JPH051817Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field This invention is used for titration reagent injection nozzles (hereinafter referred to as nozzles) in automatic titrators, etc., and electrodes and detectors for measuring pH, etc. (hereinafter referred to as electrodes). In addition to holding the sample liquid in the container, it can be automatically inserted into the sample liquid, immersed in it, poured into it, and withdrawn from it.
The present invention relates to a rational operating mechanism for a detection unit in a titration device.

Conventional technology and problems In automatic titrators, the initial pH or ion concentration of the sample solution is usually detected and measured using electrodes before titration is started, and then titration is started. At this time, it is necessary to keep the nozzle for injecting the titration reagent into the sample liquid away from the sample liquid. That is, when the nozzle comes into contact with the liquid during measurement, there is a risk that the concentrated reagent will flow out and diffuse into the sample liquid, changing the pH and ion concentration of the sample liquid.

On the other hand, when performing titration, it is known that titration accuracy is improved by bringing the tip of the nozzle into contact with the sample liquid. This is because if titration is performed with the nozzle separated from the liquid, droplets formed at the tip of the nozzle may fall after injection is stopped, resulting in a positive titration error. The mutual positional relationship of the parts is also said to be related to responsiveness and reproducibility. This fact indicates that the electrode sensing end and
Placing the nozzle tips close together improves the response during titration.
It is known that reproducibility is good in both cases, but
This cannot be achieved unless the tip of the nozzle is placed in contact with the sample liquid.

Conventionally, in this type of device, the electrode and nozzle were operated at the same time, and even if the nozzle is in contact with the liquid, there is no device that allows the electrode to be operated separately. Nakatsuta.

Purpose and Structure of the Present Invention The present invention improves the conventional mechanism of this type, and performs this in conjunction with the operation of lowering the detection end of the electrode and the tip of the nozzle into the sample liquid in the sample container, or removing and lifting it up. At the same time, during the lowering operation (dipping into the sample liquid), the electrode is first immersed in the sample liquid to measure pH, etc., and then during titration, the nozzle tip is lowered to come in contact with the liquid, and the electrode is immersed in the sample liquid to measure pH, etc. The detection end is correctly held at a specified position in the sample liquid, and automatic titration operations can be performed smoothly and accurately with a simple mechanism using only one driving source.

The drawings illustrate the structure of an embodiment of the operating mechanism of the detection unit in the automatic titration apparatus according to the present invention.

In the figure, 1 is a drive motor, and an operation shaft 2, which is a screw shaft, is arranged perpendicularly to this motor 1.
The operating shaft 2 is rotationally driven by attaching the motor 1 and energizing the motor 1. Further, a nozzle holder 3 is provided, one end of which is screwed onto the operating shaft 2, and the other end of which has a holder 6 to which a nozzle 7 can be attached and fixed. An electrode holder 5 is provided below the nozzle holder 3 and is supported via an elastic support 4 such as a coil spring and has a holder 8 for holding an electrode 9.

These nozzles and electrode holders 3 and 5 are moved vertically along a guide 14 by the rotation of the drive motor 1 and the operating shaft 2, and the sample liquid in the sample container 12 set at a predetermined position is moved. 13, electrode 9
And the nozzle 7 can be immersed and removed. At this time, the electrode holder 5 is connected to the nozzle holder 3.
The nozzle holder 3 is provided at the lower part of the nozzle holder 3 and supported by an elastic support 4 so as to be suspended from the nozzle holder 3, and moves up and down with the nozzle holder 3. Therefore, when the drive motor 1 is rotated, the detection end 10 of the electrode 9 is first immersed in the sample liquid, and if it stops at that position, the PH
The following measurements are performed, and then the nozzle 7 descends, and its tip 11 comes into contact with the sample liquid. Then, the electrode holder 5 is moved so that the detection end 10 of the electrode 9 stops at an optimal position within the sample liquid.
is stopped by a stopper 15, and the difference in engagement position with the nozzle holder 3 is absorbed by the elastic support 4. Further, the detection end 10 of the electrode 9 and the nozzle tip 11 are arranged in close proximity to each other, so that highly responsive and highly accurate titration can be performed. By doing so, it is possible to easily select whether only the measurement of PH etc. using the electrode is to be performed or if titration is to be performed at the same time by simply moving the position up and down.

Effects of the present invention By implementing the present invention, automatic titration equipment, etc.
Measurement of pH, etc. and automatic titration can be carried out smoothly, accurately, and accurately with an extremely simple device configuration, and continuous operation is also possible.

[Brief explanation of the drawing]

The drawings are diagrams for explaining the structure of an embodiment of the operating mechanism of the detection unit in the automatic titration apparatus according to the present invention.

Claims (1)

[Scope of utility model claims] An operating shaft that is a screw shaft arranged vertically, a drive motor for rotationally driving the operating shaft, and a drive motor that is screwed onto the operating shaft and can be moved in the vertical direction by rotating the operating shaft. a reagent injection nozzle holder for attaching a reagent injection nozzle; a reagent injection nozzle holder disposed below the reagent injection nozzle holder and supported by the reagent injection nozzle holder via an elastic support; an electrode holder for holding an electrode that is movable in the vertical direction together with the injection nozzle holder; and when the electrode holder moves downward together with the reagent injection nozzle holder, the electrode holder When the designated position is reached,
An operating mechanism for a detection section in a titration apparatus, comprising a stopper that prevents downward movement of the electrode holder and allows downward movement of the reagent injection nozzle holder.