XMTC Thermal Conductivity Transmitter - Thermo Fisher

GESensing & Inspection TechnologiesXMTCPanametrics Thermal ConductivityBinary Gas TransmitterApplicationsA thermal conductivity gas transmitter for use in thefollowing industries and applications:Metals IndustryH 2 in N 2 ; atmosphere in metal heat-treatingfurnacesElectric Power IndustryH 2 in cooling systems for generatorsPetroleum IndustryH 2 in hydrocarbon streamsChemical Industry• H 2 in ammonia synthesis gas• H 2 in methanol synthesis gas• H 2 in chlorine plantsMethane Industry• CO 2 in methaneLandfill/Biogas Industry• CO 2 in biogas• CH 4 in biogasGas Production IndustryPurity monitoring of argon, hydrogen, nitrogen andheliumFood IndustryCO 2 in fermentation processesFeatures• Ultra-stable glass-coated thermistors• Single or dual gas push-button calibration• PC interface package for digital output• Type 4X/7 construction; ATEX, FM and CSA certifiedfor Class I, Division 1 hazardous areasg

The microprocessor-based XMTC is a compact, rugged,online thermal conductivity transmitter that measuresthe concentration of binary gas mixtures containinghydrogen, carbon dioxide, methane or helium. Theanalyzer also combines computer enhanced signalmeasurement with fast-response software, real-timeerror detection and digital communication via an RS232or RS485 interface.Theory of OperationTwo ultrastable, precision glass-coated thermistorsare used—one in contact with the sample gas and theother in contact with the reference gas (such as airin a sealed chamber). The thermistors are mountedso that they are in close proximity to the stainlesssteel (or Hastelloy ® ) walls of the sample chamber. Theentire transmitter is temperature-controlled, and thethermistors are heated to an elevated temperature in aconstant-current Wheatstone bridge. The thermistorslose heat to the walls of the sample chamber at a ratethat is proportional to the thermal conductivity of thegas surrounding them. Thus, each thermistor will reacha different equilibrium temperature. The temperaturedifference between the two thermistors is detectedin the Wheatstone bridge, and the resulting bridgevoltage is amplified and converted to a linear 4 to 20 mAoutput proportional to the concentration of one of theconstituents of the binary or pseudo binary gas mixture.Minimal Calibration and ServiceThe XMTC is the most stable thermal conductivityanalyzer on the market today. The rugged XMTCmeasuring cell resists contamination and remainsinsensitive to flow variations. Since the design usesno moving parts, the transmitter can easily withstandthe shock, vibration and harsh environment found inmany industrial applications. If the transmitter requiresmaintenance, its modular construction permits fast andeasy servicing. Users can field-calibrate it quickly andreplace the plug-in measuring cell with a precalibratedspare in minutes.GE offers sample systems for a wide variety ofapplications. For assistance in designing your ownsample system, please consult the factory.Relative Thermal Conductivities ofCommon GasesAir/N 2CO 2SO 2CH 4 NeHe H 2Cl 2 ARC 2 – C 6212°F (100°C) is relative thermal conductivity at 212°F (100°C)Gas Formula Chemical Gas Formula ChemicalAcetylene 0.90 C 2 H 2 Helium 5.53 HeAir 1.00 N 2 /O 2 n-Heptane 0.58 C 7 H 16Argon 0.67 Ar n-Hexane 0.66 C 6 H 14n-Butane 0.74 C 4 H 10 Hydrogen 6.80 H 2Carbon Dioxide 0.70 CO 2 Methane 1.45 CH 4Chlorine 0.34 Cl 2 Methyl Chloride 0.53 CH 3 ClEthylene Alcohol 0.64 C 2 H 5 OH 4 Neon 1.84 NeEthylene 0.98 C 2 H 4 n-Pentane 0.70 C 5 H 12Ethylene Oxide 0.62 C 2 H 4 O Sulfur Dioxide 0.38 SO 2Freon-11 0.37 CCI 3 F Water Vapor 0.77 H 2 OChoosing the Reference GasThe simple two-port version can be selected formeasurement of zero-based gas mixtures using thesealed reference gas (air) or the four-port version(generally preferred for zero-suppressed gas mixtures)where higher accuracy is obtained using a specificflowing reference gas.Sample SystemA sample system is mandatory for use with the XMTC.The design of the sample system will depend on theconditions of the sample gas and the requirementsof the application. In general, a sample system mustdeliver a clean, representative sample to the XMTC ata temperature, pressure and flow rate that are withinacceptable limits. Standard XMTC sample conditionsare: a temperature of less than 122°F (50°C) for a celloperating temperature of 131°F (55°C) with a flow rate of0.5 SCFH (250 cc/min) at atmospheric pressure. Highertemperature and pressure options are available.

XMTC SpecificationsPerformanceAccuracy±2% of spanLinearity±1% of spanRepeatability±0.5% of spanZero Stability±0.5% of span per weekSpan Stability±0.5% of span per weekResponse Time20 seconds for 90% of step changeMeasurement Ranges• 0% to 2%• 0% to 5%• 0% to 10%• 0% to 25%• 0% to 50%• 0% to 100%• 50% to 100%• 80% to 100%• 90% to 100%• 95% to 100%• 98% to 100%9.54 in*(242.3 mm)10.48 in*(266.2 mm)2.76 in(70 mm)4.13 in*(105 mm)5.07 in**(129 mm)Required Flow Rate for Optional Reference Gas0.01 to 4.0 SCFH (5 to 2,000 cc/min);0.5 SCFH (250 cc/min) nominalFunctionalAnalog Output4 to 20 mA isolated, 800 Ω maximum field-programmablePower24 VDC ±2 VDC, 1.2 A maximumTemperature• Standard:• Optional:6.10 in(155 mm)5.71 in(145 mm)XMTCTransmitter1.16 in(29.5 mm)3.27 in(83 mm)4.46 in(113.3 mm)0.59 in(15 mm)131°F (55°C)149°F (65°C)3/4 inNPTFemale8.66 in(220 mm)Optional flamearrestors forexplosion-proofunits only1/4 inNPTFemale0.39 in(10 mm)diameterXMTC thermal conductivity transmitter dimensions6.10 in(155 mm)24 VDC/1 AmpReturn4 t0 20 mA4 t0 20 mARed_RXWhite_TXGround12+3-41230.47 in(11.9 mm)*Weatherproof**Explosion-proofMeasurement Gases (Typical)• H 2 in N 2 , air or CO 2• He in N 2 or air• CO 2 in N 2 or air• SO 2 in air• Argon in N 2 or air• H 2 /CO 2 /Air for hydrogen-cooled generatorsAmbient Temperature Effect±0.09% of span per °F±0.05% of span per °CRequired Sample Flow Rate0.1 to 4.0 SCFH (10 to 2,000 cc/min);0.5 SCFH (250 cc/min) nominal

XMTC SpecificationsPhysicalSensor Wetted Materials• Standard:316 stainless steel, glass and Viton ® O-rings• Optional:Hastelloy C276, titanium and Chemraz ® O-ringsDimensions• Weatherproof unit (h x diameter):9.53 in x 5.71 in (242 mm x 145 mm)• Explosion-proof unit (h x diameter):10.47 in x 5.7 in (266 mm x 145 mm)Weight9.5 lb (4.3 kg)Connections• 3/4 in NPTF (electrical conduit)• 1/4 in NPTF (sample inlet/outlet and optional referenceinlet/outlet)Environmental• Weatherproof: Type 4X/IP66• Explosion-proof: Class I, Division 1, Groups A,B,C&DFM File No. J.I.2Z4A8.AE (3615) CSA LR44204-15• Flameproof: II 2 GD EEx d IIC T6 or T5ISSeP02ATEX022European ComplianceComplies with EMC Directive 2004/108/ECand PED 97/23/ECOrder and Calibration InformationXMTC Thermal Conductivity TransmitterMeasuring Cell Package3 Weatherproof, four-port, flowing reference gas, CPVC cell4 Explosion-proof enclosure, four-port, flowing reference gas,CPVC cell5 Weatherproof enclosure, two-port, sealed reference gas,FEP-coated aluminum cell6 Explosion-proof, two-port, sealed reference gas, FEP-coatedaluminum cellW No enclosure, two-port, sealed reference gas, FEP-coatedaluminum cell (spare)Y No enclosure, two-port, flowing reference gas, CPVC cell (spare)CE Compliance2 4 to 20 mAC CE CompliantCalibration Label for Explosion-proof Options1 T6 Rating for Ambient Temperatures Up to 55°C2 T5 Rating for Ambient Temperatures Up to 65°CMaterials1 316 stainless steel2 Hastelloy C276XMTC – ___ ___ ___ ___ Use this number to order productFor explosion-proof/flameproof packages, select temperature as follows: 131°F (55°C) for EEX dIIC T6 or 149°F (65°C) for EEx d IIC T5. For weatherproof packages, select temperature as follows:149°F (65°C).XMTC Calibration SpecificationsCell Range2 0% to 2% 8 0% to 100%3 0% to 5% A 90% to 100%4 0% to 10% B 80% to 100%6 0% to 25% C 50% to 100%7 0% to 50% D 98% to 100%E 95% to 100%S SpecialCalibration Gases1 H 2 in N 22 CO 2 in N 2 (minimum range 0% to 20% CO 2 )3 CO 2 in air (minimum range 0% to 20% CO 2 )4 He in N 25 He in air6 Calibration for hydrogen-cooled generators, H 2 /CO 2 /air7 CH 4 in CO 2 (min range 0% to 10% CH 4 )S Other, please specifyTemperature Control Set Point1 131°F (55°C), suitable for ambient temperatures upto 122°F (50°C)2 158°F (70°C), suitable for ambient temperatures upto 149°F (65°C)S SpecialXMTC-Cal ___ ___ ___ Use this number to order productBinary or pseudobinary gas composition must total 100%gwww.gesensinginspection.com920-037G© 2009 General Electric Company. All Rights Reserved. Specifications are subject to change without notice. GE is a registered trademark of General Electric Company. Other company or productnames mentioned in this document may be trademarks or registered trademarks of their respective companies, which are not affiliated with GE.