CN1017647B - Process of temp. sensing element made of ceramic platium resistance - Google Patents

Abstract

The present invention relates to a manufacturing method of a temperature sensing element made of platinum resistance, which comprises the following steps that a slotted glass rod (1) is used as a skeleton; platinum filaments (2) are wound in a slot; the two thick platinum filaments are used as lead wires (4) for resistance measurement; both ends of each temperature sensing platinum filament (2) are respectively welded with the platinum lead wires (4) which are buried in the glass rod. A ceramic tube (3) is sheathed outside the glass rod; both of the two ends of the glass rod are packed by mixtures (5) of glass powders and ceramic powders; gaps between the glass rod and a sleeve tube are filled with alumina powders (6).

Description

Process of temp. sensing element made of ceramic platium resistance

The present invention relates to the manufacture method of a kind of pinpoint accuracy and high strength resistance temperature measurement element, particularly relate to a kind of manufacture method of glass skeleton pottery armouring platinum resistor temperature measuring element.

The thermal resistance thermometric is to utilize the resistance value of metallic conductor to vary with temperature and the characteristic that changes is carried out thermometric.The resistance temperature measurement element mainly contains following four kinds of structures both at home and abroad at present: around formula, be about to be hung in the ceramic case in two holes or four holes behind the thin platinum filament coiling in (1) ceramic body, the platinum filament, the thermal resistance temperature element shock resistance of this structure is relatively poor.(2) ceramic skeleton, platinum filament externally-wound type are about to thin platinum filament around the ceramic bar outside surface, are coated with glaze and form, and the temperature element thermal stability of this structure is relatively poor.(3) glass skeleton, platinum filament externally-wound type are about to thin platinum filament on the glass bar of cutting, the covering glass bushing, and shortcoming is easily to break up, serviceability temperature is limited by glass softening point, generally can only use 500 ℃.(4) mica frame, platinum filament enwinding type are about to platinum filament and form on the sheet mica sheet, and its weak point is influenced by mica heat expansion or high-temperature outgassing, and serviceability temperature generally can only arrive 420 ℃, and is difficult for making miniaturized component.

The purpose of this invention is to provide a kind of anti-mechanical vibration, and thermal response rapidly, the manufacture method of the extensive repeatable platinum resistor temperature measuring element of high sensitivity and commodity.

Another object of the present invention provides a kind of glass skeleton, the platinum resistor temperature measuring manufacturing method of ceramic package armouring.

The 3rd purpose of the present invention provides a kind of method that encapsulates skeleton.

Other purpose of the present invention and advantage will be below instructions and accompanying drawing in describe.

In these accompanying drawings:

Fig. 1 is the process chart that the present invention makes ceramic industry platinum resistor temperature measuring element;

Fig. 2 is a glass skeleton shaping pre-treatment synoptic diagram;

Fig. 3 is a glass skeleton shaping synoptic diagram;

Fig. 4 is the synoptic diagram after lead-in wire is embedded in the glass skeleton;

Fig. 5 is the welding figure of resistive conductor and lead-in wire;

Fig. 6 is the lead packages synoptic diagram;

Fig. 7 is a coarse adjustment resistance wiring diagram;

Fig. 8 is a temperature element double annealing T-t curve map;

Fig. 9 is a fine tuning resistance wiring diagram;

Figure 10 is two groups of filament solder joint synoptic diagram;

Figure 11 is the ceramic platinum resistance thermometer sensor, temperature-sensing element that the inventive method makes, 1-glass bar wherein, 2-temperature-sensitive platinum filament, 3-ceramic pipe, 4-platinum lead-in wire, 5-glass-ceramic powder, 6-alumina powder.

Platinum resistor temperature measuring element method for making of the present invention is to make skeleton with the cutting glass bar, be that the platinum filament of 0.02～0.05mm is wrapped in the groove with diameter, being generally difilar coil twines, at an end of skeleton with two sections platina silk (long 15mm, diameter 0.3～0.5mm) is made the lead-out wire of resistance measurement, its with thin platinum filament winding welding after press seal in glass skeleton end, clean, annealing, resistance during 0 ℃ of fine tuning is within 100 ± 0.1 Ω, envelope is advanced in the ceramic case, two ends glass micro mist sintering, the ring-like gap filling alumina powder in skeleton and housing, improve thermo-contact, reduce self-heating effect, the element overall dimensions: external diameter is 1.5～5mm, and length is 25～40mm.

Below in conjunction with accompanying drawing method of the present invention is elaborated:

1, cutting:

With glass bar waxdip (the glass bar diameter is φ 0.8～φ 3.8), the wheeled litter groove of getting on the bus then, between the groove pitch be 0.12 or 0.16(mm), through hf etching, require to leave even, smooth thread groove on the glass bar after cleaning. This glass bar will be as the skeleton core of RTD.

2, solder taul:

A, a skeleton core is put on the flame, burnt softly from center section, pull into pointedly relatively, be divided into two sections (see figure 2)s.

B, shaping: remove pointed portion, tail end shaping (see figure 3).

C, melting welding go between: will go between to melt by figure is embedded in the shaping end, and terminals expose about 1mm, requires two lead-in wire root spacings to be not less than 0.4mm, simultaneously with the further shaping (see figure 4) of tail end.

Require the afterbody outward appearance to be sphere, crackle, burr, pore must not be arranged, lead-in wire is firm, non-loosening.

3, clean:

The qualified skeleton chipware that has lead-in wire is placed on boiled in 5% salpeter solution 5 minutes, be placed on again and boil 5 minutes in the distilled water.

4, oven dry:

Skeleton is put into baking oven, treat to cut off the power supply when temperature rises to 80 ℃, when temperature in the baking oven is reduced to 50 ℃, take out.

5, wrapping wire:

(1) determines winding value number, make marks.

(2) every filament one end is enclosed butt-joint around 2～3 on lead riser.Cut off remainder, require every filament and lead-in wire to have only a solder joint (see figure 5).

(3) two are noninductive and around going into groove along helicla flute, require tension uniform, do not have be stacked with, loose, take off groove, with roasting of little fire end to end, cut after itself and glass core are clung, the about 50mm of afterbody anneals with lamp at the place.

(4) the electricity silk is coincide, twine, handle when treating tone pitch in skeleton.

6, pressure head:

With flame that the lead end joint is roasting softening, the labour contractor is pressed into glass, and shaping, makes lead end all wrap the (see figure 6) of entering, and smooth outer surface flawless, slag inclusion etc. are checked contact with multimeter then.

7, clean, anneal (once):

A, boil 5 minutes (KOH) with 10% potassium hydroxide solution, then

B, distillation poach 5 minutes, and use

C, 5% nitric acid (HNO ₃) washing, then

D, usefulness distillation poach 5 minutes,

E, with assembly hang upside down straight down in annealing frame, tailfiber must not unclamp, each part does not collide mutually,

F, the frame of will annealing are packed in the stove, and temperature rises to 620 ℃ and kept 4 hours, and the outage source treats that furnace temperature is reduced to below 60 ℃ to take out.

8, coarse adjustment resistance (see figure 7)

A, will select to survey and good be sandwiched in switch " standard " end, make comparisons on the occasion of platinum resistance

B is allocated to switch " standard ", and the calibration cursor is allocated to " tested " subsequently, and relatively light spot position then will be twisted tailfiber with hand as the resistance deviation, till the luminous point nulling, takes off measured piece,

C, above-mentioned measured piece is loaded in the ice bucket, surveys Ro ℃ of value in+0.2 scope, can continue debugging as being qualified.

9, clean, anneal (secondary):

Cleaning method with once clean identical.

The double annealing temperature is 520 ℃ of insulations 4 hours, cuts off the power supply, treats that furnace temperature is reduced to below 60 ℃ takes out (see figure 8).

10, fine tuning resistance (see figure 9):

A, the ice bucket measuring head is clipped on the winding lead-in wire, puts into the ice bucket cooling, survey R(0 ℃ after 30 minutes) resistance value,

If the b resistance is big, the whipping silk is twisted fried dough twist, resistance is little, and the tailfiber fried dough twist is loosened, and is adjusted to repeatedly to meet till the technical requirement, and fried dough twist density is 2～4 with 1mm and is advisable.

11, sticking tailfiber, solder joint:

A, stick at glass core being about to tailfiber behind the tone pitch on lamp, tailfiber is the longest should not cut surplus behind the haircuts greater than 5mm,

B, carry out solder joint, require two groups of filaments to have only a phase contact (see figure 10) two groups of filament joints.

12, join ceramic pipe, encapsulation

Preliminary work:

A, ceramic pipe is cleaned: method with last twice identical, the taking-up during to 60 ℃ of coolings naturally with 950 ℃ of ceramic pipe annealing.

After b, platinum resistance that will sleeve pipe draw point to clean, oven dry, sleeve pipe: ceramic pipe is inserted in platinum resistance, requires ceramic pipe two to grow skeleton part 2～3mm, insert alumina powder in the pipe

Require alumina powder to tamp.

End socket: after ceramic powder and glass dust potpourri be packaged in ceramic pipe two (mixture ratio is that ceramic powder/glass dust is 6%: 94%) oven dry, carry out lamp worker sintering, sintering time is the longest can not to surpass for 30 seconds.

13, three annealing:

Platinum resistance is hung from above on the annealing frame, and 520 ℃ of the furnace annealings insulation 6 hours of packing into, outage are treated to take out behind the furnace temperature temperature drop to 60 ℃.

14, the detection of dispatching from the factory:

The platinum resistance element is put into ice bucket use the QJ18a electric bridge to survey RO ℃ of value, put into the water boiling point groove then and survey R ₁00 ℃ of value meets the standard of dispatching from the factory, and can dispatch from the factory.

Claims (5)

1, the manufacture method of ceramic platinum resistor temperature measuring element comprises:

(1) cutting of glass bar waxdip is cleaned after the etching, makes and leaves even, smooth thread groove on the glass bar;

(2) the skeleton core is soft from middle burning, be divided into two sections, then at the soft end shaping and the molten shaping end that is embedded in that will go between;

(3) the skeleton core acid that will have lead-in wire was boiled 5 minutes, and boiled 5 minutes with distilled water;

(4) the skeleton core is put into baking oven and dry, then

(5) determine winding value number, with every thin wrapping wire one end and lead-in wire butt-joint, two noninductive and around going into groove along helicla flute;

(6) with flame that lead end is roasting softening, lead riser is pressed into glass and shaping;

(7) boil with alkali lye, distill poach then, acid is boiled again, and the redistillation poach cleans, and then assembly is hung upside down straight down in the annealing frame and anneals in stove;

(8) coarse adjustment resistance is sandwiched in switch " standard " end with what the choosing survey was got well on the occasion of platinum resistance, makes comparisons, switch is allocated to " standard ", the calibration cursor is allocated to " tested " subsequently, relatively light spot position, then to twist tailfiber as the resistance deviation with hand, till the luminous point nulling, take off measured piece, above-mentioned measured piece is loaded in the ice bucket, survey R ℃ of value as being qualified in+0.2 scope, can continue debugging;

(9) clean, anneal;

(10) fine tuning resistance is clipped in the ice bucket measuring head on the winding lead-in wire, puts into the ice bucket cooling, surveys R (0 ℃) resistance value after 30 minutes, if resistance is big, the whipping silk is twisted fried dough twist, resistance is little, the tailfiber fried dough twist is loosened, be adjusted to repeatedly and meet till the technical requirement, fried dough twist density is 2～4 with 1mm and is advisable;

(11) behind tone pitch, tailfiber is sticked at glass core, require two groups of filaments to have only a phase contact;

(12) join ceramic pipe, encapsulation, clean ceramic pipe cleans, anneals, is inserted in platinum resistance, filling alumina powder in the pipe, two ends with ceramic powder be packaged in ceramic pipe two, lamp worker sintering after glass dust mixes;

(13) three annealing, the detection of dispatching from the factory.

2, method according to claim 1, wherein the used acid of waxdip cutting is hydrofluorite.

3, method according to claim 1, wherein to boil with acid be 5% nitric acid in acid.

4, method according to claim 1, wherein alkali lye is 10% sodium hydroxide solution.

5, method according to claim 1, wherein encapsulation is a 6%(weight with ceramic powder/glass dust): 94%(weight).

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