SE511075C2

SE511075C2 - Method and device for freezing point measurement

Info

Publication number: SE511075C2
Application number: SE9704373A
Authority: SE
Inventors: Billy Backman
Original assignee: Enator Ab
Priority date: 1997-11-27
Filing date: 1997-11-27
Publication date: 1999-08-02
Also published as: SE9704373D0; AU1515199A; SE9704373L; WO1999031492A1

Abstract

A method and a device for measurement of the freezing point, whereby a cooling device (10) and a heating device (11) are provided in a measuring assembly (18) for repeated cooling down and heating, respectively, of a sample of liquid from a road surface to ice and warmed up again to liquid, and measuring means are provided for continual measuring of the temperature of the sample, so that the sample's freezing point can be determined by registration of the temperature change. A container (13) is provided on a vehicle for collection of a sample of liquid from the road surface. The cooling device (10) and heating device (11) are operatively connected to a control device (14) for repeated cooling of the sample of liquid to ice and warming of the ice to liquid form, and for continual measurement of the sample temperature, and the container (13) comprises dispensing means (15) to automatically empty the container (13) upon completed determination of the sample's freezing point.

Description

lO 15 20 25 30 511 075 2 bestämmas. Peltiér-elementet utgör i sig självt ett mätorgan för mätning av temperaturen genom att särskilda egenskaper hos Peltiér-elementet utnytt- jas. Även omgivningstemperaturen mäts. 10 15 20 25 30 511 075 2 is determined. The Peltiér element itself constitutes a measuring means for measuring the temperature by utilizing special properties of the Peltiér element. The ambient temperature is also measured.

Under nedkylningsfasen kommer det uppmätta temperaturvärdet att uppvisa en diskontinuitet som motsvarar vätskans fryspunkt. Vissa startvär- den för kyl- respektive värmeeffekt tilldelas automatiskt, varefter uppmätt omgivningstemperatur och fryspunkt påverkar effekttillförseln.During the cooling phase, the measured temperature value will have a discontinuity corresponding to the freezing point of the liquid. Certain initial values for cooling and heating power are assigned automatically, after which the measured ambient temperature and freezing point affect the power supply.

Detta kända system för fryspunkts- eller salthaltsmätning fungerar väl och ger en god bild av lokala förhållanden och behovet av ytterligare salttill- försel. Däremot ges ingen möjlighet att insamla uppgifter om salthalt över större geograﬂska områden. Det föreligger också problem att utföra i tiden avgränsade mätningar av fryspunkten hos vätska på en vägbana, eftersom vätska tillförs och avrinner kontinuerligt.This known system for freezing or salinity measurement works well and provides a good picture of local conditions and the need for additional salt supply. On the other hand, there is no opportunity to collect data on salinity over larger geographical areas. There are also problems in performing time-limited measurements of the freezing point of liquid on a road surface, since liquid is supplied and drained continuously.

Uppﬁnningen i sammanfattning Ett syfte med uppfinningen är att förbättra möjligheterna att insamla uppgifter om salthalt över större geograﬂska områden. Ett annat syfte är att undanröja de problem som föreligger med känd teknik beträffande i tiden avgränsade mätningar av fryspunkten.The invention in summary An object of the invention is to improve the possibilities of collecting data on salinity over larger geographical areas. Another object is to eliminate the problems which exist with known technology regarding time-limited measurements of the freezing point.

Ovan angivna syften uppnås genom att uppﬁnningen erhållit de i ned- anstående självständiga patentkrav angivna särdragen. Ytterligare syften och fördelar med uppﬁnningen framgår av efterföljande beskrivning, ritningar och osjälvständiga patentkrav.The objects stated above are achieved by the invention having obtained the features stated in the independent patent claims below. Additional objects and advantages of the invention will be apparent from the following description, drawings, and dependent claims.

Kort beskrivning av ritningarna Uppﬁnningen ska nu närmare beskrivas med hjälp av utföringsexem- pel under hänvisning till bifogade ritningar, på vilka FIG 1 är en schematisk perspektivvy framifrån, som visar en anordning enligt uppﬁnningen före en mätprocess, FIG 2 är en sidovy delvis i sektion av anordningen i FIG 1 under en mät- process och MM avoz-æsps 97-1147 ver 2 ' 10 15 20 25 30 3 511 075 FIG 3 är ett diagram som schematiskt visar temperaturen hos ett prov under ett mätförlopp.Brief description of the drawings The invention will now be described in more detail with the aid of exemplary embodiments with reference to the accompanying drawings, in which Fig. 1 is a schematic perspective view from the front, showing a device according to the invention before a measuring process, Fig. 2 is a side view partly in section of the device in FIG. 1 during a measurement process and MM avoz-æsps 97-1147 ver 2 '10 15 20 25 30 3 511 075 FIG. 3 is a diagram schematically showing the temperature of a sample during a measurement process.

Beskrivning Den i FIG 1 visade anordningen innefattar en bottenplatta 16 och en med denna förbunden styrplatta 17. På bottenplattan 16 är ett mätaggregat 18 i form av en cylindrisk kropp anordnat. Hela anordningen enligt FIG 1 är avsedd att monteras på undersidan av ett fordon i anslutning till ett fordons- hjul, så att vätska från en våt vägbana stänker upp på anordningen då for- donet rör sig.Description The device shown in FIG. 1 comprises a bottom plate 16 and a guide plate 17 connected thereto. On the bottom plate 16 a measuring unit 18 in the form of a cylindrical body is arranged. The entire device according to FIG. 1 is intended to be mounted on the underside of a vehicle in connection with a vehicle wheel, so that liquid from a wet road surface splashes up on the device when the vehicle moves.

Mätaggregatet 18 innefattar en kylanordning 10 och en uppvärm- ningsanordning 11. Enligt ett föredraget utförande utgör ett Peltiér-element 19 både kyl- och uppvärmningsanordning. Peltiér-elementet är anordnat centralt i botten på en behållare 13 utförd som en urtagning i den cylindriska kroppen. Styrplattan 17 medverkar till att vätska, som stänker upp från väg- banan, tillförs behållaren 13.The measuring unit 18 comprises a cooling device 10 and a heating device 11. According to a preferred embodiment, a Peltiér element 19 constitutes both cooling and heating device. The Peltier element is arranged centrally in the bottom of a container 13 designed as a recess in the cylindrical body. The guide plate 17 assists in the liquid 13 which is splashed from the road surface being supplied to the container 13.

Styrplattan 17 innefattar en duk av elastiskt material, t.ex. gummi, som utgör spärrorgan 20 under ett mätförlopp (se FIG 2). Stag 21 förbinder bot- tenplattan 16 med styrplattan 17. Duken är fastspänd mot styrplattan 17 med en låsring 22 (se FIG 2). Mellan mätförloppen rengörs behållaren med ett rengöringsorgan 15, så att en ny mätning avser ny vätska, tex. från ett annat vägparti. Rengöringsorganet 15 kan innefatta ett mot behållaren riktat mun- stycke eller likna-nde för tryckluft. Munstycket är förbundet med en tryckluft- källa på fordonet.The guide plate 17 comprises a cloth of elastic material, e.g. rubber, which constitutes a locking means 20 during a measuring process (see FIG. 2). Bracket 21 connects the bottom plate 16 to the guide plate 17. The cloth is clamped to the guide plate 17 with a locking ring 22 (see FIG. 2). Between the measuring processes, the container is cleaned with a cleaning means 15, so that a new measurement refers to a new liquid, e.g. from another section of road. The cleaning means 15 may comprise a nozzle or similar for compressed air directed towards the container. The nozzle is connected to a source of compressed air on the vehicle.

FIG 2 visar ett utförande av en anordning enligt uppﬁnningen under pågående mätprocess. Spärrorganet 20 har anlagts mot behållaren 13, så däri ansamlad vätska inte kan avgå. Samtidigt förhindras ny vätska att kom- ma in i behållaren. I det visade utförandet har spärrorganet i form av duken utvidgats genom tillförsel av tryckluft till ett utrymme bakom duken.Fig. 2 shows an embodiment of a device according to the invention during an ongoing measuring process. The locking member 20 is mounted against the container 13, so that liquid accumulated therein cannot escape. At the same time, new liquid is prevented from entering the container. In the embodiment shown, the blocking member in the form of the cloth has been expanded by supplying compressed air to a space behind the cloth.

En yta hos Peltiér-elementet 19 är i termisk förbindelse med behålla- ren 13, lämpligen genom att utgöra en del av botten i behållaren. En med MM 97024595 97-11-27 ver. 2 lO 15 20 25 511 075 4 Peltiér-elementet förbunden styranordning 14 är utförd att i detta läge tillföra elektrisk ström till Peltiér-elementet, så att dess ovansida först uppvärms som inledning till ett mätförlopp. Styranordningen 14 kan utföras som ett kretskort åtskilt från själva mätanordningen. l termisk kontakt med Peltiér- elementet är också anordnad en värmeupptagande kropp 23, t.ex. av kop- par.A surface of the Peltiér element 19 is in thermal communication with the container 13, preferably by forming part of the bottom of the container. One with MM 97024595 97-11-27 ver. Peltier element connected control device 14 is designed to supply electric current to the Peltier element in this position, so that its upper side is first heated as an introduction to a measuring process. The control device 14 can be designed as a circuit board separate from the measuring device itself. In thermal contact with the Peltier element, a heat-absorbing body 23 is also arranged, e.g. of copper.

Ett exempel på mätförlopp framgår av FIG 3. I diagrammet återﬁnns tiden t på x-axeln och temperaturen T på y-axeln. För att minska tiden för mätförloppet mäts lämpligen omgivningstemperaturen med separat med sty- ranordningen förbunden mätgivare. Omgivningstemperaturen är markerad vid TS. Genom att omgivningstemperaturen är känd redan vid mätförloppets början inställs Styranordningen automatiskt, så att lämplig effektnivå tillförs Peltiér-elementet. Mätförloppet inleds med en kortare värmefas, vilket visas i kurvan i FIG 3 som ett kontinuerligt stigande temperaturvärde.An example of a measurement sequence is shown in FIG. 3. The diagram shows the time t on the x-axis and the temperature T on the y-axis. To reduce the time for the measurement process, the ambient temperature is suitably measured with a measuring sensor separately connected to the control device. The ambient temperature is marked at TS. Because the ambient temperature is known already at the beginning of the measuring process, the Control Device is set automatically, so that a suitable power level is supplied to the Peltiér element. The measurement process begins with a shorter heating phase, which is shown in the curve in FIG. 3 as a continuously rising temperature value.

Vid viss temperatur övergår mätförloppet i en kylfas under vilken väts- kan i behållaren nedkyls. Vid viss temperatur börjar vätskan övergå i isform, vilket medför att viss värme frigörs. Detta framgår av kurvan som stiger brant. Då temperaturen når vätskans fryspunkt ökar temperaturen språngvis, varefter förblir oförändrad under ett tidsintervall, vilket i diagrammet markeras vid tF. Denna senare diskontinuitet identiﬁeras av styranordningen som väts- kans fryspunkt, då temperaturen är TF. En med styranordningen 14 förbun- den displayenhet (ej visad) indikerar för föraren av fordonet den aktuella temperaturen. Motsvarande temperaturvärde kan också lagras i en minnes- het (ej visad) försenare genomgång och statistiksammanställning.At a certain temperature, the measuring process changes into a cooling phase during which the liquid in the container cools down. At a certain temperature, the liquid begins to change into ice form, which means that some heat is released. This is evident from the curve that rises steeply. When the temperature reaches the freezing point of the liquid, the temperature increases abruptly, after which it remains unchanged for a time interval, which in the diagram is marked at tF. This latter discontinuity is identified by the control device as the freezing point of the liquid, when the temperature is TF. A display unit (not shown) connected to the control device 14 indicates to the driver of the vehicle the current temperature. The corresponding temperature value can also be stored in a memory (not shown) delayed review and compilation of statistics.

MM 97024595 97-11-27 ver. 2MM 97024595 97-11-27 ver. 2

Claims

10 15 20 25 30 5 ”511075 PATENT REQUIREMENTS

A method of freezing point measurement, wherein a liquid sample from a road surface is repeatedly cooled to ice and reheated to liquid and the temperature of the sample is continuously measured, so that the freezing point of the sample can be determined by recording the temperature course, characterized in that a liquid samples are collected from the road surface in a container by collecting the splash from a rotating vehicle wheel, cooling the liquid sample to ice and re-heating it to liquid and continuously measuring the temperature of the sample, determining the freezing point of the sample and automatically emptying the temperature after completing the freezing point of the sample.

2. A method according to claim 1, characterized in that liquid is prevented from entering the container, during the registration of the temperature course.

3. A claim according to claim 1, characterized in that the freezing point of the sample is determined by recording the temperature course during at least one cooling phase.

4. A method according to claim 1, characterized in that the liquid sample in the container is heated or cooled by a Peltiér element.

Freezing point measuring device, wherein a cooling device (10) and a heating device (11) are arranged in a measuring unit (18) for repeated cooling and heating of a liquid sample from a roadway to ice and back to liquid and measuring means (12). are arranged for continuous measurement of the temperature of the sample, so that the freezing point of the sample can be determined by recording the temperature course, characterized by AH 970245pS 97-11-27 ver, 2 10 15 20 25 30 51110715 that a container (13) is arranged on a vehicle for collecting a liquid sample from the road surface in the form of the stench from a vehicle wheel, that the cooling device (10) and the heating device (11) are operatively connected to a single control device (14) for repeatedly cooling the liquid sample to ice and heating the ice to liquid and for continuous measurement of the temperature of the sample, that the control device is designed to determine the freezing point of the sample by registering the temperature course and that * the container (13) enters comprises emptying means (15) for automatic emptying of the container (13) after complete determination of the freezing point of the sample.

Device according to claim 5, characterized in that blocking means (20) are arranged to prevent the inflow of liquid during ongoing freezing point supply.

Device according to claim 6, characterized in that the locking member (20) is designed as a lid (13) which can be closed.

Device according to claim 6, characterized in that the locking means (20) is designed as a rubber cloth, that the rubber cloth is clamped on a guide plate (17) above the container - (13) and that the rubber cloth is expandable by supplying a pressure medium, so that the container (13) is closed.

Device according to claim 5, characterized in that a Peltiér element (19) forms the cooling device (10) and the heating device (11).

Device according to claim 5, characterized in that the container (13) is designed as a recess in the measuring unit (18).

Device according to claim 10, characterized by AH 97024Sps 97-11-27 ver. 2 511075 7% that a cleaning means (15) is arranged for cleaning the container (13) between the measuring caps.

Device according to claim 11, characterized in that the cleaning means (15) comprises a compressed air nozzle. AH 97024Sps 97-11-27 ver, 2