1. Ref: 2500sell.ppt (19/08/2015) 1 EUROTHERM CONTROLS Furnace Atmosphere Control What is it? Used to case harden steel Function of Temperature & Carbon Potential Requires sychronised programming of both parameters Who uses it? Furnace OEM’s Specialist heat treaters Various industries including Automotive Aerospace Shipbuilding Toolmaking

2. Ref: 2500sell.ppt (19/08/2015) 2 EUROTHERM CONTROLS 26/2704 Zirconia Controller Ideal For: Temperature profiling Carbon potential Furnace dewpoint ReDox atmosphere Combustion control Used in: Carburising furnaces Endothermic generators Ceramic kilns Glass furnaces Boiler plants

3. Ref: 2500sell.ppt (19/08/2015) 3 EUROTHERM CONTROLS Zirconia Probe Air from inside furnace Air from inside furnace Self clean port Furnace wall Air from outside furnace Thermocouple Electrode and thermocouple connections Inner electrode Zirconia cell Outer electrode Zirconia Probe Assembly E=0.0215*T*Ln(0.2095/pO2 E= Probe EMF(mV) T= Probe Temperature(Kelvin) pO2= Partial pressure of oxygen in the furnace 0.2095= 20.95%(Partial pressure of oxygen in reference air

4. Ref: 2500sell.ppt (19/08/2015) 4 EUROTHERM CONTROLS Zirconia Function Block Most Probes Supported »Drayton, SSI, Marathon, AACC, Bosch, etc »%Carbon, Oxygen(log or PPM), Dewpoint »Automatic gas reference compensation Probe Clean Output »Manual or Automatic Sooting Alarm Probe Health Alarm Zirconia Block Zirconia Probe Temperature Probe mV PV Output Gas Reference Probe Clean Demand Sooting Alarm Probe Alarm Probe Clean

5. Ref: 2500sell.ppt (19/08/2015) 5 EUROTHERM CONTROLS Furnace Atmosphere Control Thermocouple Probe Clean Thermocouple Temperature Control Loop Heating Cooling Setpoint Programmer Carbon Control Loop Enrichment Gas Dilution Air Zirconia Function Block C mV Gas Reference Probe mV Gas Ref Probe Health Sooting Alarm Probe Clean Temp SP %Carbon SP Program Events Run Hold Reset Thermocouple C %C Quench Control Loop Heating C Quench SP