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Page 28 of 40 

Dual Furnace Models M17705, N17706 & 17707 Iss.09 – 12/14 

 

 

Содержание M17705

Страница 1: ...9AG England Tel 44 0 1704 543830 Fax 44 0 1704 544799 Internet www isotech co uk E mail info isotech co uk The company is always willing to give technical advice and assistance where appropriate Equa...

Страница 2: ...RATION CALIBRATION APPARATUS FOR ZINC ALUMINIUM AND SILVER FIXED POINTS 18 INTRODUCTION 18 DESCRIPTION 18 METHOD OF OPERATION 18 SPECIFICATION 19 THE SODIUM HEAT PIPE FURNACE MODEL 17705 20 FINAL PART...

Страница 3: ...COVERED BY THIS GUARANTEE INTERFERENCE WITH OR FAILURE TO PROPERLY MAINTAIN THIS INSTRUMENT MAY INVALIDATE THIS GUARANTEE RECOMMENDATION The life of your ISOTECH Instrument will be prolonged if regula...

Страница 4: ...IEC 417 Caution Hot Surface ELECTRICAL SAFETY This equipment must be correctly earthed This equipment is a Class 1 Appliance A protective earth is used to ensure the conductive parts cannot become li...

Страница 5: ...is hot or cold unless wearing the appropriate protective clothing and having the necessary training 6 Do not drill modify or otherwise change the shape of the apparatus 7 Do not dismantle the apparatu...

Страница 6: ...were carried out Insulation Test M Date Earth Impedance Date Temperature cycle to maximum temperature Date Communications test if applicable Date Laboratory test at C Comments or concessions Controll...

Страница 7: ...1 Slacken the central nut using the required tube spanner the insertion of a screwdriver through the tube spanner will prevent the central stud turning 2 Remove the 3 screws securing the transit clam...

Страница 8: ...uld be replaced with a fuse A spare fuse is supplied with the furnace FUSE AND NEUTRAL LINK REPLACEMENT Hazardous voltages are exposed when the rear furnace panel is removed Before removing the panel...

Страница 9: ...0mm which can be used to pre warm or anneal up to 4 thermometers 3 A pre calibration pocket to install a single thermometer immediately prior to calibration or to house the monitor thermometer between...

Страница 10: ...range from near ambient up to 700 C MODEL 17706 Contains a potassium heat pipe with a temperature range from 400 C to 1000 C thus encompassing Zinc Aluminium and Silver freeze points Its annealing fu...

Страница 11: ...ate problem or ignored With the dual furnace thermometers can be stored pre warmed calibrated and annealed in one comprehensive facility without introducing contamination or strain The two furnaces in...

Страница 12: ...17705 N17706 17707 Iss 09 12 14 ACKNOWLEDGEMENT The Isotech dual furnace owes its origin to Dr P Marcarino of Italy His research and development solved many of the problems of contamination and handli...

Страница 13: ...this limit should be exceeded the red push button switch will reset the apparatus once the furnace temperature has fallen below the AL1 value To turn on system power at start up or as required it is n...

Страница 14: ...at up rate of the furnace is limited to ensure long life of the heat pipe Impose a heat pipe set point of 150 C and set the over temperature controller to 200 C Allow 1 to 2 hours for the furnace to s...

Страница 15: ...By adjusting the set point to a few degrees above the appropriate melting point the cell tin or indium is melted in the essentially temperature gradient free water filled heat pipe When the cell s con...

Страница 16: ...ion and give a virtually perfect freezing profile within the fixed point cell The addition of the second furnace enables thermometers to be stabilised before calibration by annealing out strain and re...

Страница 17: ...ise and then reduce the over temperature cut out setting until the relay trips thus switching off the furnace Allow the furnace to cool and isolate it from the electricity supply At the rear are two w...

Страница 18: ...appropriate melting point the cell zinc aluminium or silver is melted in an essentially temperature gradient free potassium filled heat pipe When melting is complete the heat pipe temperature is read...

Страница 19: ...mmunications RS422 Over temperature Provided on each furnace and operated by an independent sensor Protection Temperature range 400 to 1000 C Power 3kW 110V 50 60Hz Performance Essentially temperature...

Страница 20: ...ff the furnace Allow the furnace to cool and isolate it from the electricity supply At the rear are two water connections these should be connected to a controllable supply and a flow of 1 to 2 litres...

Страница 21: ...his can be accomplished by blowing air at ambient temperature across them by means of a free standing fan 1 By adjusting the set point to a few degrees above the appropriate melting point the cell alu...

Страница 22: ...422 Over temperature Provided on each furnace and operated by an independent sensor Protection Temperature range 450 to 1100 C Power 3kW 220 240V 50 60Hz 110 120V to special order Performance Essentia...

Страница 23: ...been provided in kit form that can be fitted to dual furnace Models 17705 and 17706 The completed assembly is depicted below ANNEALING COMPONENT OF THE DUAL FURNACE SHOWING AIR FLOW Air percolates thr...

Страница 24: ...ure equalising block is for use up to 700 C only Above 700 C the sensors to be calibrated may be immersed directly into the heat pipe without using an equalising block IMPORTANT NOTE Since the calibra...

Страница 25: ...t the very low incidence of failure almost implies modes not encountered previously and therefore not easy to envisage before hand Therefore we now prefer to work differently With international commun...

Страница 26: ...se A1 935 12 48 A2 Black Fuse Holder 935 11 09 45 amp Opto Relay 935 21 19 110V Contactor 935 21 18 110V Rocker Switch 935 27 02B N Thermocouple 935 14 42 White Fuse Holder 935 11 10 Inconel Cell Bask...

Страница 27: ...least 2 hours This operation outgases the basket and insulation which may smoke and discolour during this first temperature excursion The cell can then be inserted into the basket in readiness for use...

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Страница 31: ...is to contain the appropriate material in a sealed enclosure from which all other materials including air have been evacuated leaving a space to be filled by the vapour phase at a pressure appropriat...

Страница 32: ...gon In practice the difficulties of setting up conditions to facilitate this measurement can conveniently be circumvented by carrying out the alternative procedure of comparison calibration in which t...

Страница 33: ...3 ITL M 17668 ITL M 17701 3 4 7 TIN FP 231 928 505 078 3 3 2 2 ITL M 17669 ITL M 17701 3 4 7 ZINC FP 419 527 692 677 4 3 2 7 ITL M 17671 ITL M 17701 2 3 6 ALUMINIUM FP 660 323 933 473 7 0 1 6 ITL M 1...

Страница 34: ...au temperature The cell is a fragile device Although it is as rugged as is consistent with its materials and purpose it must still be regarded as a kilogram or more of mass loosely contained in a fran...

Страница 35: ...can no longer be assumed to be gas tight It may leak its enclosed gas and atmospheric air may leak into it The pressure at the freeze point may as a consequence be incorrect and more seriously contam...

Страница 36: ...However the technique requiring association of cells with other equipment involves subtlety and operator sensitivity Before relying upon measurements made in them the operator should perform enough fr...

Страница 37: ...IONAL SERVICES AND INFORMATION Isotech operates one of the world s most comprehensive UKAS supervised Laboratories Training is available to customers at an agreed daily rate The Isothermal Journal of...

Страница 38: ...Page 38 of 40 Dual Furnace Models M17705 N17706 17707 Iss 09 12 14 FIGURE 1 SECTION THROUGH DUAL FURNACE...

Страница 39: ...ss 09 12 14 FIGURE 2 SEALED METAL FREEZING POINT CELL A High purity graphite crucible and cover B High purity graphite sleeve C High purity metal D Fused quartz envelope filled to give a pressure of 1...

Страница 40: ...Page 40 of 40 Dual Furnace Models M17705 N17706 17707 Iss 09 12 14 FIGURE 3 SEALED METAL FREEZING POINT CELL BODY DIMENSIONS...

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