JPS612064A - Detector for concentration of hydrogen or steam in gas - Google Patents

Abstract

PURPOSE:To reduce the cost of an element by bringing the outside electrode layer of the element into direct press contact with a plug body to maintain an electrical contact therewith and forming the inside electrode layer thereof into a shape having no conductivity with the plug body. CONSTITUTION:The plug body 4 is screwed to the gas chamber wall 10 of a measuring gas chamber 2 by a screw part. The element 3 is caulked to the part of the body 4 projecting into the chamber 2, by which the standard gas and measuring gas of a detector 1 are hermetically shut off. The outside electrode layer 8 made by calcining platinum powder, etc. is formed on the outside surface of the element 3. On the other hand, the inside electrode layer 9 is adhered to the inside surface of the element 3 in the same manner as for the layer 8. The element 3 has no electrode layer on the outside peripheral part and is made into the construction in which the layer 9 and the body 4 are insulated by the element 3. A terminal 5 is fixed to an insulator 11 for the terminal and the electromotive force generated in the layer 9 is conducted through a lead 14 by an adhering part 13 to the terminal 5. The electromotive force is thus generated between the layers 8 and 9 when the concn. of the hydrogen or steam in the gas in contact with both surfaces of the element 3 is different. The generated electromotive force is conducted to the body 4 and the terminal 5, by which the concn. of the hydrogen or steam is detected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydrogen or water vapor concentration detector in gas using an element mainly composed of strontium oxide or cerium oxide.

FIG. 1 shows the structure and installation state of a hydrogen or water vapor concentration detector in gas using the above-mentioned element, which has been developed in recent years. That is, in this conventional device, /a is a hydrogen or water vapor concentration detector; Reference numeral 2a denotes a measurement gas chamber, and the hydrogen or water vapor concentration detector/a is screwed into the gas chamber wall 10a of the measurement gas chamber 2a by a threaded portion of a plug 11a.
The element 3a held by the element 3a has a cylindrical shape, and the side protruding into the measurement gas chamber 2a is hermetically closed, and the other end is open and has a terminal sa fixed thereto for drawing out the electromotive force. ing. Then, on the outer and inner surfaces of the element 3a, there are an outer electrode layer 1fa and an inner electrode layer 9a made of platinum or the like, respectively, and a porous layer is formed so that these electrode layers a and 9a can contact the surface of the element 3a. The outer electrode layer fa is electrically connected to the stopper 11a through the conductive gasket Oa, and the inner electrode layer qa is electrically connected to the terminal Sa. The structure is such that an electromotive force logarithmically proportional to the ratio is generated between the plug body 11a and the terminal Sa. Furthermore, 7a
is a gasket.

In this conventional structure described above, the element 3a is a kind of ceramic, and is molded and pre-fired.

It is difficult to manufacture a cylindrical shape with one end closed because it requires complicated processes such as processing and firing one piece. Furthermore, spraying and baking electrode layers such as platinum on the inner and outer surfaces pose problems such as non-uniformity of the electrode layer and difficulty in special processing. Furthermore, the element 3a is fitted into the stopper lla via the conductive gasket Oa, and is electrically and mechanically fixed. The element 3a expands, causing loosening between the plug 11a and the element 30, and the electrical conduction between the outer electrode layer fa and the conductive casing (A) and the plug 11a becomes incomplete, and both electrode layers ga, Only the extraction of the electromotive force generated at 9a becomes unstable.

As described above, conventional hydrogen or water vapor concentration detectors have drawbacks such as non-uniform performance due to manufacturing difficulties, high costs, structural instability of electrical continuity, and poor durability.

The purpose of this invention is to eliminate the above-mentioned drawbacks of the prior art,
The object of the present invention is to provide a hydrogen or water vapor concentration detector that is inexpensive, provides stable performance, and has good durability.

More specifically, the objectives and characteristics of this invention are, firstly, to simplify the shape of a proton conductive solid electrolyte element;
In addition to facilitating processing, coating and baking both the inner and outer electrodes facilitates work, and also facilitates processing to improve the durability of the electrode surfaces.Secondly, the above-mentioned elements on the plug body The purpose of this invention is to provide a structure that prevents loosening between the plug and the element due to a difference in thermal expansion caused by a rise in temperature.

The second figure in the drawing shows an embodiment of a hydrogen or water vapor concentration detector in waste using the above element having the structure of the present invention. They are essentially the same, but have been structurally improved. Hereinafter, this invention will be explained in detail regarding No. 2 l:yJ.

First, the plug of the hydrogen or water vapor concentration detector is screwed into the gas chamber wall 10 of the measuring gas chamber 2, and the element 3
is a circular flat plate with four cylindrical projecting edges on its outer periphery, and is fitted and caulked into the protruding part of the stopper L into the measurement gas chamber 2, thereby allowing the standard gas and measurement gas of the detector/ and is hermetically sealed off.

Further, on the outer surface of the element 3, that is, the surface on the inside side of the measurement gas chamber, an outer electrode layer g is adhered by baking platinum powder, etc., and this outer electrode layer g is coated on the entire surface as shown in the figure. The cap 44 is brought into pressure contact with the stopper 44 to maintain electrical contact. On the other hand, on the inner surface of the element 3, that is, the surface on the standard gas side, an inner electrode layer 9 is adhered in the same way as the outer electrode layer, and as shown in FIG. Electrode layer and plug
means a structure insulated by the element 3 described above. Plug body q
A terminal insulator carrying a terminal j is fixed to the outside of the terminal j, and the electromotive force generated on the inner surface electrode layer 9 is electrically connected by the adhesive part /3, passes through the lead /Il, and is transferred to the terminal S. be guided. Here, the terminal insulator// is provided with seven or more ventilation holes/2, so that standard gas can be vented.

In the hydrogen or water vapor concentration detector/having the structure of the present invention as described above, when the hydrogen or water vapor concentrations in the gas in contact with both sides of the element 3 are different from each other, the element 3 is placed on the side where H2 ions are concentrated. Because it moves to the thinner side,
Generating an electromotive force between the outer electrode layer g and the inner electrode layer w,
This is led to the outside through the plug and the terminal.

This principle is the same as in conventional detectors. Note that 7 is a gasket.

Since the hydrogen or water vapor concentration detector of the present invention is constructed as described above, the shape of the proton conductive solid electrolyte element P is extremely simplified compared to conventional detectors, so it is easy to manufacture. This makes it easy to adhere the electrode layers to both sides, and has great effects such as reducing costs and ensuring uniformity in hydrogen 7 or water vapor concentration detection characteristics.

Furthermore, since the electrode layer can be easily processed to improve durability, it also contributes to the possibility of improving durability.

Further, since the width of the caulked portion of the element to the plug body can be made short, the present invention has great effects, such as preventing problems such as loosening of the caulked portion due to thermal expansion difference due to temperature rise, leakage of airtightness, and poor electrical contact.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a conventional detector, FIG. 2 is a longitudinal sectional view of a detector of the present invention, FIG. 3 is a plan view of the same circular plate-like element, and FIG. 1 is a bottom view of the same. /, /a...detector, 2, 2t1. , measurement gas chamber, 3.
3a, Element, g, +a, Plug, 5, 5a... Terminal, Otsu a... Conductive gasket, 7, 7a... Gasket, Za, Zaa, Outer electrode layer, 9゜qa... , inner electrode layer, 10,10 tl・, gas chamber wall, //,, insulator for terminal, /2・1 ventilation hole, /3,・adhesive part, /4Z,, lead, patent applicant Tokyo Ceramics Co., Ltd. Company Figure 1 Figure 2

Claims (1)

[Claims] In a gas hydrogen or water vapor concentration detector using a proton-conductive solid electrolyte element mainly composed of strontium oxide and cerium oxide, a circular flat element with an annular protrusion on the outer periphery is inserted into a metal stopper. , caulk and hold;
The outer electrode layer of the element is brought into direct pressure contact with the plug to maintain electrical contact, the inner electrode layer of the element is shaped to be non-conductive with the plug, and the terminal is supported on an insulator separately fixed to the plug. 1. A hydrogen or water vapor concentration detector in a gas, characterized in that the inner electrode layer side is electrically connected to the standard gas, and the outer electrode layer side is made to be in contact with an atmospheric gas.