763 pvc thermomat a new era in the determination of the thermal stability of pvc thermal stability of pvc
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a new instrument for an approved method the pc software controls the 763 pvc thermomat and performs the evaluation a highly convenient database is available for storing sample data and results the approved method for determining the thermal stability of pvc the determination of the thermal stability of polyvinyl chloride according to din 53 381 part 1 is based on the fact that pvc decomposes at higher temperatures with the release of hcl the hydrochloric acid formed is taken up by a gas stream and absorbed in water the decomposition process is monitored by measuring the conductivity of the aqueous hcl solution the method is used for testing pvc in all stages of processing as well as for testing stabilisers both the stability time and the induction time are determined the stability time is defined as the time required to achieve a conductivity difference of 50 µs/cm the induction time is the time that elapses before the conductivity starts to rise shaply with the 763 pvc thermomat the d
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pc-controlled flexibility up to 32 samples at up to 8 different temperatures one pc can control up to four 763 pvc thermomat measuring blocks the measuring block of each 763 pvc thermomat is equipped with two heating blocks each with 4 measuring positions these heating blocks can be individually heated i.e you can measure 4 samples each at up to 8 different temperatures or of course 32 samples at the same temperature the measurements at each position can be started individually the very stable samples whose determination takes more time thus do not block the remaining measuring positions the two measuring blocks feature extraordinarily stable temperatures and excellent reproducibility this is a precondition for obtaining exact results that are comparable to measurements made in other laboratories the accessories have been revised and optimised the reaction vessels are so favourably priced that they can be regarded as being disposable the electrodes yield highly precise measuring values
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straightforward results determinations database details of the marked determination and corresponding curves measured values in green second derivative curve in blue the induction time 14.14 hours for the example shown results from the maximum of the second derivative curve the stability time is 14.32 hours i.e after this time the conductivity increase was 50 µs/cm fully automatic the computer carries out the evaluation of your pvc thermomat curves for you the evaluation algorithm determines the induction time as well as the stability time fully automatically when conductivity changes steps occur that have nothing to do with thermal decomposition the evaluation can be discontinued for a given time interval the determined results can be reprocessed in particular the induction times can be converted to different temperatures and manual evaluation each pvc thermomat curve can also be evaluated manually a pc-supported method allows to apply tangents at any point of the curve this means
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forecasts validation help determine the thermal stability at different temperatures the induction time increases by a factor of approx 2 if the temperature decreases by 10 °c this means that induction times can be converted to other temperatures of course the factor of 2 is a rough approximation the smaller the difference between the measuring temperature and the target temperature the more reliable an extrapolation to a different temperature becomes the software offers the possibility of using pvc thermomat measurements made at different temperatures for the determination of the actual temperature dependency the «extrapolation» module uses the selected determinations to calculate the change of the induction time for a temperature change of 10 °c the data can also be directly extrapolated to a particular temperature in this way it is possible to roughly estimate the stability of the product this takes place under the assumption that the temperature dependency is constant glp and more
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application example screen with curves resulting from different determinations with the 763 pvc thermomat on each curve the points corresponding to the induction and stability times are marked upside-down view of the 763 pvc thermomats conductivity measuring cell the cell is integrated into the measuring vessel lid its nominal cell constant is 1.1 cm1 6 763 pvc thermomat
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technical specifications heating blocks 2 aluminium heating blocks electrically heated can be operated at the same or at different temperatures capacity 8 samples 4 measuring positions per heating block sample size according to din 53 381 part 1 temperature control and measurement temperature range temperature correction 50 220 °c can be set in steps of 1 °c 9.9 +9.9 °c can be set in steps of 0.1 °c this correction takes into account the difference between the set sample temperature and the effective temperature of the heating block can be entered manually or automatically using the temperature sensor contained in the 6.5616.000 glp test set repeatability of the set temperature temperature difference between different measuring positions time required for heat-up from 20 °c to 120 °c to 220 °c outer housing temperature triggering temperature for safety switch-off ca 45 min temp constant to ±0.1 °c ca 60 min temp constant to ±0.1 °c <50 °c at an operating temp of 220 °c 260 °c typi
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ordering information options 2.763.0014 763 pvc thermomat 230 v 50 60 hz instrument for the fully automatic and computer-controlled determination of the thermal stability of pvc including wet-chemistry module consisting of 2 independently adjustable heating blocks each with 4 measuring positions each measuring channel can be started individually pc evaluation and control software with automatic determination of the induction time and stability time computer-supported manual evaluation using the tangent method and conversion of the results to other temperatures including standard accessories 2.763.0015 options 6.2059.000 6.2757.000 6.1816.010 6.5616.000 763 pvc thermomat 115 v 50 60 hz same as 2.763.0014 swivel base for 763 pvc thermomat exhaust collection tube for 763 pvc thermomat including 8 sealing stoppers silicone tubing i.d 6 mm o.d 9 mm 21 cm long 8 pieces are required glp test set for 763 pvc thermomat consisting of 6.1111.010 pt 100 temperature sensor 16 cm 6.1253.000 meas
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