natgillin/translations-raw huggingface dataset:
The temperature at the dividing line is read by adjusting the pointer to rest at the line.
Temperatura na razmejitveni črti se odčita tako, da se nanjo naravna kazalec.
Melt microscope
Talilni mikroskop
Several microscope hot stages are in use for the determination of melting temperatures with very small quantities of material.
Za določanje tališča z zelo majhnimi količinami materiala se uporablja več mikroskopskih grelnih mizic.
In most of the hot stages the temperature is measured with a sensitive thermocouple but sometimes mercury thermometers are used.
Pri večini grelnih mizic se temperatura meri z občutljivim termočlenom, vendar se včasih uporablja tudi živosrebrni termometer.
A typical microscope hot stage melting temperature apparatus has a heating chamber which contains a metal plate upon which the sample is placed on a slide.
Značilna mikroskopska aparatura z ogrevalnimi mizicami za določanje tališča ima grelno komoro, ki vsebuje kovinsko ploščo, na katero položimo vzorec na objektnem stekelcu.
The centre of the metal plate contains a hole permitting the entrance of light from the illuminating mirror of the microscope.
Na sredini kovinske plošče je luknjica, ki omogoča vstop svetlobe s kolektorja mikroskopa.
When in use, the chamber is closed by a glass plate to exclude air from the sample area.
Med uporabo je komora zaprta s stekleno ploščo, ki preprečuje vdor zraka v območje vzorca.
The heating of the sample is regulated by a rheostat.
Segrevanje vzorca se uravnava z reostatom.
For very precise measurements on optically anisotropic substances, polarised light may be used.
Za zelo natančne meritve pri optično anizotropnih snoveh se lahko uporabi polarizirana svetloba.
Meniscus method
Metoda z meniskusom
This method is specifically used for polyamides.
Ta metoda se uporablja posebej za poliamide.
The temperature at which the displacement of a meniscus of silicone oil, enclosed between a hot stage and a cover-glass supported by the polyamide test specimen, is determined visually.
Vizualno se določi temperatura, pri kateri se premakne meniskus silikonskega olja, ki je med ogrevalno mizico in krovnim stekelcem na preskusnem vzorcu poliamida.
Method to determine the freezing temperature
Metoda za določanje zmrzišča
The sample is placed in a special test tube and placed in an apparatus for the determination of the freezing temperature.
Vzorec se da v posebno epruveto, ta pa v aparaturo za določanje zmrzišča.
The sample is stirred gently and continuously during cooling and the temperature is measured at suitable intervals.
Vzorec se ohlaja in ves čas rahlo meša in v primernih intervalih se meri temperatura.
As soon as the temperature remains constant for a few readings this temperature (corrected for thermometer error) is recorded as the freezing temperature.
Ko je temperatura pri nekaj zaporednih odčitkih nespremenjena, se ta temperatura (popravljena z upoštevanjem napake termometra) zapiše kot zmrzišče.
Supercooling must be avoided by maintaining equilibrium between the solid and the liquid phases.
Treba je preprečiti podhladitev, in sicer tako da se vzdržuje ravnotežje med trdno in tekočo fazo.
Thermal analysis
Termična analiza
Differential thermal analysis (DTA)
Diferenčna termična analiza (DTA)
This technique records the difference in temperatures between the substance and a reference material as a function of temperature, while the substance and reference material are subjected to the same controlled temperature programme.
Pri tej tehniki se beleži razlika v temperaturi snovi in referenčnega materiala v odvisnosti od temperature, pri čemer se na snovi in na referenčnem materialu izvaja isti nadzorovani temperaturni program.
When the sample undergoes a transition involving a change of enthalpy, that change is indicated by an endothermic (melting) or exothermic (freezing) departure from the base line of the temperature record.
Ko gre vzorec skozi fazni prehod, ki vključuje spremembo entalpije, se ta sprememba pokaže kot endotermni (tališče) ali eksotermni (zmrzišče) odmik od bazne črte zapisa temperature.
Differential scanning calorimetry (DSC)
Diferenčna dinamična kalorimetrija (DSC)
This technique records the difference in energy inputs into a substance and a reference material, as a function of temperature, while the substance and reference material are subjected to the same controlled temperature programme.
Pri tej tehniki se beleži razlika v vnosu energije v snov in referenčni material v odvisnosti od temperature, pri čemer se na snovi in referenčnem materialu izvaja isti nadzorovani temperaturni program.
This energy is the energy necessary to establish zero temperature difference between the substance and the reference material.
Ta energija je energija, potrebna za izenačitev temperature snovi in referenčnega materiala.
When the sample undergoes a transition involving a change of enthalpy, that change is indicated by an endothermic (melting) or exothermic (freezing) departure from the base line of the heat flow record.
Ko gre vzorec skozi fazni prehod, ki vključuje spremembo entalpije, se ta sprememba pokaže kot endotermni (tališče) ali eksotermni (zmrzišče) odmik od bazne črte zapisa toplotnega pretoka.
Pour point
Točka tečenja
This method was developed for use with petroleum oils and is suitable for use with oily substances with low melting temperatures.
Ta metoda je bila razvita za nafto in je primerna za oljaste snovi z nizkim tališčem.
After preliminary heating, the sample is cooled at a specific rate and examined at intervals of 3 K for flow characteristics.
Po predhodnem segrevanju se vzorec ohlaja s točno določeno hitrostjo in v intervalih 3 K se opazujejo značilnosti tečenja.
The lowest temperature at which movement of the substance is observed is recorded as the pour point.
Najnižja temperatura, pri kateri se še opazi premikanje snovi, se zapiše kot točka tečenja.
QUALITY CRITERIA
MERILA KAKOVOSTI
The applicability and accuracy of the different methods used for the determination of the melting temperature/melting range are listed in the following table:
Uporabnost in točnost različnih metod, ki se uporabljajo za določanje tališča/talilnega območja, sta navedeni v naslednji tabeli:
TABLE: APPLICABILITY OF THE METHODS
TABELA: UPORABNOST METOD
Capillary methods
Kapilarne metode
Method of measurement
Merilna metoda
Substances which can be pulverised
Snovi, ki jih je mogoče uprašiti
Substances which are not readily pulverised
Snovi, ki jih ni mogoče zlahka uprašiti
Temperature range
Temperaturno območje
Estimated accuracy [1]
Ocenjena točnost [1]
Existing standards
Veljavni standard
only to a few
le za nekatere
273 to 573 K
273 do 573 K
Melting temperature with metal block
Naprave za merjenje tališča s kovinskim blokom
293 to >573 K
293 do > 573 K
several with appliance devices
za številne z uporabo prilagoditvenih naprav
253 to 573 K
253 do 573 K
Hot stages and freezing methods
Metode z ogrevalnimi mizicami in metode za določanje zmrzišča
Estimated accuracy [2]
Ocenjena točnost [2]
283 to > 573 K
283 do > 573 K
273 to > 573 K
273 do > 573 K
specifically for polyamides
posebej za poliamide
293 to > 573 K
293 do > 573 K
Freezing temperature
Metode za določanje zmrzišča
223 to 573 K
223 do 573 K
e.g. BS 4695
npr. BS 4695
Estimated accuracy [3]
Ocenjena točnost [3]
Differential thermal analysis
Diferenčna termična analiza
173 to 1273 K
173 do 1273 K
up to 600 K ±0,5 K up to 1273 K ±2,0 K
Do 600 K ±0,5 K do 1273 K ±2,0 K
Differential scanning calorimetry
Diferenčna dinamična kalorimetrija
Estimated accuracy [4]
Ocenjena točnost [4]
for petroleum oils and oily substances
za nafto in oljaste snovi
223 to 323 K
223 do 323 K
DESCRIPTION OF THE METHODS
OPIS METOD
The procedures of nearly all the test methods have been described in international and national standards (see Appendix 1).
Postopki skoraj vseh preskusnih metod so opisani v mednarodnih in nacionalnih standardih (glej dodatek 1).
Methods with capillary tube
Metode s kapilarno cevko
When subjected to a slow temperature rise, finely pulverised substances usually show the stages of melting shown in figure 1.
Kadar se drobno uprašene snovi počasi segrevajo, se običajno pokažejo talilne faze s slike 1.
Stage A
Faza A
Stage B
Faza B
Stage C
Faza C
Stage D
Faza D
Stage E
Faza E
(beginning of melting): fine droplets adhere uniformly to the inside wall of the capillary tube
(začetek taljenja): drobne kapljice se enakomerno oprimejo notranje stene kapilarne cevke
a clearance appears between the sample and the inside wall due to shrinkage of the melt
med vzorcem in notranjo steno se zaradi krčenja taline pojavi praznina
the shrunken sample begins to collapse downwards and liquefies
skrčen vzorec se začne sesedati in utekočinjati
a complete meniscus is formed at the surface but an appreciate amount of the sample remains solid
na površini se oblikuje popoln meniskus, vendar znatna količina vzorca ostane trdna
(final stage melting): there are no solid particles
(zadnja faza taljenja): ni več nobenih trdnih delcev
During the determination of the melting temperature, the temperatures are recorded at the beginning of the melting and at the final stage.
Pri določanju tališča zapišemo temperaturi na začetku taljenja in v zadnji fazi.
Melting temperature devices with liquid bath apparatus
Naprave za merjenje tališča s tekočinsko kopeljo
Figure 2 shows a type of standardised melting temperature apparatus made of glass (JIS K 0064); all specifications are in millimeters.
Slika 2 prikazuje vrsto standardizirane steklene aparature za merjenje tališča (JIS K 0064); vse specifikacije so v milimetrih.
Figure 2
Silka 2
Measurement vessel
Merilna posoda
Stopper
B: Zamašek
Vent
C: Odprtina za zrak
Thermometer
D: Termometer
Auxiliary thermometer
E: Pomožni termometer
Bath liquid
F: Tekočina za kopel
Capillary tube made of glass, 80 to 100 mm in length, 1,0 ± 0,2 mm inner diameter, 0,2 to 0,3 mm wall thickness
G: Steklena kapilarna cevka, dolga 80 do 100 mm, z notranjim premerom 1,0 ± 0,2 mm in steno, debelo 0,2 do 0,3 mm
Side tube
H: Stranska cevka
Bath liquid:
Tekočina za kopel:
A suitable liquid should be chosen.
Izbrati je treba primerno tekočino.
The choice of the liquid depends upon the melting temperature to be determined, e.g. liquid paraffin for melting temperatures no higher than 473 K, silicone oil for melting temperatures no higher than 573 K.
Izbira tekočine je odvisna od tališča, ki se določa, npr. tekoči parafin za tališča do največ 473 K, silikonsko olje za tališča do največ 573 K.
For melting temperatures above 523 K, a mixture consisting of three parts sulphuric acid and two parts potassium sulphate (in mass ratio) can be used.
Za tališča, višja od 523 K, se lahko uporabi zmes treh delov žveplove kisline in dveh delov kalijevega sulfata (v masnem razmerju).
Suitable precautions should be taken if a mixture such as this is used.
Pri uporabi take zmesi je treba upoštevati primerne varnostne ukrepe.
Thermometer:
Termometer:
Only those thermometers should be used which fulfil the requirements of the following or equivalent standards:
Uporabljajo se lahko samo termometri, ki izpolnjujejo zahteve naslednjih ali njim enakovrednih standardov:
Procedure:
Postopek:
The dry substance is finely pulverised in a mortar and is put into the capillary tube, fused at one end, so that the filling level is approximately 3 mm after being tightly packed.
Suha snov se na drobno upraši v terilnici in da v na enem koncu zataljeno kapilaro, tako da je tesno natlačene snovi v kapilari približno 3 mm.
To obtain a uniform packed sample, the capillary tube should be dropped from a height of approximately 700 mm through a glass tube vertically onto a watch glass.
Da bo vzorec enakomerno potlačen, je treba kapilaro z višine približno 700 mm spustiti skozi stekleno cevko navpično na urno steklo.
The filled capillary tube is placed in the bath so that the middle part of the mercury bulb of the thermometer touches the capillary tube at the part where the sample is located.
Napolnjena kapilarna cevka se postavi v kopel, tako da se srednji del bučke termometra z živim srebrom dotika kapilarne cevke na delu, kjer je vzorec.
Usually the capillary tube is introduced into the apparatus about 10 K below the melting temperature.
Običajno se kapilarna cevka vstavi v aparaturo pri temperaturi približno 10 K pod tališčem.
The bath liquid is heated so that the temperature rise is approximately 3 K/min.
Tekočina kopeli se segreva tako, da temperatura narašča približno za 3 K/min.
The liquid should be stirred.
Tekočino je treba mešati.
At about 10 K below the expected melting temperature the rate of temperature rise is adjusted to a maximum of 1 K/min.
Pri približno 10 K pod pričakovanim tališčem se naraščanje temperature naravna na največ 1 K/min.
The calculation of the melting temperature is as follows:
Tališče izračunamo na naslednji način:
T = TD + 0,00016 (TD - TE) n
T = TD+0,00016 (TD - TĚ) n
T corrected melting temperature in K
T popravljeno tališče v K
temperature reading of thermometer D in K
odčitana temperatura na termometru D v K
temperature reading of thermometer E in K
odčitana temperatura na termometru E v K
n number of graduations of mercury thread on thermometer D at emergent stem.
n število graduacij živosrebrnega stolpca na termometru D na delu, ki gleda iz tekočine.
Apparatus:
Aparatura:
This consists of:
Sestavljajo jo:
a cylindrical metal block, the upper part of which is hollow and forms a chamber (see figure 3),
valjast kovinski blok, katerega zgornji del je votel in predstavlja komoro (glej sliko 3),
a metal plug, with two or more holes, allowing tubes to be mounted into the metal block,
kovinski zamašek z dvema ali več luknjami, ki omogočajo vstavljanje cevk v kovinski blok,
a heating system, for the metal block, provided for example by an electrical resistance enclosed in the block,
grelni sistem za kovinski blok, na primer z električnim uporom, vgrajenim v blok,
a rheostat for regulation of power input, if electric heating is used,
reostat za uravnavanje dovoda energije, če se uporabi električno gretje,
four windows of heat-resistant glass on the lateral walls of the chamber, diametrically disposed at right-angles to each other.
štiri okenca iz stekla, odpornega proti vročini, v stranskih stenah komore, diametralno razporejenih pravokotno drug na drugega.
In front of one of these windows is mounted an eye-piece for observing the capillary tube.
Pred enim od okenc je postavljen okular za opazovanje kapilarne cevke.
The other three windows are used for illuminating the inside of the enclosure by means of lamps,
Ostala tri okenca se uporabljajo za osvetljevanje notranjosti komore z žarnicami,
See standards mentioned in 1.6.1.1.
Glej standarde, navedene v 1.6.1.1.
Thermoelectrical measuring devices with comparable accuracy are also applicable.
Lahko se uporabijo tudi termoelektrični instrumenti s primerljivo točnostjo.
Capillary tube
Kapilarna cevka
Metal plug
Kovinski zamašek
Eye-piece
Okular
Lamp
Žarnica
Electrical resistance
Električni upor
Metal heating block
Kovinski ogrevalni blok
Apparatus and procedure:
Aparatura in postopek:
The apparatus consists of a metal chamber with automated heating system.
Aparaturo sestavlja kovinska komora z avtomatiziranim grelnim sistemom.
Three capillary are filled accordingly to 1.6.1.1 and placed in the oven.
Tri kapilarne cevke se napolnijo v skladu z 1.6.1.1 in postavijo v grelno komoro.
Several linear increases of temperature are available for calibrating the apparatus and the suitable temperature rise is electrically adjusted at a pre-selected constant and linear rate. recorders show the actual oven temperature and the temperature of the substance in the capillary tubes.
Za umerjanje aparature je na voljo več linearnih naraščanj temperature in primerno naraščanje temperature se električno naravna na vnaprej določeno konstantno in linearno hitrost naraščanja. Zapisovalniki kažejo dejansko temperaturo grelne komore in temperaturo snovi v kapilarnih cevkah.
See Appendix.
Glej dodatek.
Meniscus method (polyamides)
Metoda z meniskusom (poliamidi)
The heating rate through the melting temperature should be less than 1 K/min.
Hitrost segrevanja v območju tališča mora biti manjša od 1 K/min.
Methods for the determination of the freezing temperature
Metode za določanje zmrzišča
Determination of the pour point
Določanje točke tečenja
A thermometer correction is necessary in some cases.
V nekaterih primerih je potreben popravek termometra.
The test report shall, if possible, include the following information:
V poročilo o preskusu se, če je možno, vključijo naslednje informacije:
method used,
uporabljena metoda,
precise specification of the substance (identity and impurities) and preliminary purification step, if any,
natančna specifikacija snovi (identiteta in nečistote) in predhodno prečiščevanje, če je bilo opravljeno,
an estimate of the accuracy.
ocena točnosti.
The mean of at least two measurements which are in the range of the estimated accuracy (see tables) is reported as the melting temperature.
Kot tališče se navede srednja vrednost najmanj dveh meritev, ki sta v območju predvidene točnosti (glej tabele).
If the difference between the temperature at the beginning and at the final stage of melting is within the limits of the accuracy of the method, the temperature at the final stage of melting is taken as the melting temperature; otherwise the two temperatures are reported.
Če je razlika med temperaturo na začetku taljenja in tisto v zadnji fazi taljenja znotraj meja točnosti metode, se kot tališče navede temperatura v zadnji fazi taljenja; sicer pa se navedeta obe temperaturi.
If the substance decomposes or sublimes before the melting temperature is reached, the temperature at which the effect is observed shall be reported.
Če snov razpade ali sublimira, preden se doseže tališče, se navede temperatura, pri kateri so bile opažene te spremembe.
All information and remarks relevant for the interpretation of results have to be reported, especially with regard to impurities and physical state of the substance.
Navesti je treba vse informacije in opombe, pomembne za razlago rezultatov, zlasti glede nečistot in agregatnega stanja snovi.
Experimental thermodynamics, Butterworths, London 1975, vol. II, p. 803-834.
Experimental thermodynamics, Butterworths, London 1975, vol. II, str. 803–834.
Weissberger ed.: Technique of organic Chemistry, Physical Methods of Organic Chemistry, 3rd ed., Interscience Publ., New York, 1959, vol. I, Part I, Chapter VII.
Weissberger éd.: Technique of organic Chemistry, Physical Methods of Organic Chemistry, 3rd éd., Interscience Publ., New York, 1959, vol. I, Part I, Chapter VII.
IUPAC, Physicochemical measurements: Catalogue of reference materials from national laboratories, Pure and applied chemistry, 1976, vol. 48, p. 505-515.
IUPAC, Physicochemical measurements: Catalogue of reference materials from national laboratories, Pure and applied chemistry, 1976, vol. 48, str. 505–515.
Appendix
DODATEK
For additional technical details, the following standards may be consulted for example.
Glede dodatnih tehničnih podrobnosti so lahko v pomoč na primer naslednji standardi:
Plastics — polyamides — determination of ‘melting point’
Plastics – polyamides – determination of „melting point“
Détermination du ‘point de fusion’ méthode du ménisque
Détermination du „point de fusion“ méthode du ménisque
The methods and devices described here can be applied to liquid and low melting substances, provided that these do not undergo chemical reaction below the boiling temperature (for example: auto-oxidation, rearrangement, degradation, etc.).
Tukaj opisane metode in naprave se lahko uporabljajo za tekoče snovi in snovi z nizkim tališčem, pod pogojem da pri njih ne pride do kemične reakcije pri temperaturah pod vreliščem (na primer avtooksidacije, prerazporeditve, razgradnje itd.).
The methods can be applied to pure and to impure liquid substances.
Te metode se lahko uporabljajo za čiste in nečiste tekoče snovi.
Emphasis is put on the methods using photocell detection and thermal analysis, because these methods allow the determination of melting as well as boiling temperatures.
Poudarjene so metode s fotocelično detekcijo in termično analizo, ker te metode omogočajo določanje tališča in vrelišča.
Moreover, measurements can be performed automatically.
Poleg tega je meritve mogoče opraviti avtomatsko.
The ‘dynamic method’ has the advantage that it can also be applied to the determination of the vapour pressure and it is not necessary to correct the boiling temperature to the normal pressure (101,325 kPa) because the normal pressure can be adjusted during the measurement by a manostat.
„Dinamična metoda“ ima to prednost, da se lahko uporabi tudi za določanje parnega tlaka ter da ni treba popravljati vrelišča glede na normalni tlak (101,325 kPa), ker se med merjenjem z manostatom lahko naravna normalni tlak.
The influence of impurities on the determination of the boiling temperature depends greatly upon the nature of the impurity.
Vpliv nečistot na določanje vrelišča je v veliki meri odvisen od narave nečistote.
When there are volatile impurities in the sample, which could affect the results, the substance may be purified.
Kadar so v vzorcu hlapne nečistote, ki bi lahko vplivale na rezultat, se snov lahko prečisti.
The normal boiling temperature is defined as the temperature at which the vapour pressure of a liquid is 101,325 kPa.
Normalno vrelišče je opredeljeno kot temperatura, pri kateri je parni tlak tekočine enak 101,325 kPa.
If the boiling temperature is not measured at normal atmospheric pressure, the temperature dependence of the vapour pressure can be described by the Clausius-Clapeyron equation:
Če se vrelišče ne meri pri normalnem atmosferskem tlaku, lahko odvisnost parnega tlaka od temperature opisemo s Clausius-Clapeyronovo enačbo:
+const.
+konst.
p the vapour pressure of the substance in pascals
p parni tlak snovi v paskalih
Δ H v
AH V
its heat of vaporisation in J mol-1
izparilna toplota v J mol-1
R the universal molar gas constant = 8,314 J mol-1 K-1
R splošna plinska konstanta = 8,314 J mol-1 K-1
T thermodynamic temperature in K
T termodinamična temperatura v K
The boiling temperature is stated with regard to the ambient pressure during the measurement.
Vrelišče se navede glede na zračni tlak med meritvijo.
Conversions
Pretvorbe
Pressure (units: kPa)
Tlak (enote: kPa)
(‘bar’ is still permissible but not recommended)
(enota „bar“ je še vedno dovoljena, vendar se ne priporoča)
(the units ‘mm Hg’ and ‘Torr’ are not permitted)
(enoti „mm Hg“ in „tor“ nista dovoljeni)
1 atm standard atmosphere = 101325 Pa
1 atm standardna atmosfera = 101325 Pa
(the unit ‘atm’ is not permitted)
(enota „atm“ ni dovoljena).
Temperature (units: K)
Temperatura (enote: K)
Some calibration substances can be found in the methods listed in the Appendix.
Nekatere snovi za umerjanje so naštete v metodah, navedenih v dodatku.
Five methods for the determination of the boiling temperature (boiling range) are based on the measurement of the boiling temperature, two others are based on thermal analysis.
Pet metod za določanje vrelišča (vreliščnega območja) temelji na merjenju vrelišča, dve pa temeljita na termični analizi.
Determination by use of the ebulliometer
Določanje z uporabo ebulioskopa
Ebulliometers were originally developed for the determination of the molecular weight by boiling temperature elevation, but they are also suited for exact boiling temperature measurements.
Ebulioskopi so bili prvotno zasnovani za določanje molekulske mase glede na naraščajoče vrelišče, vendar so primerni tudi za natančno merjenje vrelišča.
A very simple apparatus is described in ASTM D 1120-72 (see Appendix).
Zelo preprosta aparatura je opisana v ASTM D 1120-72 (glej Dodatek).
The liquid is heated in this apparatus under equilibrium conditions at atmospheric pressure until it is boiling.
Tekočina se segrejeva v tej aparaturi v ravnotežnih pogojih pri atmosferskem tlaku, dokler ne zavre.
Dynamic method
Dinamična metoda
This method involves the measurement of the vapour recondensation temperature by means of an appropriate thermometer in the reflux while boiling.
Ta metoda vključuje merjenje temperature rekondenzacije pare z ustreznim termometrom v povratnem toku med vretjem.
The pressure can be varied in this method.
Tlak se pri tej metodi lahko spreminja.