SU901840A2 - Pneumatic device for measuring temperature - Google Patents

Description

(54) PNEUMATIC DEVICE FOR TEMPERATURE MEASUREMENT

one

The image is relative to pneumatic temperature measuring devices.

According to the main author. St. N 678333 a pneumatic device, a societal sensitive element, is known, and a fermentation amplifier, a stabilized power source, to which two parallel pivomors are connected, a secondary device and a resistor, which is connected to the output of one of the resistors, and to one of the inputs of the differential amplifier, sensitive element and the output of another pneumatic resistance 1

The disadvantages of the known device are the inadequate measurement accuracy and the inability to adjust ranges.

The purpose of the invention is to increase the accuracy, measurement and provision of adjustable ranges.

The goal is achieved by the fact that a nonlinear element is introduced into the pneumatic device for temperature measurement, one input of which is connected to the output of one of the pneumatic resistances and the input of the trimming pneumatic resistance, the other input is connected to the input of the sensitive element and the output of the other pneumatic resistance, and the inputs of the nonlinear element are connected to the inputs differential usi / mtel and communicated with the atmosphere.

FIG. 1 is a block diagram of a pneumatic device for measuring temperature; FIG. 2 - nonlinear element, section.

Claims (2)

The pneumatic device for temperature measurement contains a sensing element I, a differential amplifier 2, a non-linear element 3, a secondary device 4, a drag resistor 5 and 6, a trimming pneumatic resistance 7, a stabilized power supply 8 and connecting channels 9-22. Nonlinear 390 element 3 consists of housings 23 and 24. The interfacial membrane 25, which forms chambers 26 and 27, is interposed. On the membrane 25 there is a flap 28. On the casing 23 there is an entrance 29 connected to the channel 16, a 30, connected to the channel 18 and a nozzle 31 connected to the atmosphere. On the housing 24 there are inlets 32 and outlet 33, respectively connected to channels 13 and 19, and a nozzle 34 connected to the atmosphere. The 8-power supply, connected with channel 9, which branches into channels 10, 11-22, respectively, to the pneumatic resistance inputs 5, the differential amplifier power input 2 and the electrical resistance voltage input 6, and the pneumatic resistance output 6 is connected to one of the non-linear outputs element 3 and simultaneously channel 17 with the input of trimming pneumatic resistance 7, and the second inlet of the nonlinear element 3 is connected via channels 13 and 12 with the output of pneumatic resistance 5 and simultaneously channel 14 with the input of the sensitive element a 1. The outputs of the nonlinear element 3 through nozzles 31 and 34 are connected to the atmosphere, and channels 18 and 19 are connected to the input of a differential amplifier 2, whose outputs are connected to channels 2O and 21 with a secondary device 4, for example a differential pressure gauge. When power supply 8 is connected in channels 9, 10, II to 22, an overpressure occurs, which through a pneumatic valve in channel 6 through channels 15-17 is transmitted to input 29 of nonlinear element 3 and to input of trimming pneumatic axis against flax and 7, and through the resistance 5 through channels 12 - 14 it is fed to the input 32 of the nonlinear element 3 and to the input of the temperature-sensitive element 1. At the same time, the compressed gas is fed to the input of the power supply of the differential amplifier 2 and the outputs 20 and 21 of the S5 have an excess pressure that goes to the secondary device 4 With help The adjusting pneumatic resistance 7 establishes an overpressure corresponding to the starting point of the scale, and during the adjustment it is necessary that the nozzle 31 does not communicate with the atmosphere. When the temperature of the measured slice changes, the overload of the sensitive element 1 causes the overpressure in the channels 12-14, which is transmitted to the chamber 27 through the input 32 of the nonlinear element 3, simultaneously communicating with the atmosphere through the nozzle 34 through the output 33 and the channel 19 to the differential input booster 2. As the temperature increases, the pressure in the chamber 27 and the elastic membrane 25 rises, the nozzles 34 and 31 gradually overlap with the flap 28. As the nozzles 34 and 31 overlap, the pressure in the chambers 26 and 27 gradually increases, respectively, through channels 18 and 19 is supplied to the differential inputs the amplifier 2 and is fixed by the secondary measuring device 4. The moment of closing the nozzles 31 and 34 corresponds to the beginning of the measurement range. The proposed device provides adjustment of ranges, when it is necessary to carry out measurements not from zero, but from a certain point, for example, it is necessary to measure the temperature from 50 ° C to 2 ° C, i.e. provides temperature measurement. starting from any point in this interval up to 2OOO С, since zero is suppressed in the device. This allows you to increase the working part of the scale of the secondary device, which leads to an increase in measurement accuracy. Claims Pneumatic device for measuring temperature according to the ed. St. N "678333, characterized in that, in order to increase the ACCURACY of the measurement and provide the ability to adjust the ranges, a nonlinear element is introduced in it, one input of which is connected to the output of one of the pneumatic resistances and the input of the subtraining pneumatic resistance, the other input to the input of the sensitive element and the output of the other pneumatic resistances and the outputs of the non-linear element are connected to the inputs of the differential amplifier and communicated with the atmosphere. Sources of information taken into account in the examination I. The author's certificate of the USSR N 678333, cl. G01 C 5/28, 1977. 17 W rrVL (Rig. / 23