CN112798130B - Multi-path temperature measuring device and multi-path temperature measuring circuit thereof - Google Patents
Multi-path temperature measuring device and multi-path temperature measuring circuit thereof Download PDFInfo
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- CN112798130B CN112798130B CN202011608087.2A CN202011608087A CN112798130B CN 112798130 B CN112798130 B CN 112798130B CN 202011608087 A CN202011608087 A CN 202011608087A CN 112798130 B CN112798130 B CN 112798130B
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/18—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer
- G01K7/20—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a linear resistance, e.g. platinum resistance thermometer in a specially-adapted circuit, e.g. bridge circuit
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
- G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
- G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
- G01K7/24—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor in a specially-adapted circuit, e.g. bridge circuit
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Abstract
The invention discloses a multi-path temperature measuring device and a multi-path temperature measuring circuit used by the same. The temperature measuring element adopts a four-wire system connection method, so that the influence of the wire resistance on the temperature measuring precision is eliminated; the two end lead wires of at least two temperature measuring elements are connected with the same acquisition channel of the voltage measurer, signals of the temperature measuring elements acquired by the voltage measurer are controlled by using a gating switch, multiplexing of the acquisition channels of the voltage measurer is achieved, the use amount of the acquisition channels of the voltage measurer is saved, the complexity and cost of a temperature measuring circuit are reduced, a signal relay is used as the gating switch, and leakage current of the gating switch is eliminated; the multi-path temperature measuring device and wires, connectors, gating switches and the like in the multi-path temperature measuring circuit are matched, so that the wire impedance, the wire-to-wire crosstalk, the environmental electromagnetic interference and interference noise signals introduced by the thermoelectric effect are reduced, and the temperature measuring precision is improved.
Description
Technical Field
The invention belongs to the technical field of temperature measurement, and relates to a multi-path temperature measuring device and a multi-path temperature measuring circuit thereof.
Background
The use of high precision thermometers is often required in advanced manufacturing fields, such as in lithographic apparatus in the semiconductor manufacturing field, where many sites require temperature control in the range of 20-24 ℃ and where the temperature does not fluctuate over time by more than 0.05 ℃; in order to meet the requirement of temperature control accuracy, a temperature measuring device, which is one of temperature feedback control components, needs to have excellent measurement accuracy, and it is generally required that the measurement accuracy of the temperature measuring device is better than 0.01 ℃ or even 0.001 ℃. To realize high-precision temperature measurement, a temperature measuring element is required to have good precision, and a power and signal processing circuit is also required to be matched with the temperature measuring element.
Resistive electrical elements such as resistance temperature detectors (RESISTANCE TEMPERATURE DETECTOR, RTDs) or thermistors are commonly used in the art as temperature sensing elements. RTD is a resistor made of a metal material, whose resistance varies with a change in temperature; the RTD is a high-precision temperature measuring element, is suitable for the temperature range of minus 200 ℃ to +850 ℃, has excellent long-term stability, is relatively simple in signal processing method, and is widely applied to the field of precise temperature measurement. The thermistor is made of metal oxide, the resistance of the thermistor can be changed along with the temperature change, the resistance value of the common thermistor can be reduced along with the temperature rise, the thermistor can generally work in the range of-40 ℃ to +150 ℃, the accuracy is optimal at 0 ℃ to 100 ℃, the cost of the thermistor is low, and the nonlinearity degree of the relation between the resistance value and the temperature is higher. The basic principle of using RTD or thermistor to measure temperature is to measure resistance value, in order to eliminate the influence of wire resistance on temperature measurement accuracy, four-wire connection method can be adopted for the temperature measurement resistor, a current source is used to provide stable current for the temperature measurement resistor, and then wires are led out from two ends of the temperature measurement resistor to be connected to an input port of a voltage measurer. Commonly, one port of the voltage measurer is correspondingly connected with a temperature measuring resistor; however, the number of channels of the voltage measurer needed when the number of temperature measuring resistors is large may be large, which will increase the cost of the system, especially for high-precision temperature measuring devices, which will obviously increase the complexity and cost of the system. In addition, in a high-precision temperature measuring device, besides the precision of an RTD as a temperature measuring element, the precision of temperature measurement can be affected, and factors such as resistance, impedance matching, signal crosstalk, thermoelectric effect and the like of a wire of a temperature measuring circuit can also affect the precision of temperature measurement; particularly, in the occasion that the temperature measurement precision is better than 0.01 ℃, the precision of the temperature measurement circuit has obvious influence on the temperature measurement precision.
Disclosure of Invention
The invention aims to provide a multi-path temperature measuring device which uses a gating switch to realize multiplexing of voltage measurer channels and comprises a plurality of resistive temperature measuring elements, and a temperature measuring circuit which is suitable for measuring temperature by matching with the plurality of resistive temperature measuring elements.
The invention comprises a temperature measuring circuit and at least two temperature measuring elements of temperature measuring resistors; the temperature measuring element is a resistive electric element, and the resistance value of the temperature measuring element changes along with the change of temperature; the temperature measuring circuit comprises a current source, a voltage measurer and a grounding end; the temperature measuring element of the temperature measuring resistor adopts a four-wire system connection method, leads out wires from two ends of one end of the temperature measuring element of the temperature measuring resistor are electrically connected with two poles of a current source, and leads out wires from the other end of the temperature measuring resistor are electrically connected with a grounding end; lead wires are led out from two ends of the temperature measuring element of the temperature measuring resistor and are electrically connected with a positive phase input end and a negative phase input end of an acquisition channel of the voltage measurer; the method comprises the steps that gating switches are respectively arranged on two wires between a temperature measuring element of a temperature measuring resistor and an input end of a voltage measurer collecting channel, and gating switches are arranged on wires between a current source and the temperature measuring element of the temperature measuring resistor or between a grounding end and the temperature measuring resistor; the at least two temperature measuring resistance temperature measuring elements use the acquisition channel of the same voltage measurer, and the signal source received by the acquisition channel of the voltage measurer is controlled by controlling the on-off of the gating switch; the gating switch is a signal relay.
And gating switches are arranged on two wires connected between the two poles of the current source and the temperature measuring element.
The temperature measuring circuit also comprises a reference resistor; the temperature measuring element is electrically connected with the two poles of the current source after being connected with the reference resistor in series; leading out wires from two ends of the temperature measuring element to be connected with one acquisition channel of the voltage measurer, and leading out wires from two ends of the reference resistor to be connected with the other acquisition channel of the voltage measurer; and calculating the resistance value of the temperature measuring element by combining the voltage at the two ends of the temperature measuring element and the voltage at the two ends of the reference resistor.
At least two temperature measuring elements are connected with the same reference resistor in series, and the temperature measuring elements which are connected with the reference resistor in series are selectively connected through a gating switch.
The wires led out from the two ends of the temperature measuring element are connected with the connector, and then are connected with the temperature measuring circuit through the extension wires; the wires led out from the two ends of the temperature measuring element are electrically connected with the extension wires through the wire connector lug on the connector; the wire connector lugs connected with the four wires led out by the same temperature measuring element are continuously coated by aluminum oxide or heat-conducting silicone grease.
The gating switch on the lead led out through the same temperature measuring element is continuously coated by alumina or heat-conducting silicone grease.
The conductor reference layers which are electrically insulated with the lead wire and the extension lead wire led out from the temperature measuring element are respectively coated outside the lead wire and the extension lead wire, the conductor reference layers coated outside the lead wire and the extension lead wire are electrically connected through the reference layer connector lug on the connector, and the conductor reference layers are electrically connected with the circuit board reference layers in the temperature measuring circuit board; the circuit board reference layer is a conductor interlayer in the circuit board, and covers the projection of the current source, the reference resistor, the voltage measurer and the wires connected with the reference resistor, the voltage measurer but is not electrically connected with the current source, the reference resistor, the voltage measurer and the wires connected with the reference resistor, the voltage measurer.
Continuously coating the reference layer lug and the wire lug with aluminum oxide or thermally conductive silicone grease; aluminum oxide or heat-conducting silicone grease is used for continuously coating four wires led out by the same temperature measuring element and a wiring terminal on a temperature measuring circuit board connected with the reference layer.
At least two temperature measuring elements are arranged at the same temperature measuring site.
A temperature measuring circuit comprises a current source, a voltage measurer, a grounding end and at least two input channels; each input channel comprises four wiring terminals, a first wiring terminal of each input channel is electrically connected with a current source, a second wiring terminal and a third wiring terminal are respectively electrically connected with a positive phase input end and a negative phase input end of one acquisition channel of the voltage measurer, and a fourth wiring terminal is electrically connected with a grounding terminal; the second wiring end and the third wiring end of at least two input channels are respectively and electrically connected with the gating switch and then are electrically connected with the positive phase input end and the negative phase input end of the same acquisition channel of the voltage measurer; the gating switch is a signal relay; the four terminals of each input channel are coated successively with alumina or thermally conductive silicone grease.
The multi-path temperature measuring device adopts a plurality of resistive temperature measuring element elements and is matched with a multi-path temperature measuring circuit to measure temperature. The temperature measuring element adopts a four-wire system connection method, so that the influence of the wire resistance on the temperature measuring precision is eliminated; the two end lead wires of at least two temperature measuring elements are connected with the same acquisition channel of the voltage measurer, signals of the temperature measuring elements acquired by the voltage measurer are controlled by using a gating switch, multiplexing of the acquisition channels of the voltage measurer is achieved, the use amount of the acquisition channels of the voltage measurer is saved, and the complexity and cost of a temperature measuring circuit are reduced; the signal relay is used as a gating switch, so that leakage current of the gating switch is eliminated, and the temperature measurement precision is improved; a gating switch is arranged on a power line of the temperature measuring element, and the current supply to the temperature measuring element is cut off when a signal is not acquired, so that the interference of the heating of the temperature measuring element and a wire on the temperature measurement is reduced; the influence of factors such as current source output current fluctuation, circuit zero drift and the like on temperature measurement precision is eliminated by using a proportional method measurement principle; the periphery of a lead wire led out from the temperature measuring element and the periphery of a lead wire extension line are coated with a conductor reference layer, the conductor reference layer of the lead wire and the lead wire extension line is electrically connected with a reference layer of a temperature measuring circuit board, noise signals in the lead wire, which are caused by impedance matching, environmental electromagnetic interference and crosstalk factors between the lead wires, are restrained, and the temperature measuring precision is improved; the two ends of the lead, the lead extension line and the conductor reference layer are respectively provided with similar or equal temperatures, and thermoelectric potential interference signals caused by unequal temperatures of the two ends of the lead are restrained; the multi-path temperature measuring device and the multi-path temperature measuring circuit used by the same realize multiplexing of the acquisition channels of the voltage measurer, reduce interference noise signals introduced by wire impedance, line-to-line crosstalk, environmental electromagnetic interference and thermoelectric effect, and improve temperature measuring precision.
Drawings
FIG. 1 is a schematic circuit diagram of a first embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of a second embodiment of the present invention;
FIG. 3 is a schematic circuit diagram of a third embodiment of the present invention;
Fig. 4 is a schematic circuit diagram of a fourth embodiment of the present invention.
Detailed Description
Example 1
A multi-path temperature measuring device according to the present invention, as shown in FIG. 1, includes a first temperature measuring element Rs1 and a second temperature measuring element Rs2; the temperature measuring element is a resistive electric element, and the resistance value of the temperature measuring element changes along with the change of temperature; the temperature measuring element may be a resistance temperature detector (RESISTANCE TEMPERATURE DETECTOR, RTD), such as a PT100 type platinum resistance or a PT1000 type platinum resistance; the temperature measuring element can also be a thermistor, such as a 5611T type thermistor manufactured by Fluke company, and the accuracy after calibration can reach 0.0001 ℃. The temperature measuring element is thermally coupled with the object to be measured, the resistance of the temperature measuring element is detected, and the temperature of the temperature measuring element and the temperature of the object to be measured can be calculated. The temperature measuring element has two-wire system, three-wire system, four-wire system and other wiring methods, and the four-wire system wiring method is used in the invention to eliminate the influence of lead resistance on the temperature measuring precision; specifically, two lead terminals 1a and 1b of the temperature measuring element are respectively connected with two poles of a current source Is through power lines 2a and 2 b; the lead terminals 1a and 1b of the temperature measuring element are also connected to the voltage measurer via measuring lines 3a and 3b, respectively. The temperature measuring element Is electrically connected with a temperature measuring circuit through a wire, the temperature measuring circuit Is arranged on the temperature measuring circuit board 7, and the temperature measuring circuit comprises a current source Is and a voltage measurer; the temperature measuring circuit provides power to the temperature measuring element and collects voltage signals from both ends of the temperature measuring element. In this embodiment the voltage measurer is an analog-to-digital conversion circuit (ADC) or an integrated circuit thereof; the current source Is supplies stable current to the temperature measuring element, the resistance value of the temperature measuring element Is calculated by detecting the voltage at two ends of the temperature measuring element, and then the corresponding temperature value Is calculated. In the actual use occasion, the distance between the temperature measuring element and the temperature measuring circuit board 7 is often longer, and four wires led out from two ends of the temperature measuring element can be respectively connected with the plug 41 on the connector 4, and are respectively connected with the wiring terminal 6 on the temperature measuring circuit board 7 through the extension wire 5 connected with the plug 41, so that the extension of the connection wire is realized.
The high-precision temperature measuring device belongs to a precision measuring device, the selected devices and design schemes have high standard and high cost, the system complexity of the temperature measuring device is expected to be as low as possible, the structure is compact, the reliability of the temperature measuring device is improved, and the cost of the temperature measuring device is reduced. In many temperature measurement occasions, temperature measurement elements are required to be arranged at a plurality of sites to perform temperature measurement, and the common practice is that one acquisition input channel of a voltage measurer in a temperature measurement circuit is used for acquiring a voltage signal corresponding to one temperature measurement element object; however, when the number of the temperature measuring elements is large, the complexity of the system is obviously increased, and the voltage measurer is one of core modules in the temperature measuring circuit, so that the cost is high, and if the number of input channels of the voltage measurer is increased, the cost of the temperature measuring circuit is obviously increased.
In this embodiment, the temperature measuring circuit further includes a gate 81 and a controller MCU, and the gate 81 includes a gate switch 8; the measuring lines 3a and 3b of the first temperature measuring element Rs1 are respectively and electrically connected with the normal phase input end AIN+ and the reverse phase input end AIN-of one acquisition channel of the ADC through a gating switch 8 on the first gating device 81a so as to control whether the voltage signal of the first temperature measuring element Rs1 is input into the input end of the ADC; the power line 2a or 2b Is electrically connected to one pole of the current source Is through a gate switch 8 on the first gate 81a to control whether to supply power to the first temperature measuring element Rs 1. Similarly, the measuring line of the second temperature measuring element Rs2 is electrically connected to the non-inverting input terminal ain+ and the inverting input terminal ain-of one acquisition channel of the ADC through the gate switch on the second gate 81 b; the power line of the second temperature measuring element Rs2 Is electrically connected with one pole of the current source Is through a gating switch on the second gating device 81 b; the measuring lines of the first temperature measuring element Rs1 and the second temperature measuring element Rs2 are connected into the same acquisition channel of the ADC after passing through the respective gating switches 8. The control port c of the controller MCU is electrically connected with the control port c of the gating switch 8 to control the on-off of each gating switch 8. When the voltage signal is acquired for the first temperature measuring element Rs1, the controller MCU sends out a signal, the connection between the measuring line of the first temperature measuring element Rs1 and the ADC is communicated, and the connection between the measuring line of the second temperature measuring element Rs2 and the ADC is disconnected; when the voltage signal is acquired to the second temperature measuring element Rs2, the controller MCU sends out a signal, the connection between the measuring line of the second temperature measuring element Rs2 and the ADC is communicated, and the connection between the measuring line of the first temperature measuring element Rs1 and the ADC is disconnected; thereby realizing multiplexing of ADC acquisition channels. When a voltage signal is not acquired for a certain temperature measuring element, a gating switch on a power line is operated to cut off current supply, so that the temperature rise of the temperature measuring element and the power line caused by heat generation of current can be reduced, the thermoelectric potential in a wire caused by a thermoelectric effect is restrained, and noise signals in the wire are reduced.
The gating switch 8 may be an analog switch or a signal relay. The analog switch is a device for realizing switch control by using a semiconductor switch tube, has no mechanical contact and small impact, but has the problems of large on resistance, poor on resistance controllability, leakage current and the like, and can reduce the precision of a temperature measuring circuit. In the present embodiment, a signal relay type of gate switch 8 is used, preferably a reed switch (reed switch) type of gate switch 8; the signal relay adopts the contact of a mechanical contact or the on-off of a switching control circuit, so that the problem of leakage current does not exist. The high-sensitivity reed switch produced by TE company can be selected as the gating switch 8, so that the switch switching time smaller than 2ms is realized; the switch switching time length and the electric signal impact problem caused by the switch switching are acceptable for the temperature measurement process with large inertia, and the requirement of temperature measurement precision of better than 0.001 ℃ can be met.
It can be understood that the temperature measuring circuit is not only limited to multiplexing the voltage acquisition channels of two temperature measuring elements, but also can be suitable for multiplexing the voltage acquisition channels of more than two temperature measuring elements after simple analogizing expansion.
Example two
As shown in fig. 2, in order to improve the accuracy of the temperature measuring circuit, the resistance value of the temperature measuring element is measured and calculated by a proportional method in the present embodiment. Specifically, a reference resistor Rref Is connected in series between a temperature measuring element and a current source Is, and leads are led out from two ends of the reference resistor Rref and connected into an ADC (analog to digital converter) to detect the voltage of two ends of the reference resistor Rref; the reference resistor Rref is a high-precision resistor with a determined resistance value, and the resistance value of the reference resistor Rref can be selected to be equal to the resistance value of the temperature measuring element so as to fully utilize the voltage acquisition range of the ADC; placing the reference resistor Rref in a temperature stable environment; the ADC respectively collects the voltages at the two ends of the temperature measuring element and the reference resistor Rref, and the actual resistance value of the temperature measuring element can be calculated according to the fact that the voltages at the two ends of the temperature measuring element and the reference resistor Rref are in direct proportion to the resistance values of the temperature measuring element and the reference resistor Rref. The actual resistance value of the temperature measuring element is measured by adopting a proportional method, so that resistance measurement errors caused by current fluctuation output by the constant current source can be eliminated, and measurement errors caused by circuit zero drift and temperature drift can be eliminated. The plurality of temperature measuring elements can share a reference resistor Rref, and the serial connection relation between each temperature measuring element and the reference resistor Rref is controlled by the gating switch 8.
In order to maintain the symmetry of the wires connected with the temperature measuring element, the symmetry of the impedance and the heating characteristic of the wires Is specifically included to inhibit noise caused by the asymmetry of the impedance and the heating characteristic in the temperature measuring circuit, the gating switch 8 Is arranged in the wires connected with the two poles of the current source Is of the temperature measuring element, so that the impedance and the heating characteristic on the power wire of the temperature measuring element are symmetrical, and the cancellation and inhibition of noise signals in the wires are facilitated.
Preferably, four wires led out from two ends of the same temperature measuring element are respectively connected to four wire lugs 41 on the same connector 4; more preferably, the four wire connector lugs 41 are well thermally coupled, and particularly, good heat conducting materials such as aluminum oxide or heat conducting silicone grease can be used for continuous coating, or the connector 4 adopts a metal packaging structure, so that the temperatures on the four wire connector lugs 41 are close to or equal to each other; and, good geothermal coupling is provided between the gating switches 8 on the wires connected with the same temperature measuring element and the voltage measurer, more preferably good geothermal coupling is provided between the gating switches 8 connected with four wires of the same temperature measuring element, in particular, the four gating switches 8 can be arranged in the same gating device 81, and the four gating switches 8 are continuously coated by using good heat conducting materials such as alumina or heat conducting silicone grease, or the gating device 81 adopts a metal packaging structure, so that the temperatures of the four gating switches 8 are close to or equal to each other. The temperature measuring circuit board 7 is arranged in a temperature stable environment, and particularly ensures that the temperature of the wiring terminals 6 connected with four wires of the same temperature measuring element Rs is equal. By the arrangement, the two ends of the power line, the measuring line and the extension wire have basically equal temperature respectively, and as the power line, the measuring line and the extension wire are arranged in pairs, and the current directions in the wires arranged in pairs are opposite, the temperatures at the two ends of the paired wires are respectively equal, and the thermoelectric interference signals generated by thermoelectric effect in the wires can be counteracted and eliminated, so that the temperature measurement precision is improved.
The rest of the embodiments are the same as in example one.
Example III
In many temperature measurement occasions, the setting position of the temperature measurement element is far away from the signal acquisition device such as ADC, and the length of a wire between the temperature measurement element and the temperature measurement circuit board 7 is long, and the electrical property of the wire can influence the temperature measurement precision: the mismatch between the impedance of the wire and the impedance of the upstream and downstream conductors can cause the signal to oscillate in the wire; crosstalk noise can be introduced between two wires with similar positions due to mutual inductance and mutual capacitance; the impedance instability between the wire and the environment causes noise and the like to be introduced into the transmitted signal. In this embodiment, in order to suppress noise introduced by the impedance factor of the wires, an insulating layer is coated outside the power lines 2a and 2b and the measuring lines 3a and 3b, and a conductor layer is coated outside the insulating layer, where the conductor layer may be in a structural form of a metal woven mesh, and may play a role in shielding electromagnetic signal interference of the environment; the power lines 2a, 2b and the outer coated conductor layers of the measuring lines 3a, 3b are electrically connected together to form isoelectric points, which are marked as lead reference layers 81 in fig. 1. Similarly, the insulating layer is coated on the outer part of the extension wire 5, and the conductor layer is coated on the outer part of the insulating layer again to play a role of shielding signal interference, so that the conductor layers on the outer parts of the four extension wires 5 are electrically connected together to form equipotential points, which are marked as an extension wire reference layer 82 in fig. 1; the electrical connection between the lead reference layer 81 and the extended lead reference layer 82 via the reference layer connector lug 42 on the connector assembly 4 comprises a circuit board reference layer 71 comprising a conductor interlayer, wherein the circuit board reference layer 71 covers the current source Is, the reference resistor Rref, the ADC and the projection of the leads connected thereto on the circuit board but Is not electrically connected with the current source Is, the reference resistor Rref, the ADC and the leads connected thereto; noise signals in the wires on the temperature measuring circuit board 7 are connected in an electromagnetic induction mode; the extension lead reference layer 82 is electrically connected to the circuit board reference layer 71 via the reference layer connection terminal 61. Through the above-described electrical connection structure, the lead reference layer 81, the extension lead reference layer 82, and the circuit board reference layer 71 form an equipotential reference layer; the lead wire, the extension wire of the temperature measuring element Rs and the wire on the temperature measuring circuit board 7 have relatively stable and relatively small impedance with the equipotential reference layer, noise signals generated by the environmental interference, the line-to-line crosstalk and other factors in the wire tend to propagate into the equipotential reference layer and consume the lapse of the noise signals, which is favorable for inhibiting the noise signals in the temperature measuring circuit and improving the temperature measuring precision. Therefore, the electric connection structure of the invention suppresses noise signals in the temperature measuring circuit and improves the measuring precision of the temperature measuring device.
Preferably, the temperature measuring circuit comprises a grounding end GND, and one pole of the current source is electrically connected with the temperature measuring element Rs and the reference resistor Rref through a lead and then is electrically connected with the grounding end GND; the circuit board reference layer 71 is electrically connected to the ground GND via the reference layer connection terminal 61 and the extended wire. The equipotential reference layer formed by the lead reference layer 81, the extension lead reference layer 82 and the circuit board reference layer 71 is electrically connected with the ground terminal, so that the impedance of the equipotential reference layer is more stable, and the suppression effect on noise signals in the temperature measuring circuit is improved.
Preferably, the reference layer connector lug 42 is provided with four wire connector lugs 41 connected with four wires led out from the same temperature measuring element, positioned on the same connector 4, and well thermally coupled with the four wire connector lugs 41; the four wires led out by the same temperature measuring element are well thermally coupled with the wiring terminal 6 on the temperature measuring circuit board 7 connected with the reference layer; the temperature of each lug and each wiring terminal are basically equal, so that the thermoelectric potential interference signals introduced by the thermoelectric effect are restrained. The method for making the wire connector or the wire connector have good thermal coupling can be to use a temperature control container with a temperature regulator to accommodate the connector 4 or the temperature measuring circuit board 7, can use a metal structure to encapsulate the connector 4, can use good thermal conductors such as alumina or heat conduction silicone grease to continuously coat the wire connector 41 and the reference layer connector 42 or the wire connector 6. The rest of the embodiments are the same as the first embodiment or the second embodiment.
Example IV
As shown in fig. 4, at least two temperature measuring elements are disposed on the same temperature measuring site 13, and the two temperature measuring elements are used to measure the temperature of the same temperature measuring site, so that the measurement results of the two temperature measuring elements can be mutually checked, and the reliability of the measurement results is improved. The two temperature measuring elements adopt the same voltage acquisition channel of the temperature measuring circuit to measure voltage; the channel number of the voltage measurer can be reduced, and the complexity and cost of the temperature measuring circuit are reduced. The two temperature measuring elements are provided with the temperature measuring circuit by adopting a proportional method, and the same reference resistor Rref is used, so that the consistency of temperature measuring circuit devices connected with the two temperature measuring elements can be improved, and the temperature measuring precision is improved.
Preferably, the connectors 4 to which two or more temperature measuring elements of the same temperature measuring site are connected are thermally well coupled, for example, two or more connectors 4 are placed in the same thermal container 43 so that the temperatures on the respective wire lugs 41 are substantially equalized; the gates 81 connected with two or more temperature measuring elements Rs of the same temperature measuring site are well thermally coupled, for example, the two or more gates 81 are shielded and packaged by using the same metal cover, so that the temperatures of the gating switches 8 are basically equal; the two ends of the power line, the measuring line and the corresponding extension lead led out by the temperature measuring element have basically equal temperature, thereby inhibiting the thermoelectric interference signal led in by the thermoelectric effect.
The rest of the embodiments are the same as any one of the first to third embodiments.
The foregoing and construction describes the basic principles, principal features and advantages of the present invention product, as will be appreciated by those skilled in the art. The foregoing examples and description are provided to illustrate the principles of the invention and to provide various changes and modifications without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (7)
1. A multichannel temperature measuring device, its characterized in that: comprises a temperature measuring circuit and at least two temperature measuring elements; the temperature measuring element is a resistive electric element, and the resistance value of the temperature measuring element changes along with the change of temperature; the temperature measuring circuit comprises a current source and a voltage measurer; the temperature measuring element adopts a four-wire system connection method, and leads are led out from two ends of the temperature measuring element and are electrically connected with two poles of a current source; lead wires are led out from two ends of the temperature measuring element and are electrically connected with a positive phase input end and a negative phase input end of an acquisition channel of the voltage measurer; the method comprises the steps that gating switches are respectively arranged on two wires between a temperature measuring element and an input end of a voltage measurer acquisition channel, and gating switches are arranged on wires between a current source and the temperature measuring element; the at least two temperature measuring elements use the acquisition channel of the same voltage measurer, and the signal source received by the acquisition channel of the voltage measurer is controlled by controlling the on-off of the gating switch; the gating switch is a signal relay; a gating switch is arranged on two wires connected between the two poles of the current source and the temperature measuring element;
Four gating switches connected with the same temperature measuring element are arranged in the same gating device, and the gating device adopts a metal packaging structure, or aluminum oxide or heat-conducting silicone grease is used for continuously coating gating switches on leads led out from the same temperature measuring element;
the wires led out from the two ends of the temperature measuring element are connected with the connector, and then are connected with the temperature measuring circuit through the extension wires; the wires led out from the two ends of the temperature measuring element are electrically connected with the extension wires through the wire connector lug on the connector; the wire connector lugs connected with the four wires led out by the same temperature measuring element are continuously coated by aluminum oxide or heat-conducting silicone grease.
2. The multi-path temperature measurement device of claim 1, wherein: the temperature measuring circuit also comprises a reference resistor; the temperature measuring element is electrically connected with the two poles of the current source after being connected with the reference resistor in series; leading out wires from two ends of the temperature measuring element to be connected with one acquisition channel of the voltage measurer, and leading out wires from two ends of the reference resistor to be connected with the other acquisition channel of the voltage measurer; and calculating the resistance value of the temperature measuring element by combining the voltage at the two ends of the temperature measuring element and the voltage at the two ends of the reference resistor.
3. The multi-path temperature measurement device of claim 2, wherein: at least two temperature measuring elements are connected with the same reference resistor in series, and the temperature measuring elements which are connected with the reference resistor in series are selectively connected through a gating switch.
4. The multi-path temperature measurement device of claim 1, wherein: the conductor reference layers which are electrically insulated with the lead wire and the extension lead wire led out from the temperature measuring element are respectively coated outside the lead wire and the extension lead wire, the conductor reference layers coated outside the lead wire and the extension lead wire are electrically connected through the reference layer connector lug on the connector, and the conductor reference layers are electrically connected with the circuit board reference layers in the temperature measuring circuit board; the circuit board reference layer is a conductor interlayer in the circuit board, and covers the projection of the current source, the reference resistor, the voltage measurer and the wires connected with the reference resistor, the voltage measurer but is not electrically connected with the current source, the reference resistor, the voltage measurer and the wires connected with the reference resistor, the voltage measurer.
5. The multi-path temperature measurement device of claim 4, wherein: continuously coating the reference layer lug and the wire lug with aluminum oxide or thermally conductive silicone grease; aluminum oxide or heat-conducting silicone grease is used for continuously coating wiring terminals on a temperature measuring circuit board connected with four wires led out by the same temperature measuring element and a reference layer.
6. The multi-path temperature measurement device of claim 1, wherein: at least two temperature measuring elements are arranged at the same temperature measuring site.
7. A temperature measurement circuit as claimed in any one of claims 1 to 6, wherein: the device comprises a current source, a voltage measurer, a grounding end and at least two input channels; each input channel comprises four wiring terminals, a first wiring terminal of each input channel is electrically connected with one pole of the current source, a second wiring terminal and a third wiring terminal are respectively electrically connected with the positive phase input end and the negative phase input end of one acquisition channel of the voltage measurer, and a fourth wiring terminal is electrically connected with the other pole of the current source; the second wiring end and the third wiring end of at least two input channels are respectively and electrically connected with the gating switch and then are electrically connected with the positive phase input end and the negative phase input end of the same acquisition channel of the voltage measurer; the gating switch is a signal relay; the four terminals of each input channel are coated successively with alumina or thermally conductive silicone grease.
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Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105092075A (en) * | 2015-05-25 | 2015-11-25 | 山东航天电子技术研究所 | High accuracy multi-channel temperature signal acquisition device |
| CN210862965U (en) * | 2019-12-10 | 2020-06-26 | 湖南优利泰克自动化系统有限公司 | Temperature acquisition device |
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| KR101074599B1 (en) * | 2008-12-31 | 2011-10-17 | 엘에스산전 주식회사 | Temperature Detector and Measurement Method Of The Same |
| CN103791944B (en) * | 2012-11-02 | 2016-12-21 | 上海微电子装备有限公司 | A kind of high-accuracy general measurement apparatus |
| CN106569525B (en) * | 2016-10-28 | 2018-11-23 | 北京航天控制仪器研究所 | A kind of digital constant temperature control circuit applied to moving base gravimeter |
| CN206671127U (en) * | 2017-03-23 | 2017-11-24 | 中国第一汽车股份有限公司 | A kind of automobile-used particulate matter sensors chip |
| CN108736824A (en) * | 2018-06-14 | 2018-11-02 | 合肥流明新能源科技有限公司 | A kind of fault detect cooling photovoltaic cell junction box |
| CN109738087B (en) * | 2019-03-07 | 2023-12-19 | 深圳市拓普瑞电子有限公司 | Multichannel three-wire system thermal resistance measuring system and method |
| CN110718341A (en) * | 2019-10-18 | 2020-01-21 | 江苏弘银合金科技有限公司 | Method for manufacturing adjustable insulation layer of surface resistance of conducting wire |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN105092075A (en) * | 2015-05-25 | 2015-11-25 | 山东航天电子技术研究所 | High accuracy multi-channel temperature signal acquisition device |
| CN210862965U (en) * | 2019-12-10 | 2020-06-26 | 湖南优利泰克自动化系统有限公司 | Temperature acquisition device |
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