CN86108025A - Qct - Google Patents
Qct Download PDFInfo
- Publication number
- CN86108025A CN86108025A CN 86108025 CN86108025A CN86108025A CN 86108025 A CN86108025 A CN 86108025A CN 86108025 CN86108025 CN 86108025 CN 86108025 A CN86108025 A CN 86108025A CN 86108025 A CN86108025 A CN 86108025A
- Authority
- CN
- China
- Prior art keywords
- temperature
- crystal
- thermometric
- temperature measuring
- circuit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Images
Landscapes
- Oscillators With Electromechanical Resonators (AREA)
Abstract
Utilize quartz-crystal resonance frequency to change with variation of temperature, it is the method that generally adopts both at home and abroad at present that this characteristic is measured temperature.But prior art does not solve the problem that crystal separates with oscillatory circuit.The present invention adopts the quartz crystal of homemade Y+0 ° cut type and pulse shaping circuit that one is skillfully constructed to constitute the thermometric oscillator, and make the concentric cable of (γ/2 ± λ/8) wavelength of using 20 meters long between the two connect (λ is the wavelength of oscillation frequency), the ideal transducer that utilizes the crystal piezoelectric effect to measure physical quantitys such as temperature, pressure can be provided in this way.The present invention utilizes above-mentioned temperature probe and Microcomputer Technology to develop a kind of intelligentized temperature measuring device.
Description
As everyone knows, the resonance frequency of the quartz-crystal resonator of certain cut type changes with variation of temperature, therefore can calculate the height of temperature by measuring its oscillation frequency.Simultaneously, quartz crystal has comparatively stable physicochemical property, makees temperature sensor and the thermometer made has good stability, is convenient to advantages such as digitized measurement with quartz crystal.Existing dissimilar both at home and abroad at present QCTs come out.
But, because depend on that with its precision of crystal thermometric the stability (being actually the repeatability of same temperature) of thermometric crystal oscillator is for addressing this problem, usually crystal and tank can only be done together, doing like this is stability for fear of the effect of parasitic capacitance frequency.The QCT that we succeed in developing first is exactly to adopt oscillatory circuit is made on the long and narrow printed-wiring board (PWB) of a fritter, the thermometric crystal places the termination of this piece plate, the oscillator that this is whole is contained in the metal sleeve, sealing then, though solved the problem of frequency stability like this, make that but the volume of sensor is big, thermal time constant is big, can not be applicable to the temperature field measurement that rate of change is bigger.The electronic component of oscillatory circuit places by the thermometric field together with the thermometric crystal simultaneously, thereby has limited temperature-measuring range.
The present invention is intended to address the aforementioned drawbacks, and seeks a kind of technical scheme that crystal is separated with oscillatory circuit.Simultaneously abundant using miniature computer technology.Be quick on the draw for thermometry provides a kind of, accurately, precision height, intelligent device that temperature-measuring range is big.
The present invention adopts the quartz crystal of homemade Y+O ° cut type and pulse shaping circuit that one is skillfully constructed to constitute the thermometric oscillator and both is separated to solve open question in the prior art.
Thermometric crystal 1 connects with two concentric cable with (λ/2 ± λ/8) wavelength of 20 meters long between the shaping circuit 2, and λ is the wavelength of oscillation frequency.Oscillatory circuit adopts cmos device, guarantees the stability of crystal oscillation frequency, and a Sheffer stroke gate two ends amplitude limit network in parallel to guarantee that crystal only has the lower level of drive, does not cause crystal to produce self-heating and brought disturbance by the thermometric field.
Can provide the piezoelectric effect of utilizing crystal to measure high sensitivity, the high-resolution ideal transducer of physical quantitys such as temperature, pressure in this way.
The intelligent temperature measuring device that the present invention also provides the above-mentioned temperature probe of a kind of usefulness and adopts the Microcomputer Technology development.
The main performance of this instrument:
1. temperature-measuring range :-40 ℃～+ 80 ℃
2. absolute precision: ± 0.02 ℃ (depend on and demarcate temperature accuracy)
3. resolution: 1 * 10
-4℃
4. degree of stability: 0.01～0.02 ℃
5. main frame has self-checking function, has ten mean values of frequency/temperature to show, can print by timing difference, and fixed difference difference is printed.
6.ROM capacity is 4K, interior band clock stability is 1 * 10
-6
7. thermal time constant＜1 minute
8. but adding circuit amplifier remote measurement reaches more than 100 meters.
Fig. 2 is this principle of instrument block scheme, the temperature variant frequency signal that comes from oscillator amplifies buffer amplifier, then under the commander of input instruction, enter host CPU, make frequency signal become corresponding temperature indicating value by the CPU software processes, directly demonstrate by the temperature value of thermometric field by display then.
This instrument medium frequency temperature profile relation is:
f（t）＝f
o+αt+βt
2+γt
3
The resonance frequency of crystal when f(t) being temperature t.f
oThe zero degree frequency of crystal when being 0 ℃, α, β, γ are respectively one, two, three temperature coefficient, and the nominal frequency of this instrument thermometric crystal is 5000KHZ, and α is 430HZ/ ℃, and β is 0.430HZ/ ℃, γ is ± 0.006HZ/ ℃.This instrument makes full use of the microprocessor technology, has used unique repeatedly formula to calculate in data processing and has added look-up table, has accelerated arithmetic speed.
Linear data after the conversion of overfrequency-temperature deposits ROM in, and in order to calling, in the occasion that needs show, computing machine also send display to show through interface circuit Temperature numerical simultaneously.
Utilize the overall process of crystal thermometric to finish like this.
Fig. 1 is a temperature sensor schematic diagram of the present invention.Among the figure: the 1st, thermometric crystal, the 2nd, concentric cable, the 3rd, amplitude limit network, the 4th, resistance, 5 and 6 right and wrong doors.Dotted line 7 gets up 3,4,5,6 frames, represents that their form shaping circuit unit, and 2 couple together 1 and 7, and 3 are connected in parallel on 4 and 5, work to limit pulse height.In QCT provided by the invention, 5 and 6 all adopt cmos device.
Claims (8)
1, a kind ofly makees the temperature measuring equipment of temperature sensor, it is characterized in that the temperature measuring equipment of the microprocessorization of thermometric crystal and oscillatory circuit divergence type with crystal.
2, said as claim 1, it is characterized in that the thermometric crystal of sensor is separating more than 20 meters with oscillatory circuit.
3, said as claim 2, it is characterized in that this separate mode be crystal with between the oscillatory circuit with the concentric cable of two (λ/2 ± λ/8) be connected (wavelength that λ is resonance frequency).
4, said as claim 3, it is characterized in that the circuit of sensor has the version shown in the figure (1).
5, as claim 1,4 said, it is characterized in that having temperature measuring equipment as technical feature cited in the description of the invention.
6, said as claim 1, it is characterized in that the circuit structure of instrument satisfies as scheming the block scheme shown in (2).
7, as claim 1,6 said, the device that it is characterized in that having direct demonstration dut temperature and show the light-emitting diode display of the frequency values under the different temperatures.
8, said as claim 1 and 5, it is characterized in that the reduction formula that is frequency-temperature satisfies f(t)=f
o+ α t+ β t
2+ γ t
3The temperature measuring equipment of microcomputerization of computing formula.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 86108025 CN86108025A (en) | 1986-11-18 | 1986-11-18 | Qct |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 86108025 CN86108025A (en) | 1986-11-18 | 1986-11-18 | Qct |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN86108025A true CN86108025A (en) | 1988-06-01 |
Family
ID=4803771
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 86108025 Pending CN86108025A (en) | 1986-11-18 | 1986-11-18 | Qct |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN86108025A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102435342A (en) * | 2011-10-11 | 2012-05-02 | 应达利电子(深圳)有限公司 | Temperature measuring instrument and method based on AT-cut quartz crystal resonator |
| CN103884446A (en) * | 2014-04-08 | 2014-06-25 | 章礼道 | Quartz crystal thermometer based on Beidou time service |
| CN106840445A (en) * | 2017-03-30 | 2017-06-13 | 中国地震局地壳应力研究所 | A kind of high-precision quartz crystal temperature effect meter |
-
1986
- 1986-11-18 CN CN 86108025 patent/CN86108025A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102435342A (en) * | 2011-10-11 | 2012-05-02 | 应达利电子(深圳)有限公司 | Temperature measuring instrument and method based on AT-cut quartz crystal resonator |
| CN103884446A (en) * | 2014-04-08 | 2014-06-25 | 章礼道 | Quartz crystal thermometer based on Beidou time service |
| CN106840445A (en) * | 2017-03-30 | 2017-06-13 | 中国地震局地壳应力研究所 | A kind of high-precision quartz crystal temperature effect meter |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4372164A (en) | Industrial process control instrument employing a resonant sensor | |
| CN101876567B (en) | Tracking testing system of resonant frequency of quartz crystal microbalance and method thereof | |
| CN101634595B (en) | High-precision platinum resistor temperature measuring system and temperature measuring method based on same | |
| WO1989010545A2 (en) | Capacitive pressure sensor | |
| CN111766771A (en) | Voltage-controlled crystal oscillator taming-based time interval measuring method and system | |
| CN114629438A (en) | Acceleration compensation anti-vibration crystal oscillator and compensation method thereof | |
| CN86108025A (en) | Qct | |
| CN102508034B (en) | Method and device for measuring parameters of micro solid gyroscope equivalent circuit | |
| JP2675733B2 (en) | Chemical sensing equipment | |
| US3008332A (en) | Supersonic pressure gauge | |
| JP3243100B2 (en) | Temperature phase shift circuit and coordinate input device | |
| US5610838A (en) | Coordinate input device for calculating a coordinate of an input position of an applied vibration | |
| JPH07104248B2 (en) | Vibration period detection method in vibration type densitometer | |
| JP2568145Y2 (en) | Signal time difference measuring device | |
| CN109298238A (en) | A kind of frequency measurement method and its measuring system | |
| CN1062214A (en) | Frequency-converting measuring system for micro-changing of small capacitance | |
| JP2003106906A (en) | Temperature measuring method | |
| CN211234628U (en) | Liquid level meter with high accuracy | |
| SU1725069A1 (en) | Angular movement sensor | |
| Zhou et al. | An MCXO test system and its function in MCXO performances | |
| JPS54156580A (en) | Temperature measuring apparatus | |
| JPS6275315A (en) | Displacement measuring circuit | |
| SU1405021A1 (en) | Apparatus for measuring time duration of pulses | |
| SU1638557A1 (en) | Liquid level meter | |
| JPS61138131A (en) | Crystal thermometer |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| C06 | Publication | ||
| PB01 | Publication | ||
| WD01 | Invention patent application deemed withdrawn after publication |