivided into two component paths at the surfaces of the membrane.