Apparatus for determining a measured value of a measurand in process automation technology and its method of use

Patent metadata

Field	Value
Publication number	US-2019285605-A1
Application number	US-201916427770-A
Country	US
Kind code	A1
Filing date	May 31, 2019
Priority date	Jul 8, 2015
Publication date	Sep 19, 2019
Grant date	—

Abstract

The disclosure includes an apparatus for determining a measured value in a liquid medium, comprising at least a light transmitter, at least one light receiver assigned to the transmitter, a measuring chamber that can be filled with the medium, wherein an optical path runs through the measuring chamber from the transmitter to the receiver. The apparatus includes a dosing apparatus for dosing at least one reagent and/or the medium, and for inserting the dosed reagent and/or the medium into the measuring chamber. The dosing apparatus is designed as a tube, and the tube includes at least a first control point, wherein the volume in the tube from a starting point to a first control point defines the amount of reagent or medium to be inserted into the measuring chamber. The disclosure further includes the use of the apparatus and a method for dosing the reagent.

First claim

1 . An apparatus for determining a measured value of a measurand in a liquid medium by means of an optical sensor comprising:
an optical transmitter for transmitting light; an optical receiver associated with the optical transmitter and configured to receive light transmitted by the optical transmitter and to generate a receiver signal based on the received light; a measuring chamber, wherein an optical measuring path extends through the measuring chamber from the optical transmitter to the optical receiver; a dosing apparatus structured to generate a dosage of a reagent and a dosage of the liquid medium and to provide the dosage of the reagent and the dosage of the liquid medium into the measuring chamber, wherein the dosing apparatus includes a tube, a first light barrier disposed about the tube at a first control point, and a valve module switchable between the reagent, the liquid medium, and the measuring chamber, wherein the tube is transparent to the light of the first light barrier, and wherein the tube is connected with the valve module, and a volume of the tube from a starting point to the first control point defines the dosage of the reagent and the dosage of the liquid medium to be provided into the measuring chamber; and a transmitter including a microcontroller and a memory, wherein the transmitter is configured to generate the first dosage of the at least one reagent and/or the medium based on the signals from the first control point, wherein the transmitted light is converted into the received light by means of interaction along the measuring path in the measuring chamber with the reagent and the medium, and wherein the apparatus is structured to determine the measured value from the receiver signal.

2 . The apparatus of claim 1 , wherein the starting point is a point in the valve module.

3 . The apparatus of claim 2 , wherein the tube has a section having a length, extending between the first control point and the starting point, wherein the length of the section can be adjusted to adapt a volume of the dosage of the reagent and the dosage of the medium to be provided into the measuring chamber.

4 . The apparatus of claim 3 , wherein the tube includes at least one loop in the section.

5 . The apparatus of claim 4 , wherein the tube is embodied to increase or decrease the number of loops in the section, so as to change the volume of the first dosage.

6 . The apparatus of claim 2 , wherein the tube of the dosing apparatus includes at least one loop.

7 . The apparatus of claim 6 , wherein the tube is embodied to increase or decrease the number of loops.

8 . The apparatus of claim 1 , the apparatus further comprising a second light barrier disposed about the tube at a second control point, and wherein the tube is transparent to the light of the second light barrier.

9 . The apparatus of claim 8 , wherein the starting point is the second control point.

10 . The apparatus of claim 9 , wherein the tube has a section having a length, extending between the first control point and the second control point, wherein the length of the section can be adjusted to adapt a volume of the dosage of the reagent and the dosage of the medium to be provided into the measuring chamber.

11 . The apparatus of claim 10 , wherein the tube includes at least one loop in the section and is embodied to increase or decrease the number of loops in the section, so as to change the volume of the first dosage.

12 . The apparatus of claim 1 , wherein the tube of the dosing apparatus is made of polytetrafluorethylene.

13 . The apparatus of claim 1 , wherein the first light barrier is a forked light barrier.

14 . The apparatus of claim 8 , wherein the second light barrier is a forked light barrier.

15 . The apparatus of claim 1 , wherein the dosing apparatus includes at least one air valve configured to introduce air into the tube.

16 . The apparatus of claim 1 , wherein the dosing apparatus includes a pump for conveying the reagent.

17 . The apparatus of claim 1 , wherein the apparatus is employed in an analyzer for determining a measured value of a measurand in a process automation engineering application.

18 . The apparatus of claim 17 , wherein the measurand is a substance concentration.

19 . The apparatus of claim 1 , wherein the transmitted light is converted into the received light by means of absorption along the measuring path in the measuring chamber with the reagent and the medium.

20 . A method of dosing a reagent in an apparatus structured to determine a measured value of a measurand in a liquid medium by means of an optical sensor in a measuring chamber, comprising:
providing a dosing apparatus structured to generate a dosage of the reagent and to provide the dosage of the reagent into the measuring chamber, the dosing apparatus including:
a tube;
a light barrier disposed about the tube at a control point;
an air valve connected with a first end of the tube; and
a valve module switchable between the reagent, the liquid medium, and the measuring chamber,
wherein the tube is transparent to the light of the light barrier, wherein the tube at a second end is connected with the valve module, and wherein a volume of the tube from the valve module to the control point defines the dosage of the reagent to be provided into the measuring chamber;
closing the air valve of the dosing apparatus; switching the valve module to open access to the reagent; switching the valve module to close access to the measuring chamber; conveying the reagent through the valve module, through the tube, and to the control point; opening the air valve and introducing air into the tube; closing the air valve, switching the valve module to close access to the reagent, and switching the valve module to open access to the measuring chamber; and conveying the reagent from the tube, through the valve module, and into the measuring chamber.

Assignees

• Endress Hauser Conducta Gmbh Co Kg

Inventors

• Müller Frank
• Steuerwald Ralf
• Krätschmer Thilo

Classifications

• G01N21/78

  producing a change of colour · CPC title

• G01N21/59

  Transmissivity (G01N21/25 takes precedence) · CPC title

• G01N35/1016 Primary

  Control of the volume dispensed or introduced · CPC title

• G01F11/28

  with stationary measuring chambers having constant volume during measurement · CPC title

• G01N33/1806 Primary

  Biological oxygen demand [BOD] or chemical oxygen demand [COD] · CPC title