SU1286911A1 - Device for measuring temperature - Google Patents

Description

12

keys to the control input of the sixth key, as well as to the first inputs of the fifth, sixth and second inputs of the first elements AND of each measuring channel; the first and second outputs of the control unit are connected respectively to the second inputs of the fifth and sixth elements AND of each measuring channel, The third, third and fifth outputs of the control unit are connected respectively to the third, fourth and fifth inputs of the analyzer and to the second inputs of the fourth, seventh And elements of each measuring channel and the second the input of the third element I, the output of which is connected to the control input of the fifth key, as well as the second input of the second element I of each measuring channel, the sixth output of the control unit. is connected to the sixth input of the analyzer and the single inputs of the decoder, the information inputs of which are connected to the information output the control unit, and the output of the decoder is connected to the indicator, the seventh output of the control unit is connected to the seventh input of the analyzer, and the third inputs of the fourth, fifth, sixth and seventh elements AND and the first input of the first The first element AND of each measuring channel is connected to the corresponding output of the control unit.

2. A device according to claim 1, characterized in that the analyzer is made up of nine AND elements, eight flip-flops and five signaling devices, the first inputs of the first, second and third elements AND are connected and are the first input bus, and the first input of the fourth element AND

one

is the second input bus, the second inputs of the first and second elements I are the third and fourth input buses respectively, and the second input of the third element I is connected to the inputs of the zero, fourth, fifth, sixth, seventh and eighth triggers and is the fifth input bus, the outputs of the first, second and third elements AND are connected respectively to the installation inputs of the first, second and third triggers, the second input of the fourth element I is the sixth input bus, and its output by It is connected to the first inputs of the fifth, sixth, seventh, eighth, and ninth elements, and the direct output of the first trigger is connected to the second inputs of the sixth and seventh elements, and the inverse output of the first trigger is connected to the second inputs of the fifth, eighth, and nine In addition, the direct output of the second trigger is connected to the third inputs of the fifth and seventh elements, and the inverse output of the second trigger is connected to the third inputs of the sixth, eighth and ninth elements of I, the direct output of the third trigger is connected to the fourth inputs of the third first, sixth and ninth elements And, and the inverse output of the third trigger is connected to the fourth inputs of the seventh and eighth elements And, the outputs of the fifth, sixth, seventh, eighth and ninth elements And connected to the inputs of the unit in a single fourth state, n additionally, the sixth, seventh, and eighth triggers, the outputs of which are connected. To signaling devices.

one

The invention relates to devices for measuring the temperature of resistance thermocouples.

The purpose of the invention is to increase the reliability of the measurement information by ensuring the integrity of all measurement targets is monitored.

Figure 1 shows the functional diagram of the device;

figure 2 is a functional diagram of the analyzer; FIG. 3 shows timing charts of the signals at the outputs of the control unit; Fig. 4 is a table of a set of voltages across a resistor corresponding to an open circuit.

The device contains a measurement unit 1, two current sources 2 and 3, a control unit 4, an inverter 5, a deshi312

6 ftor, indicator 7, three keys 8-10, p; i3HCTop 11, bus. 12 control units, an element I, 13, an analyzer 14 and five signaling devices 15–19, as well as a thermometer 20 of resistance with lines 21–24 of communication, three keys 25–27, three elements RSHI 28–30 and six elements I 31 - 36, constituting one measuring channel 37, which in the device can be

The device works as follows.

In the measurement mode, the signal O is supplied to the bus 12 of the installation. With this, the switch 8 is closed, connecting the current source 2 to the measurement channels. On the signal of the control unit 4, the thermometers 20 are alternately connected with keys 25–27, which are controlled through the elements OR 28–30 and elements 32–35, in each measuring channel from outputs 38 and 39, and also from the additional outputs 40 of the control unit, the number of which corresponds to the number of measuring channels 37 (each output is connected to the corresponding measuring channel). In this case, the thermometer 20 is connected to measurement unit 1 via key 26, and the measurement process consists of two steps: in the first cycle, a sensor output connected to a common point is connected to current source 2 via key 27, and : 25 is another terminal connected to the measurement unit, as a result of which the following voltages are formed at the input of the measurement unit:

Ui

 I

h

UT I (Rg n- g) where Uj. - first tact voltage

measurements;

Uj - second cycle voltage

measurements;

, g - resistance of the line connecting the sensors to the common point;

RO is sensor resistance. The measure of the measured value is the voltage difference represented by the formula

di Uj - UT ip.j.

in the Control mode, the signal 1 is sent to the installation bus 12.

14

through the key-9, the current source 3 is connected to the measurement channels and elements 31, 34 and 13 are opened for passing from the control pulse control unit 4 (from outputs 41 to 43) and alternately closing the keys 25 -.27 and 10. As a result the current HCTO4HHka 3 of the current flows alternately through all the studied connection circuits and, if it is in good condition, creates a voltage drop across the resistor 11; the absence of voltage on it at the time of passing the control pulse indicates a circuit failure.

An open circuit is determined by the combination of the voltages obtained in a resistor 11 according to the table (Fig. 4) for the control cycle. The control cycle consists of three cycles.

In the Tm cycle, the signal from the output 41 of the control unit 4 closes the key 25 and the current flows through the circuit from the current source 3: key 9, key 25, line 21, thermometer 20, line 24, common point, resistor 11. If line 21 thermometer 20 or line 24 - in the break on the resistor 11 there is no voltage O, and if all of these elements are intact, there is 1 on the resistor 11.

In the 11th cycle, the signal from the output 42 of the control unit 4 closes the keys 26 and 10 and the current from source 3 flows through the circuit: key 10, key 26, line 22, thermometer 20, line 24, common point, resistor 11. If any - either of the elements 22, 20, 24 will be in the cliff, O is present on the resistor 11

In the 111th cycle, the signal from the output 43 of the control unit 4 closes the key 27 and the current from source 3 flows through the circuit: key 9, key 27, line 23, line 24, common point, resistor 11. If one of the lines 23 and 24 will be in the open circuit, at the output of the resistor 11 O is present. The open circuit is determined from the table (figure 4).

The integrity analysis of the circuits is carried out automatically in the analysis block 14, which consists (Fig. 2) Of the four two-input circuits 46-49, eight triggers 50-57 and five four-input circuits AND 58-62. The first inputs of elements 59 and 60 are connected to the direct output of trigger 50, and its reverse output is connected to the first

FIG. 2

Fig.Z

Sending but //

FIG.

Claims (2)

(34) 1. TEMPERATURE MEASUREMENT DEVICE, comprising a measuring unit, a control unit, a first current source, an inverter, and also in each measuring channel a resistance thermometer, first and second elements AND, first, second and third switches, and the first conclusions of the first and the second keys are connected respectively through the first and second communication lines to the first output of the resistance thermometer, the second output of which through the third and fourth lines, respectively, is connected to the first output of the third key and the common bus, the second conclusions of the first and third of the keys are interconnected, and the first input of the measurement unit is connected to the second terminals of the second key of each measuring channel, while the second input of the measurement unit and one pole of the first current source are connected to the common bus, and the first inputs of the first and second element And are interconnected, characterized in that, in order to increase the reliability of the measurement information by providing integrity control of the measuring circuits, the installation bus is introduced into it Control, resistor, analyzer, decoder with indicator, second current source connected to the first input of the analyzer and through a resistor with a common bus, fourth, fifth and sixth switches, third element And, as well as fourth, fifth in each measuring channel, ' the sixth and seventh elements AND and the first, second and third elements OR, and the outputs of the first, second and third elements OR are connected respectively to the control inputs of the first, second and third keys, and the outputs of the fourth and fifth elements AND are connected to the inputs of the first of the first OR element, the outputs of the sixth and seventh elements AND are connected to the inputs of the third OR element, the outputs of the first and second elements AND are connected to the inputs of the second OR element, and the first inputs of the fourth and seventh elements AND of each measuring channel are connected to the Control bus, which is also connected the first input of the third element And, the inverter input, the control input of the fourth key and the second input of the analyzer, the second pole of the second current source is connected to the first output of the fourth key, and the second output of the fourth key is Inonii with second terminals of the first switch of each measuring channel, and first terminals of the fifth and sixth keys, the second terminal of the fifth switch is connected to the first input of the measurement unit, the second output of the sixth switch coupled to a second pole of the first current source, the output of inverter sub SU „„ 1286911 keys to the control input of the sixth key, as well as to the first inputs of the fifth, sixth and second input of the first elements AND of each measuring channel, while the first and second outputs of the control unit are connected respectively to the second inputs of the fifth and sixth elements And of each measuring channel and the third, fourth and fifth outputs of the control unit are connected respectively to the third, fourth and fifth inputs of the analyzer and to the second inputs of the fourth, seventh elements of each measuring channel and W, respectively the third input of the third element And, whose output is connected to the control input of the fifth key, as well as the second input of the second element And of each measuring channel, the sixth output of the control unit is connected to the sixth input of the analyzer and the input inputs of the decoder, the information inputs of which are connected to the information output of the control unit and the decoder output is connected to the indicator, the seventh output of the control unit is connected to the seventh input of the analyzer, and the third inputs of the fourth, fifth, sixth and seventh elements And and the first input the first- element and each measuring channel connected to a corresponding output of the control unit. 2. The device according to claim 1, characterized in that the analyzer is made in the form of nine And elements, eight triggers and five signaling devices, the first inputs of the first, second and third elements And are connected and are the first input bus, and the first input of the fourth element And is the second input bus, the second inputs of the first and second elements And are respectively the third and fourth input buses, and the second input of the third element And is connected to the inputs of the zero state of the fourth, fifth, sixth, seventh and eighth triggers and is the fifth input bus, the outputs of the first, second, and third AND elements are connected respectively to the unit inputs of the first, second, and third triggers, the second input of the fourth AND element is the sixth input bus, and its output is connected to the first inputs of the fifth, sixth, seventh , the eighth and ninth elements And, while the direct output of the first trigger is connected to the second inputs of the sixth and seventh elements And, and the inverse output of the first trigger is connected to the second inputs of the fifth, eighth and ninth elements And, pr my output of the second trigger is connected to the third inputs of the fifth and seventh elements And, and the inverse output of the second trigger is connected to the third inputs of the sixth, eighth and ninth elements And, the direct output of the third trigger is connected to the fourth inputs of the fifth, sixth and ninth elements And, and the inverse the output of the third trigger is connected to the fourth inputs of the seventh and eighth elements And, the outputs of the fifth, sixth, seventh, eighth and ninth elements And are connected respectively to the inputs of the installation in a single state of the fourth, fifth, estogo, seventh and eighth flip-flops, the outputs of which podklyucheny.k signaler.