TECHNOLOGY FOCUS - INSTRUMENTATION AND TESTING - Preferred Components: The apparatus comprises: a mobile apparatus; an automobile air-conditioning apparatus; refrigerated road transport equipment; a stationary air-conditioning system; a stationary heat pump system; and a stationary refrigeration system.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Composition: The composition further comprises: at least one compound comprising 1,1,1,2-tetrafluoro ethane or pentafluoroethane; a lubricant comprising polyol esters, polyalkylene glycols, polyvinyl ethers, mineral oil, alkylbenzenes, synthetic paraffins, synthetic naphthenes or poly(alpha)olefins; a tracer comprising hydrofluorocarbons, deuterated hydrocarbons, deuterated hydrofluorocarbons, perfluorocarbons, fluoroethers, brominated compounds, iodated compounds, alcohols, aldehydes, ketones and/or nitrous oxide; a compatibilizer; at least one ultraviolet fluorescent dye comprising naphthalimides, perylenes, coumarins, anthracenes, phenanthracenes, xanthenes, thioxanthenes, naphthoxanthenes, fluoresceins and/or their derivatives; at least one solubilizing agent comprising hydrocarbons, dimethylether, polyoxyalkylene glycol ethers, amides, ketones, nitriles, chlorocarbons, esters, lactones, aryl ethers, fluoroethers or 1,1,1-trifluoroalkanes; an odor masking agent; and a stabilizer. The composition comprises: 2,3,3,3-tetrafluoropropene (1-40 wt.%), difluoromethane (59-98 wt.%) and isobutane (1-30 wt.%); 2,3,3,3-tetrafluoropropene (1-50 wt.%), difluoromethane (1-98 wt.%) and 1,1,1-trifluoro ethane (1-98 wt.%); and 2,3,3,3-tetrafluoropropene (1-98 wt.%), difluoromethane (1-98 wt.%) and iodotrifluoromethane (1-98 wt.%). The composition is an azeotropic composition comprising: 2,3,3,3-tetrafluoropropene (1.1 wt.%), difluoromethane (92.1 wt.%) and isobutane (6.8 wt.%) at a pressure of 50.05 psi (345 kPa) and a temperature of -25 degrees C; or 2,3,3,3-tetrafluoropropene (3.9 wt.%), pentafluoroethane (74.3 wt.%) and 1,1,1-trifluoro ethane (21.8 wt.%) at a pressure of 50.02 psi (345 kPa) and a temperature of -25 degrees C. Preferred Components: The amount of 2,3,3,3-tetrafluoropropene is 1-99 wt.%. The compatibilizer comprises: (a) polyoxyalkylene glycol ether compounds of formula (R1((OR2)xOR3)y) (i), where (i) have a molecular weight of 100-300 atomic mass units; (b) amide compounds of formulae ((R1C(O)NR2R3) or (cyclo-(R4CON(R5)))) (ii), where (ii) have a molecular weight of 100-300 atomic mass units; (c) ketone compounds of formula (R1C(O)R2) (iii), where (iii) have a molecular weight of 70-300 atomic mass units; (d) nitrile compounds of formula (R1CN) (iv), where (iv) have a molecular weight of 90-200 atomic mass units; (e) chlorocarbon compounds of formula (RClx) (v), where (v) have a molecular weight of 100-200 atomic mass units; (f) aryl ether compounds of formula (R1OR2) (vi), where (vi) have a molecular weight of 100-150 atomic mass units; (g) 1,1,1-trifluoroalkane compounds of formula (CF3R1) (vii); (h) fluoroether compounds of formula (R1OCF2CF2H) (viii) or where (viii) are derived from fluoroolefin compounds and polyol compounds; (i) lactone compounds of formula (B), (C) or (D), where the molecular weight of (B), (C) or (D) is 100-300 atomic mass units; and (j) ester compounds of formula (R1CO2R2) (ix), which have a molecular weight of 80-550 atomic mass units. The fluoroolefin compounds are of formula (CF2=CXY1) (viiia). The polyol compounds are linear or branched, where the linear polyol compounds are of formula (HOCH2CRR1(CH2)z(CHOH)xCH2(CH2OH)y) (viiib) and the branched polyol compounds are of formula C(OH)t(R)u(CH2OH)v((CH2)mCH2OH)w) (viiic). The solubilizing agent comprises the compounds (a)-(i). The stabilizer is nitromethane, hindered phenols, hydroxylamines, thiols, phosphites or lactones. The tracer is 83 components e.g. hexadeuterio ethane, octadeuterio propane, difluoro dideuterio ethane, hexafluoro dideuterio propane, tetrafluoro dideuterio ethane, trifluoro trideuterio ethane, 1,1,1,2,2-pentafluoro monodeuterio propane, 1,1,1,3,3-pentafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane, monofluoropropane, 1,1,2,2,3,3,4,4,4-nonafluorobutane, 1,1,1,3,3,4,4,4-octafluorobutane, 1,1,2,2,3,3,4,4-octafluorobutane, 2,2,3,3,4,4,4-heptafluorobutane, 1,1,1,2,3,4,4,5,5,5-decafluoropentane. ethane, 1,1,1,2,3,3,3-heptafluoro monodeuterio propane, 1,1,1,2,2,3,3-heptafluo monodeuterio propane, tetrafluoro dideuterio ethane, pentafluoro trideuterio propane, trifluoro dideuteriopropane, difluoro trideuterio propane, hexafluoroethane, cyclo-hexafluoro propane, octafluoropropane, cyclo-octafluoro butane-, decafluoro butane, 1,1,1,2,3,3,3-heptafluoro-2-trifluoromethyl-propane, trifluoromethyl tetramethyl ether, trifluoromethyl pentafluoroethyl ether, trifluoromethyl tetrafluoro ethylether, trifluoroethyl difluoromethyl ether, methyl pentafluoroethyl ether, difluoroethyl trifluoromethyl ether, octafluoropropyl tetrafluoro ethyl ether, trifluoroethan, monofluoro ethane, difluoroethane, tetrafluoroethane, octafluoropropane, 1,1,1,2,2,3,3-octafluoro propane, 1,1,1,2,2,3-hexafluoropropane, 1,1,2,3,3,3-hexafluoropropane, 1,1,1,2,2,3,3,3-octafluoropropane, 1,1,1,3,3,3-hexafluoropropane, 1,1,1,3,3-pentafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2,2-pentafluoro propane, 1,1,1,2,2-pentafluoropropane, 1,1,2,2-tetrafluoropropane, 1,1,1,2-tetrafluoropropane, 1,1,1-trifluoropropane, 2,2-difluoropropane and 2-fluoropropane, 1-fluoropropane; perfluoromethylcyclopentane, perfluoromethylcyclohexane, perfluorodimethylcyclohexane (ortho, meta, or para), perfluoroethylcyclohexane, perfluoroindan, perfluorotrimethylcyclohexane or their isomers, perfluoroisopropylcyclohexane, cis-perfluorodecalin, transperfluorodecalin and cis- or trans-perfluoromethyldecalin or their isomers. In formula (i)x = 1-3;y = 1-4;R1 = H and 1-6C-aliphatic hydrocarbon radicals and y is bonding sites;R2 = 2-4C-aliphatic hydrocarbylene radicals; andR3 = H, 1-6C-aliphatic hydrocarbon radicals or 1-6C-alicyclic hydrocarbon radicals, where at least one R1 and R3 is the hydrocarbon radicals.In formula (ii)R1, R2, R3, R5 = 1-12C-aliphatic or alicyclic hydrocarbon radicals, where at most one aromatic radical have 6-12C; andR4 = 3-12C-aliphatic hydrocarbylene radicals.In formula (iii)R1, R2 = 1-12C-aliphatic, -alicyclic or -aryl hydrocarbon radicals.In formula (iv)R1 = 5-12C-aliphatic, alicyclic or aryl hydrocarbon radicals.In formula (v)x = 1 or 2; andR = 1-12C-aliphatic or alicyclic hydrocarbon radicals.In formula (vi)R1 = 6-12C-aryl hydrocarbon radicals; andR2 = 1-4C-aliphatic hydrocarbon radicals.In formula (vii)R1 = 5-15C-aliphatic or alicyclic hydrocarbon radicals.In formula (viii)R1 = 5-15C-aliphatic, alicyclic, or aromatic hydrocarbon radicals.In formula (viiia)X = H, Cl or F;Y1 = Cl, F, CF3 or ORf; andRf = CF3, C2F5 or C3F7.In formula (viiib)R, R1 = H, CH3 or C2H5;x = 0-4;y = 0-3; andz = 0 or 1In formula (viiic)R = H, CH3 or C2H5;m = 0-3;t, u = 0 or 1; andv, w = 0-4, where t+u+v+w = 4.In formula (B), (C) and (D)R1-R8 = H, linear or branched, cyclic or bicyclic, optionally saturated hydrocarbyl radicals.In formula (ix)R1, R2 = linear or cyclic, optionally saturated, alkyl or aryl radicals. EXAMPLE - Typical composition comprised of (in wt.%): difluoromethane (30); iodotrifluoromethane (10); 1,2,3,3,3-pentafluoropropene (30); and 2,3,3,3-tetrafluoropropene (30).