natgillin/translations-raw huggingface dataset:
The quantity of substance leaving a cell per unit time through an aperture of known size is determined under vacuum conditions such that return of substance into the cell is negligible (e.g. by measurement of the pulse generated on a sensitive balance by a vapour jet or by measuring the weight loss).
Določi se količina snovi, ki zapusti merilno celico v časovni enoti skozi odprtino znane velikosti, v takih vakuumskih pogojih, da je količina v celico vrnjene snovi zanemarljiva (npr. z merjenjem pulza na občutljivi tehtnici, ki ga povzroči curek pare, ali z merjenjem izgube mase).
10-3 to 1 Pa.
10-3 do 1 Pa.
Effusion method: By loss of weight or by trapping vaporisate
Efuzijska metoda: Z izgubo mase ali lovljenjem pare
The method is based on the estimation of the mass of test substance flowing out per unit of time of a Knudsen cell (4) in the form of vapour, through a micro-orifice under ultra-vacuum conditions.
Ta metoda temelji na oceni mase preskusne snovi, ki v obliki pare zapusti Knudsenovo celico (4) v časovni enoti skozi mikroodprtino v pogojih ultra visokega vakuuma.
The mass of effused vapour can be obtained either by determining the loss of mass of the cell or by condensing the vapour at low temperature and determining the amount of volatilised substance using chromatographic analysis.
Masa izhajajoče pare se lahko ugotovi tako, da se bodisi določi izguba mase celice bodisi kondenzira para pri nizki temperaturi in določi količina izhlapele snovi s kromatografsko analizo.
The vapour pressure is calculated by applying the Hertz-Knudsen relation.
Parni tlak se izračuna z uporabo Hertz-Knudsenovega razmerja.
Gas saturation method
Metoda z nasičenjem plina
A stream of inert carrier gas is passed over the substance in such a way that it becomes saturated with its vapour.
Preko snovi se usmeri tok inertnega nosilnega plina, tako da se plin nasiti z njeno paro.
The amount of material transported by a known amount of carrier gas is measurable either by collection in a suitable trap or by an intrain analytical technique.
Količina snovi, ki se prenese z znano količino inertnega plina, se lahko izmeri bodisi z zbiranjem v ustrezni lovilnik bodisi z neposredno analitsko tehniko.
This is then used to calculate the vapour pressure at a given temperature.
Ta količina se nato uporabi za izračun parnega tlaka pri dani temperaturi.
10-4 to 1 Pa.
10-4 do 1 Pa.
This method can also be used in the range 1 to 10 Pa providing care is taken.
Ta metoda se lahko uporabi tudi za območje od 1 do 10 Pa, pod pogojem, da smo previdni.
Spinning rotor
Metoda z rotorjem
In the spinning rotor gauge, the actual measuring element is a small steel ball which is suspended in a magnetic field and rotates with high speed.
Pri merilniku z rotorjem je dejanski merilni element jeklena kroglica, ki lebdi v magnetnem polju in se zelo hitro vrti.
The gas pressure is deduced from the pressure-dependent slow-down of the steel ball.
Tlak plina se določi s sklepanjem glede na upočasnitev jeklene kroglice, ki je odvisna od tlaka.
10-4 to 0,5 Pa.
10-4 do 0,5 Pa.
Table:
Tabela
Quality criteria
Merila kakovosti
Measuring Method
Merilna metoda
Estimated Repeatability [7]
Ocenjena ponovljivost [7]
Estimated Reproducibility [7]
Ocenjena ponovljivost [7]
Recommended Range
Priporočeno območje
Existing Standard
Veljavni standard
solid
trdna snov
liquid
tekočina
2 × 103 Pa to 105 Pa
2 × 103 Pa do 105 Pa
10 Pa to 105 Pa [8]
10 Pa do 105 Pa [8]
NFT 20-048 (5)
NET 20-048 (5)
102 Pa to 105 Pa
102 Pa do 105 Pa
Effusion method Vap.Pres.balance
Efuzijska metoda, parnotlačna tehtnica
10-3 Pa to 1 Pa
10-3 do 1 Pa
Effusion method weigt loss
Efuzijska metoda, izguba mase
10-4 Pa to 1 Pa [8]
10-4 Pa do1 Pa [8]
Spinning rotor method
Metoda z rotorjem
10-4 Pa to 0,5 Pa
10-4 Pa do 0,5 Pa
Dynamic measurement
Dinamično merjenje
The measuring apparatus typically consists of a boiling vessel with attached cooler made of glass or metal (figure 1), equipment for measuring the temperature, and equipment for regulating and measuring the pressure.
Merilna aparatura je običajno sestavljena iz vrelne posode s pritrjenim hladilnikom iz stekla ali kovine (slika 1), opreme za merjenje temperature ter opreme za uravnavanje in merjenje tlaka.
A typical measuring apparatus shown in the drawing is made from heat-resistant glass and is composed of five parts:
Značilna merilna aparatura na sliki je narejena iz stekla, odpornega proti vročini, in sestavljena iz petih delov:
The large, partially double-walled tube consists of a ground jacket joint, a cooler, a cooling vessel and an inlet.
Velika cev, delno z dvojno steno, je sestavljena iz brušene ovojne spojke, hladilnika, hladilne posode in vhodne odprtine.
The glass cylinder, with a Cottrell ‘pump’, is mounted in the boiling section of the tube and has a rough surface of crushed glass to avoid ‘bumping’ in the boiling process.
Stekleni valj s Cottrellovo črpalko je nameščen v vrelnem delu cevi in ima grobo površino iz brušenega stekla, da se prepreči „sunkovito udarjanje“ med vrenjem.
The temperature is measured with a suitable temperature sensor (e.g. resistance thermometer, jacket thermocouple) immersed in the apparatus to the point of measurement (No 5, figure 1) through a suitable inlet (e.g. male ground joint).
Temperatura se meri z ustreznim senzorjem temperature (npr. uporovnim termometrom, termočlenom v plašču), ki se skozi primerno odprtino (npr. zunanji (moški) obrus) potopi v aparaturo do merilne točke (št. 5 na sliki 1).
The necessary connections are made to the pressure regulation and measuring equipment.
Aparatura se ustrezno poveže z opremo za uravnavanje in merjenje tlaka.
The bulb, which acts as a buffer volume, is connected with the measuring apparatus by means of a capillary tube.
Bučka, ki deluje kot pufrski volumen, se poveže z merilno aparaturo preko kapilarne cevke.
The boiling vessel is heated by a heating element (e.g. cartridge heater) inserted into the glass apparatus from below.
Vrelna posoda se segreva z grelnim elementom (npr. kartušnim grelnikom), vstavljenim v stekleno aparaturo od spodaj.
The heating current required is set and regulated via a thermocouple.
Potrebni grelni tok se nastavi in uravnava preko termočlena.
The necessary vacuum of between 102 Pa and approximately 105 Pa is produced with a vacuum pump.
Potrebni vakuum med 102 in približno 105 Pa se ustvari z vakuumsko črpalko.
A suitable valve is used to meter air or nitrogen for pressure regulation (measuring range approximately 102 to 105 Pa) and ventilation.
Uporabi se ustrezni ventil za odmerjanje zraka ali dušika za uravnavanje tlaka (merilno območje približno 102 do 105 Pa) in zračenje.
Pressure is measured with a manometer.
Tlak se meri z manometrom.
Measurement procedure
Merilni postopek
The vapour pressure is measured by determining the boiling temperature of the sample at various specified pressures between roughly 103 and 105 Pa.
Parni tlak se meri z določanjem vrelišča vzorca pri različnih točno določenih tlakih med približno 103 in 105 Pa.
A steady temperature under constant pressure indicates that the boiling temperature has been reached.
Nespremenjena temperatura pri konstantnem tlaku kaže, da je bilo doseženo vrelišče.
Frothing substances cannot be measured using this method.
Penečih se snovi ni mogoče meriti s to metodo.
The substance is placed in the clean, dry sample vessel.
Snov se da v čisto in suho vzorčno posodo.
Problems may be encountered with non-powder solids but these can sometimes be solved by heating the cooling jacket.
Pri neuprašenih trdnih snoveh lahko nastanejo težave, ki pa se včasih lahko odpravijo s segrevanjem hladilnega plašča.
Once the vessel has been filled the apparatus is sealed at the flange and the substance degassed.
Ko je posoda napolnjena, se aparatura zatesni pri robnici in snov razplini.
The lowest desired pressure is then set and the heating is switched on.
Nato se nastavi najnižji želeni tlak ter vključi gretje.
At the same time, the temperature sensor is connected to a recorder.
Hkrati se senzor temperature poveže z zapisovalnikom.
Equilibrium is reached when a constant boiling temperature is recorded at constant pressure.
Ravnotežje je doseženo, ko se zapiše konstantno vrelišče pri konstantnem tlaku.
Particular care must be taken to avoid bumping during boiling.
Posebej je treba paziti, da se prepreči sunkovito udarjanje med vrenjem.
In addition, complete condensation must occur on the cooler.
Poleg tega se mora kondenzacija v hladilniku popolnoma končati.
When determining the vapour pressure of low melting solids, care should be taken to avoid the condenser blocking.
Kadar se določa parni tlak trdnih snovi z nizkim tališčem, je treba paziti, da se hladilnik ne zamaši.
After recording this equilibrium point, a higher pressure is set.
Potem ko se zapiše točka ravnotežja, se nastavi višji tlak.
The process is continued in this manner until 105 Pa has been reached (approximately 5 to 10 measuring points in all).
Postopek se nadaljuje na enak način, dokler se ne doseže tlak 105 Pa (skupaj približno 5 do 10 merilnih točk).
As a check, equilibrium points must be repeated at decreasing pressures.
Za potrditev je treba ponoviti točke ravnotežja pri padajočih tlakih.
Static measurement
Statične meritve
The apparatus comprises a container for the sample, a heating and cooling system to regulate the temperature of the sample and measure the temperature.
Aparaturo sestavljajo posoda za vzorec, grelni in hladilni sistem za uravnavanje temperature vzorca in naprava za merjenje temperature.
The apparatus also includes instruments to set and measure the pressure.
Aparatura vključuje tudi inštrumente za uravnavanje in merjenje tlaka.
Figures 2a and 2b illustrate the basic principles involved.
Sliki 2a in 2b prikazujeta osnovne principe metode.
The sample chamber (figure 2a) is bounded on one side by a suitable high-vacuum valve.
Komora za vzorec (slika 2a) se na eni strani poveže z ustreznim visokovakuumskim ventilom.
A U-tube containing a suitable manometer fluid is attached to the other side.
Na drugo stran se pritrdi U-cevka, ki vsebuje ustrezno manometrsko tekočino.
One end of the U-tube branches off to the vacuum pump, the nitrogen cylinder or ventilation valve, and a manometer.
En krak U-cevke vodi do vakuumske črpalke, dušikove jeklenke ali prezračevalnega ventila in do manometra.
A pressure gauge with a pressure indicator can be used instead of a U-tube (figure 2b).
Namesto U-cevke se lahko uporabi merilnik tlaka z indikatorjem tlaka (slika 2b).
In order to regulate the temperature of the sample, the sample vessel together with valve and U-tube or pressure gauge is placed in a bath which is kept at a constant temperature of ±0,2 K. The temperature measurements are taken on the outside wall of the vessel containing the sample or in the vessel itself.
Za uravnavanje temperature vzorca se vzorčna posoda skupaj z ventilom in U-cevko ali manometrom postavi v kopel, ki se vzdržuje pri konstantni temperaturi ±0,2 K. Temperatura se meri ob zunanji steni posode z vzorcem ali v sami posodi.
A vacuum pump with an upstream cooling trap is used to evacuate the apparatus.
Za odzračevanje naprave se uporabi vakuumska črpalka z ohlajeno pastjo na začetku toka.
In method 2a the vapour pressure of the substance is measured indirectly using a zero indicator.
Pri metodi 2a se parni tlak snovi meri posredno z ničelnim indikatorjem.
This takes into account the fact that the density of the fluid in the U-tube alters if the temperature changes greatly.
Pri tem se upošteva, da se gostota tekočine v U-cevki spremeni, če se zelo spremeni temperatura.
The following fluids are suitable for use as zero indicators for the U-tube, depending on the pressure range and the chemical behaviour of the test substance: silicone fluids, phthalates.
Kot ničelni indikatorji za U-cevko so primerne naslednje tekočine, odvisno od območja tlaka in kemijskih lastnosti preskusne snovi: silikonska olja, ftalati.
The test substance must not dissolve noticeably in or react with the U-tube fluid.
Preskusna snov se ne sme vidno topiti v tekočini v U-cevki ali z njo reagirati.
For the manometer, mercury can be used in the range of normal air pressure to 102 Pa, while silicone fluids and phthalates are suitable for use below 102 Pa down to 10 Pa.
Za manometer se lahko uporabijo živo srebro za območje od normalnega zračnega tlaka do 102 Pa ter silikonska olja in ftalati pri območju pod 102 Pa do 10 Pa.
Heatable membrane capacity manometers can even be used at below 10-1 Pa.
Membranski manometri, ki se lahko segrevajo, se lahko uporabljajo tudi pod 10–1 Pa.
There are also other pressure gauges which can be used below 102 Pa.
Obstajajo tudi drugi merilniki tlaka, ki se lahko uporabljajo pod 102 Pa.
Before measuring, all components of the apparatus shown in figure 2 must be cleaned and dried thoroughly.
Pred merjenjem je treba sestavne dele aparature s slike 2 temeljito očistiti in posušiti.
For method 2a, fill the U-tube with the chosen liquid, which must be degassed at an elevated temperature before readings are taken.
Za metodo 2a se U-cevka napolni z izbrano tekočino, ki jo je treba pred odčitavanjem razpliniti pri zvišani temperaturi.
The test substance is placed in the apparatus, which is then closed and the temperature is reduced sufficiently for degassing.
V aparaturo se da preskusna snov, aparatura se zapre in temperatura dovolj zmanjša za razplinjenje.
The temperature must be low enough to ensure that the air is sucked out, but — in the case of multiple component system — it must not alter the composition of the material.
Temperatura mora biti dovolj nizka, da se zagotovi izčrpanje zraka, vendar – pri večkomponentnih sistemih – ne sme povzročiti sprememb v sestavi snovi.
If required, equilibrium can be established more quickly by stirring.
Če je potrebno, se z mešanjem pospeši vzpostavljanje ravnotežja.
The sample can be supercooled with e.g. liquid nitrogen (taking care to avoid condensation of air or pump fluid) or a mixture of ethanol and dry ice.
Vzorec se lahko podhladi npr. s tekočim dušikom (pri čemer je treba paziti, da se zrak ali tekočina v črpalki ne kondenzira) ali zmesjo etanola in suhega ledu.
For low-temperature measurements use a temperature-regulated bath connected to an ultra-cryomat.
Za meritve pri nizkih temperaturah uporabimo kopel z uravnavano temperaturo, povezano z ultra-kriostatom.
With the valve over the sample vessel open, suction is applied for several minutes to remove the air.
Ob odprtem ventilu nad vzorčno posodo se nekaj minut izsesava zrak.
The valve is then closed and the temperature of the sample reduced to the lowest level desired.
Nato se zapre ventil in zmanjša temperatura vzorca do najnižje želene ravni.
If necessary, the degassing operation must be repeated several times.
Če je potrebno, se postopek razplinjevanja večkrat ponovi.
When the sample is heated the vapour pressure increases.
Ko se vzorec segreva, parni tlak narašča.
This alters the equilibrium of the fluid in the U-tube.
To spremeni ravnotežje tekočine v U-cevki.
To compensate for this, nitrogen or air is admitted to the apparatus via a valve until the pressure indicator fluid is at zero again.
Za izravnavo tega učinka, se skozi ventil v aparaturo spusti dušik ali zrak, dokler ni indikator tlaka spet na ničli.
The pressure required for this can be read off a precision manometer at room temperature.
Tlak, potreben za to, se lahko odčita s preciznega manometra pri sobni temperaturi.
This pressure corresponds to the vapour pressure of the substance at that particular measuring temperature.
Ta tlak ustreza parnemu tlaku snovi pri tej merilni temperaturi.
Method 2b is similar but the vapour pressure is read off directly.
Metoda 2b je podobna, le da se parni tlak odčita neposredno.
The temperature-dependence of vapour pressure is determined at suitably small intervals (approximately 5 to 10 measuring points in all) up to the desired maximum.
Odvisnost parnega tlaka od temperature se določi v primernih intervalih (skupaj približno 5 do 10 merilnih točk) do želenega maksimuma.
Low-temperature readings must be repeated as a check.
Za preveritev je treba meritve ponoviti pri nizkih temperaturah.
If the values obtained from the repeated readings do not coincide with the curve obtained for increasing temperature, this may be due to one of the following:
Če vrednosti, dobljene pri ponovljenih meritvah, ne sovpadajo z dobljeno krivuljo za naraščajočo temperaturo, je to lahko posledica enega od naslednjih vzrokov:
the sample still contains air (e.g. high-viscosity materials) or low-boiling substances, which is/are released during heating and can be removed by suction following further supercooling;
V vzorcu je še vedno zrak (npr. snovi z veliko viskoznostjo) ali snovi z nizkim vreliščem, ki se sprosti(-jo) med segrevanjem in se lahko odstrani(-jo) z izsesavanjem po dodatnem podhlajevanju.
the cooling temperature is not low enough.
Temperatura hlajenja ni dovolj nizka.
In this case liquid nitrogen is used as the cooling agent.
V tem primeru se za hlajenje uporabi tekoči dušik.
If either l or 2 is the case, the measurements must be repeated;
Pri primerih 1 in 2 je treba meritve ponoviti.
the substance undergoes a chemical reaction in the temperature range investigated (e.g. decomposition, polymerisation).
V preučevanem temperaturnem območju snov kemično reagira (npr. razpada, polimerizira).
A complete description of this method can be found in reference 7.
Popoln opis te metode lahko najdemo v viru (7).
The principle of the measuring device is shown in figure 3.
Princip merilne naprave je prikazan na sliki 3.
Similarly to the static method described in 1.6.2, the isoteniscope is appropriate for the investigation of solids or liquids.
Podobno kot statična metoda iz 1.6.2 je izoteniskop primeren za preučevanje trdnih snovi ali tekočin.
In the case of liquids, the substance itself serves as the fluid in the auxiliary manometer.
V primeru tekočin sama snov služi kot tekočina v pomožnem manometru.
A quantity of the liquid, sufficient to fill the bulb and the short leg of the manometer section, is put in the isoteniscope.
V izoteniskop se da zadostna količina tekočine, da se napolni bučka in krajši krak manometrskega dela.
The isoteniscope is attached to a vacuum system and evacuated, then filled by nitrogen.
Izoteniskop se pritrdi na vakuumski sistem in odzrači, nato pa napolni z dušikom.
The evacuation and purge of the system is repeated twice to remove residual oxygen.
Odzračevanje in splakovanje sistema se dvakrat ponovi, da se odstrani ves kisik.
The filled isoteniscope is placed in an horizontal position so that the sample spreads out into a thin layer in the sample bulb and manometer section (U-part).
Napolnjen izoteniskop se postavi v vodoraven položaj, tako da se vzorec razlije v tanko plast v vzorčni bučki in manometrskem delu (U-cev).
The pressure of the system is reduced to 133 Pa and the sample gently warmed until it just boils (removal of dissolved fixed gases).
Tlak v sistemu se zmanjša na 133 Pa in vzorec se počasi segreva, dokler ravno ne začne vreti (odstranitev raztopljenih permanentnih plinov).
The isoteniscope is then placed so that the sample returns to the bulb and short leg of the manometer, so that both are entirely filled with liquid.
Izoteniskop se nato postavi tako, da se vzorec vrne v bučko in krajši krak manometra ter se oba popolnoma napolnita s tekočino.
The pressure is maintained as for degassing; the drawn-out tip of the sample bulb is heated with a small flame until sample vapour released expands sufficiently to displace part of the sample from the upper part of the bulb and manometer arm into the manometer section of the isoteniscope, creating a vapour-filled, nitrogen-free space.
Vzdržuje se tlak, kakor pri razplinjevanju; podaljšana konica bučke z vzorcem se segreva nad majhnim plamenom, dokler se sproščene pare vzorca toliko ne razširijo, da izpodrinejo del vzorca iz zgornjega dela bučke in kraka manometra, ga potisnejo v manometrski del izoteniskopa in tako ustvarijo s parami nasičen prostor brez dušika.
The isoteniscope is then placed in a constant temperature bath, and the pressure of nitrogen is adjusted until its pressure equals that of the sample.
Izoteniskop se nato postavi v kopel s konstantno temperaturo, tlak dušika pa se naravna tako, da je enak tlaku vzorca.
Pressure balance is indicated by the manometer section of the isoteniscope.
Ravnotežje tlaka pokaže manometrski del izoteniskopa.
At the equilibrium, the vapour pressure of nitrogen equals the vapour pressure of the substance.
Ob ravnotežju je parni tlak dušika enak parnemu tlaku snovi.
In the case of solids, depending on the pressure and temperature range, the manometer liquids listed in 1.6.2.1 are used.
Pri trdnih snoveh se odvisno od območja tlaka in temperature uporabljajo manometrske tekočine iz 1.6.2.1.
The degassed manometer liquid is filled into a bulge on the long arm of the isoteniscope.
Izboklina na daljšem kraku izoteniskopa se napolni z razplinjeno manometrsko tekočino.
Then the solid to be investigated is placed in the bulb and is degassed at elevated temperature.
Potem se preskusna trdna snov da v bučko in razplini pri zvišani temperaturi.
After that the isoteniscope is inclined so that the manometer liquid can flow into the U-tube.
Nato se izoteniskop nagne tako, da manometrska tekočina steče v U-cevko.
The measurement of vapour pressure as a function of temperature is done according to 1.6.2.
Parni tlak kot funkcija temperature se izmeri v skladu z 1.6.2.
Effusion method: vapour pressure balance
Efuzijska metoda: Parnotlačna tehtnica
Various versions of the apparatus are described in the literature (1).
V literaturi je opisanih več različic aparature (1).
The apparatus described here illustrates the general principle involved (figure 4).
Tukaj opisana aparatura prikazuje glavni princip te metode (slika 4).
Figure 4 shows the main components of the apparatus, comprising a high-vacuum stainless steel or glass container, equipment to produce and measure a vacuum and built-in components to measure the vapour pressure on a balance.
Na sliki 4 so glavni sestavni deli aparature: visokovakuumska posoda iz nerjavečega jekla ali stekla, oprema za ustvarjanje in merjenje vakuuma ter vgrajeni deli za merjenje parnega tlaka na tehtnici.
The following built-in components are included in the apparatus:
V aparaturo so vključeni naslednji vgrajeni sestavni deli:
an evaporator furnace with flange and rotary inlet.
uparjalna peč s prirobnico in vrtljivim dovodom.
The evaporator furnace is a cylindrical vessel, made of e.g. copper or a chemically resistant alloy with good thermal conductivity.
Uparjalna peč je valjasta posoda npr. iz bakra ali kemično odporne zlitine z dobro toplotno prevodnostjo.
A glass vessel with a copper wall can also be used.
Lahko se uporabi tudi steklena posoda z bakreno oblogo.
The furnace has a diameter of approximately 3 to 5 cm and is 2 to 5 cm high.
Polmer peči je približno 3 do 5 cm in višina 2 do 5 cm.
There are between one and three openings of different sizes for the vapour stream.
Peč ima eno do tri odprtine različnih velikosti za tok pare.
The furnace is heated either by a heating spiral around the outside.
Peč se segreva bodisi z grelno ploščo pod njo bodisi z grelno spiralo, ovito okoli njene zunanje strani.
To prevent heat being dissipated to the base plate, the heater is attached to the base plate by a metal with low thermal conductivity (nickel-silver or chromium-nickel steel), e.g. a nickel-silver pipe attached to a rotary inlet if using a furnace with several openings.
Da se prepreči izguba toplote preko osnovne plošče, se grelnik pritrdi na osnovno ploščo s toplotno slabo prevodno kovino (nikelj-srebrovo ali krom-nikljevo jeklo), npr. nikelj-srebrova cev, pritrjena na vrtljivi dovod, če se uporabi peč z več odprtinami.
This arrangement has the advantage of allowing the introduction of a copper bar.
Prednost take konstrukcije je, da se lahko doda bakrena palica.
This allows cooling from the outside using a cooling bath,
To omogoča hlajenje od zunaj s pomočjo hladilne kopeli,