JPS58172513A - Sensor for measuring instrument - Google Patents

Abstract

PURPOSE:To obtain the titled sensor as the sensor for a current meter, a temperature-measuring resistor or a sensor for compensation of temperature, which enables the accurate and rapid measurement of temperature or speed of current for a long time without the possibility of lowering of the precision in measurement, by fitting ceramic covers molded beforehand to the open ends of a ceramic tube. CONSTITUTION:Platinum lead wires 2 are connected to both ends of a fine resistance wire 1 formed by winding spirally a fine platinum wire, and the platinum resistance wire 1 is inserted into a ceramic tube 3 so that the welded part of the lead wires 2 and the wire 1 is held therein. Then, the homogeneous mixture 4 of ceramic sludge is compacted in a gap in the tube, sintered or burnt, and cooled gradually. Next, ceramic covers 6 having the same outline as the end surface of the ceramic tube 3 and provided with holes 5 for insertion of the lead wires 2 are put on both end surfaces of the ceramic tube 3 so that the lead wires 2 are passed through the holes, and both end surfaces of the tube are bonded by a bonding agent 7. A formed article thus obtained is dried at ordinary temperature and then is sintered again in a furnace to bond the ceramic covers 6 completely to the ceramic tube 3, and thereafter it is cooled down gradually to ordinary temperature. Thereby a sensor for measuring instruments prepared by fixing the fine platinum resistance wire 1 in the ceramic 3 with the sintered ceramic 4 and the ceramic covers 6 can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present inventor previously filed the first Utility Application in 19805,
As shown in the figure, the spiral resistance IN8! Connect both wires of I (1) to one end of the lead wire (C2) and insert them into the ceramic tube 6).
We proposed a sensor for a meter that is made by filling the gap between (2) and (2) with ceramic powder, sintering it, and molding it integrally.9.

To manufacture this instrument sensor, a ceramic tube (3
) is filled with slurry of cera-ivy powder and dried, then additionally filled with low-melting point ceramic slurry at both ends of the ceramic tube body ( ) and sintered, forming a ceramic electric sintered body (4) in the center and both ends. Ceramic sintered body (41L).

(411 is integrally filled in the ceramic tube body), when manufacturing the ceramic sintered body (4 m) at both ends, (
It is difficult to make the outer surface of the lead wire (4) symmetrical with respect to the axis and smooth, resulting in small irregularities. When welding Stem Totoru Lead! 1I (2IL), (21), cracks may occur on the outer surface of the ceramic sintered body (4 m), and in either case, the flow of fluid hitting the sensor will be disrupted. There was a drawback that rounding caused uniform disturbances and reduced measurement accuracy.

The present invention aims to improve the above-mentioned drawbacks, and an embodiment will be described with reference to the drawings.As shown in Embodiment 1 and Figure 2, a platinum wire with a diameter of 20 microns is made of a platinum wire with a diameter of about 0.
Connect a 35 ml spirally wound resistance wire (platinum lead wire (2) with a diameter of about 0.0 mm to both ends of the wire) by electric welding, etc. Outer diameter Q made of aluminum oxide or other appropriate material;
'Fml! , insert the thin platinum resistance wire d (□) into the ceramic tube (3) with an inner diameter of 0.5 am so that the welded part of the lead wires (2), (2) and the thin resistance wire (1) fit into the ceramic tube (3), Ceramic slurry, for example, 95 to 60 microns of alumina fine powder with a diameter of 2 microns or less and 5 to 40 microns of hard glass powder with a diameter of 2 microns or less, is placed in the gaps between the Xun and platinum M (1), ■), and (2). A homogeneous mixture (4) made by kneading the fine powder at a ratio of 90 to 80 lO to 200 lO of water is densely packed and dried in a reduced pressure atmosphere at room temperature for 24 to 48 hours to evaporate most of the water added to the fine powder. Next, PK is added, and the temperature is raised from room temperature to about 400°C in about 1 hour. A slurry-like adhesive (7) made by kneading an alumina glass powder mixture with water is applied to the ceramic tube (alumina or other ceramic tube having the same circumference as the layer surface and having a lead wire (adjustable insertion hole (5)). Insert the lead 4m (11)K through the ceramic lid (6), (6) made of an appropriate material, and glue both ends of the ceramic ivy tube (mK) with adhesive (η).

After drying the obtained molded product at room temperature for about 5 hours, it was placed in the oven again, and the temperature was raised from room temperature to about 400°C in about 1 hour, and then heated to about 400°C for 2 hours.
The temperature was maintained at approximately 1,200°C in approximately 3 hours, and the temperature increased to approximately 12
Maintain the temperature at 00℃ for 30 minutes to sinter the adhesive (7) to completely bond the ceramic l1 (6), (6) to the dragon ramic tube (3)K, and slowly cool it to room temperature for about 10 hours. KotoK, platinum resistance thin! Place the sintered ceramic (4) and ceramic lid (6) in the ceramic tube G5.
6) Obtain a dragon sensor for a metering device which is fixed by K.

Practical example As shown in Figures 3 and 4, a ceramic cylinder (3a) with two through holes is prepared, and tungsten lead wires (2), (2) are electrically welded to both ends. Insert the thin resistance wire (1) into the two through holes so that the welded part fits, and connect the ceramic cylinder (31) and the tungsten wire α.
L (2), fill the empty space (m) with a slurry-like homogeneous mixture (4), for example, alumina mold powder kneaded with 10-30-O water, and leave the slurry a) at room temperature. After drying, a tungsten resistance adhesive is applied to both ends of the ceramic cylinder (Sa) by applying an adhesive (g), which is compatible with the ceramic slurry (4) during firing, such as a mixture of alumina glass powder mixed with water. Attach the exposed part of the thin wire (G) and attach the ceramic lid (61) having a cavity to the resistance edge 1! (1)'s hail friend @0 Cylinder body (3a) Adhesive (7) on the end surface
Glue the ceramic cover (6b) with the adhesive (7) and pass it through the hole (5) between the two lead wires (6) in the ceramic cover (6b), which has two lead wire insertion holes (6). It is adhered to the end face of the cylindrical body (31). The obtained molded product was dried at room temperature for about 6 hours, and then argon gas 9δ-1 hydrogen gas 5-
Placed in a furnace maintained at a temperature of 120°C, the temperature was raised from room temperature to about 400°C in about 1 hour, maintained at about 400°C for about 2 hours, and raised to about 1200°C in about 3 hours. about 30℃
The sintered ceramic (4) and Dragon lamik lid (sa), (ah)
Fix it to obtain a senner for a nine-meter column.

In the above embodiment, the resistor 11111 wire (1) K is platinum,
Although tungsten is used, any conductive wire with a large temperature coefficient of resistance, such as nickel, stainless steel, nickel silver, or phosphor bronze, can be used. However, in the case of thin metal wires that are corrosive at high temperatures, the furnace is filled with nitrogen, argon, or hydrogen gas and fired in an atmosphere of 9. - For the lamic tube (ceramic or metal such as mullite or quartz glass can be used as the material of the gradient, and ceramic powder (the material of the material can be alumina, silica, magnesia, quartz glass, etc. or a mixture thereof) However, it is necessary to select and combine the materials of the sintered ceramic tube (2), the sintered ceramic (4), and the resistance wire (5) so that their coefficients of expansion are as equal as possible.

In the present invention, as described above, the pre-formed dragon ramic lid (6) is attached to the open end of the ceramic tube (5), so the filled ceramic ←) of the conventional method is exposed at both ends of the ceramic tube and the end face shape is distorted. Or a lead that becomes a step to lead l II■)! ! When welding (jl a), there is no risk of cracking in the exposed part of the filled ceramic←) and reducing the measurement accuracy, so it can be used as a sensor for flow rate needles, resistance temperature detectors, and temperature compensation sensors for a long time. This has the effect of accurately and quickly defining the temperature or flow rate.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view showing an example of a conventional sensor for measuring instruments.
2 and 3 are cross-sectional views showing an example of the Oli performance sensor of the present invention, and FIG. 4 is a cross-sectional view taken along the line A-5 in FIG. 3. In the figure ((1) is a thin resistance wire, (2) is a beam wire, (gradient is a ceramic tube, (4) is a sintered ceramic, and (6) is a ceramic tube. Eye 7 L・-A ffiJro

Claims (1)

[Claims] 1. Connect both ends of the resistor thin wire (1) to one end of the lead wire (2), respectively, and insert the wire into the ceramic tube (3). Line (υ, (to))l) and 09!
- filled with ceramic powder (4), fired the ceramic powder (4), and provided a lead* (2) insertion hole (6) at the open end of the ceramic tube (S).
6) is bonded with a ceramic adhesive ('/)K, and the ceramic adhesive ()) is sintered and integrally formed. 8. A sensor for an O meter scooper as described in claim 1, in which the firing of Cera no ivy powder (4) and the ceramic adhesive (→O sintering are performed together in the final process @9)
zr:n, 2'! '! 3
, Claim @l11 in which the meter is a flow rate needle. 7-ner for total IIl1gjI as described. 6. The measurement (conversion) sensor is a temperature compensation sensor. 2. Claim 11 [F* sensor for measuring instrument] Ha