Deutsch: als Temperaturfühler in Differenzmessung geschaltetEnglisch translation: connected/wired as temperature sensors in a differential measuring circuit KudoZ The KudoZ network provides a framework for translators ... More |
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| Glossareintrag (aus Frage unten abgeleitet) | | Deutsch Begriff oder Satz: | als Temperaturfühler in Differenzmessung geschaltet | | Englisch Übersetzung: | connected/wired as temperature sensors in a differential measuring circuit | | Eingetragen von: | Ken Cox |
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Übersetzungen Deutsch > Englisch [PRO] Science - Chemie, -technik / Vapour Pressure Osmometer | | Deutsch Begriff oder Satz: als Temperaturfühler in Differenzmessung geschaltet | "Die Messmethode
Zwei Thermistoren, ***als Temperaturfühler in Differenzmessung geschaltet***, sind in einer thermostatisierten Messzelle hängend angeordnet. Die Temperaturfühler, die zunächst mit Lösungsmitteltropfen umhüllt sind, gleichen sich der Zellentemperatur an, so dass zwischen ihnen kein Temperaturunterschied besteht. Nach Austausch einer der beiden Lösungsmitteltropfen durch einen Lösungstropfen kommt es aufgrund des geringeren Lösungsmitteldampfdruckes über dem Lösungstropfen zur Kondensation von Lösungsmitteldampf. Die entstehende Kondensationswärme führt zu einer messbaren Temperaturerhöhung am Lösungstropfen. Die sich ergebene Temperaturdifferenz zwischen beiden Temperaturfühlern die Bestandteil einer Wheatston’schen Messbrücke mit einer Auflösung von 5x10E-5°C sind, wird in ein Gleichspannungssignal umgewandelt. Der Messwert ist proportional zur osmolalen Konzentration der Lösung kann jedoch durch Wärmeverluste beeinflusst werden. Deshalb ist eine Kalibrierung des Messsystems mit Lösungen bekannter Molalität bzw. Osmolalität erforderlich. Da sich der osmotische Druck von Polymerlösungen in Abhängigkeit von der Konzentration nicht linear verhält, werden mindestens drei Lösungen in abgestufter Konzentration der zu messenden Substanz gemessen. Eine abschließende statistische Berechnung der Messergebnisse durch eine lineare Regressionsberechnung eliminiert das nichtlineare Verhalten."
From an instruction manual about a vapour pressure osmometer. I don't understand what is meant by "als Temperaturfühler in Differenzmessung geschaltet". Connected as temperature sensors in differential measurement??? TIA for your help. |
| | Notiz(en) an den/des Fragesteller(s)
| | connected/wired as temperature sensors in a differential measuring circuit | Erklärung: As you correctly suggested. 'geschalted' in this context means 'connnected' or 'wired' in the sense of jointed in an electrical circuit.
The differential part relates to the fact that the two themistors are aranged in a circuit that senses the difference between the temeratures of the two thermistors, rather than the absolute temperature. As mentioned further on in the text, the actual circuit is a Wheatstone bridge, which is a very common form of differential measuring circuit. Here the thermistors would form one side (two arms) of the bridge.
See e.g.
The Wheatstone Bridge
The Wheatstone bridge circuit in its simplest form (Fig. 516.1) consists of four resistive elements, or bridge arms (R 1 , R 2 , R 3 , R 4 ), connected in a series-parallel arrangement, and an excitation voltage source (E). The electrical connections where pairs of bridge arms are joined to the leadwires from the excitation voltage source are referred to as input corners of the bridge. A differential output voltage (e o ) is measured at the two remaining bridge corners, referred to as output or signal corners.
Fig. 516.1 - Basic Wheatstone Bridge Circuit.
While a mathematical proof is beyond the scope of this publication, it can be shown that if the arm resistances are chosen such that the bridge is resistively symmetrical about an imaginary line drawn through the bridge output corners (as is the case with most commercially available strain gage instrumentation and as assumed in this publication) the differential output voltage (e o ) will be identically zero regardless of the value of the excitation supply voltage. In this condition, the bridge is said to be resistively balanced. If the bridge is not in balance, a differential voltage will be present at the output corners of the bridge, and the magnitude of this output voltage will be proportional to the amount of unbalance.
http://www.vishay.com/brands/measurements_group/guide/tt/tt6... |
| Ausgewählte Antwort von:
Ken Cox Niederlande
| Hinweis von Fragesteller an den AntwortendenIt was pretty hard to select an answer, as all the suggestions were plausible and two of them had good references. But in the end, I was most convinced by Ken's answer. So thanks Ken, but thanks also and commiserations to Zareh, whose answer was also very good. Appreciate everyone's help. 4 KudoZ-Punkte wurden für diese Antwort vergeben |
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25 Min. Antwortsicherheit:  Zustimmung (Netto): +2 |
| as temperatures probes, in differential measurement mode are switched on...
Erklärung: This is my understanding. There are two modes of operation. Gauge mode and differential measurement mode...
-------------------------------------------------- Note added at 26 mins (2007-02-17 03:55:04 GMT) --------------------------------------------------
We could also say "sensors" instead of probes...
-------------------------------------------------- Note added at 36 mins (2007-02-17 04:05:03 GMT) --------------------------------------------------
The following reference shows a diagram of a thermistor in differential mode:
**************
http://www.bbc.co.uk/scotland/education/bitesize/higher/phys...
-------------------------------------------------- Note added at 55 mins (2007-02-17 04:23:41 GMT) --------------------------------------------------
Terribly sorry! **gauge** and **differential** mean the same thing...
-------------------------------------------------- Note added at 1 hr (2007-02-17 04:29:32 GMT) --------------------------------------------------
The following is a more detailed presentation: of course, thermistors translate changes in resistane into temperatures...
http://ej.iop.org/links/rCA,AOBfE/CMgmLj--2xGvCzKaav5vpA/mtv...
Quelle: http://www.olivettii-jet.it/Mems/pdf/Pressure%20Sensor%20TRA...
| Zareh Darakjian Ph.D. Vereinigte Staaten Erfüllt Kriterien Spezialgebiet Muttersprache: Englisch, Armenisch PRO-Punkte in Kategorie: 131
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5 Stunden Antwortsicherheit:   |
17 Stunden Antwortsicherheit:   |
| connected/wired as temperature sensors in a differential measuring circuit
Erklärung: As you correctly suggested. 'geschalted' in this context means 'connnected' or 'wired' in the sense of jointed in an electrical circuit.
The differential part relates to the fact that the two themistors are aranged in a circuit that senses the difference between the temeratures of the two thermistors, rather than the absolute temperature. As mentioned further on in the text, the actual circuit is a Wheatstone bridge, which is a very common form of differential measuring circuit. Here the thermistors would form one side (two arms) of the bridge.
See e.g.
The Wheatstone Bridge
The Wheatstone bridge circuit in its simplest form (Fig. 516.1) consists of four resistive elements, or bridge arms (R 1 , R 2 , R 3 , R 4 ), connected in a series-parallel arrangement, and an excitation voltage source (E). The electrical connections where pairs of bridge arms are joined to the leadwires from the excitation voltage source are referred to as input corners of the bridge. A differential output voltage (e o ) is measured at the two remaining bridge corners, referred to as output or signal corners.
Fig. 516.1 - Basic Wheatstone Bridge Circuit.
While a mathematical proof is beyond the scope of this publication, it can be shown that if the arm resistances are chosen such that the bridge is resistively symmetrical about an imaginary line drawn through the bridge output corners (as is the case with most commercially available strain gage instrumentation and as assumed in this publication) the differential output voltage (e o ) will be identically zero regardless of the value of the excitation supply voltage. In this condition, the bridge is said to be resistively balanced. If the bridge is not in balance, a differential voltage will be present at the output corners of the bridge, and the magnitude of this output voltage will be proportional to the amount of unbalance.
http://www.vishay.com/brands/measurements_group/guide/tt/tt6...
| Ken Cox Niederlande Erfüllt Kriterien Muttersprache: Englisch PRO-Punkte in Kategorie: 39
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| Hinweis von Fragesteller an den Antwortenden| It was pretty hard to select an answer, as all the suggestions were plausible and two of them had good references. But in the end, I was most convinced by Ken's answer. So thanks Ken, but thanks also and commiserations to Zareh, whose answer was also very good. Appreciate everyone's help. |
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