SU1702198A1 - Pressure pickup - Google Patents

Abstract

The invention relates to a measurement technique, in particular to capacitive pressure sensors, and can bit 1, used to measure the static and dynamic pressures of liquid and gaseous media. The purpose of the invention is to improve measurement accuracy and reliability. The goal is achieved by the fact that in a pressure sensor containing a sealed housing 1, a membrane 2 and a strain transducer, the latter is made in the form of main and additional reference and measuring capacitors, the electrodes of which have the same semi-rings symmetrical with respect to the diameter of the membrane, while the electrodes of the main and additional reference the capacitors are placed on the peripheral parts of the membrane 2, and the electrodes of the main and additional measuring capacitors are each made in the form of two electr cally connected half-rings with variable radii yl 2

Description

The invention relates to a measurement technique, in particular, sensors with capacitive transducers.

The purpose of the invention is to improve accuracy by reducing the non-linearity of the output characteristic and improving reliability by introducing / performing measurement kenam.

FIG. 1 shows the pressure sensor, a general view; in fig. 9. - section A - A in fig. one.

The pressure sensor includes a housing 1, a membrane 2 with a thickened peripheral non-deformable section 3 and a base 4, which are made in one piece, and a plate 5 attached to section 3, installed with a predetermined clearance relative to the membrane, the value of which is set at the expense of charts 6. On the surfaces of the memorials 2 and the plate 5 are made in a mirror-symmetric display in the form of semirings electrodes of the reference core 7 and additionally

8 capacitors, as well as measuring electrodes- CK; eribHCiro main 9 and an additional 10 capacitors.

Pressure sensor works as follows

By supplying the measured pressure P to the membrane 2, it deflects and the relative displacement of the electrodes of the capacitors 9 and 10 by the value X. As a result, the distance between the electrodes of the main 9 and additional 10 measuring capacitors changes (decreases) ) Capacities of measuring coders; correspond vonno to the values of A C. ° and AU and become equal to

(/

WITH

h about

g g

SIZ m th / O

 lll if-ch-.1- and-m

about

IlM +

Ad

AU,

where LSh ° and Lxx is the change in capacitance from the replacement of the pressure of P OLHOHI TO and add, the total measure- ment ––––––––––––––––

. n-ipy / 1 and each internal pa, and Rn are each the same

Сim em ° and Л С ,, i-zm - initial values of the capacities of the main and additional measuring capacitors;

Ci meas. H. The measurement is the current value of the balance of the main and complementary terminator.

Electrodes of basic measuring

 ondens. iora and AND consisting of two

Yul u and

diusnmi g |

S-LH: cT p l, 1a:. | AND, GO) OF LNIHMAL DEFINITION / OU C h u r, C. li TROR 10, BY CONDITION V13

   (, iy the same radii q, g-h, and P 1, in Ledovatons, PI membrane deflection i in m and. pressure-niq system on schmeiiigil b ij H / iencaropax (as mainly tlch and D g, pl.; glyum ) having the same GO Ii: U 1 LTGZHTRODOV (Si meas

  ), o / dm and the same change in the capacitances L, ACS) This means that the current 1mcci of the main and additional deadly capacitors has one ipyio value for any changes in pressure; .-i / GoodSchem0 S | iso So such a uopajOM is sufficient for asi-h metrological convergence. 1g- / apt: trrmsgik main and doped-n11temoe g :: m inoo

C ,, f,

gz-

111

WITH

g%

 - -g1 1 (Px)

I 1

about

H & LH

NIZM / J 1-413M

about

 I ASI1m

 -t-: LS stage

 Setr / Gn - Oiaphenip capacitances of the main 7 semi-positive8 capacitors .e

Panni cioo Stal0 and Setal provide- with the symmetry of the electrodes, having equal radii of half rings m and TBH

In order to increase the measurement accuracy by reducing the nonlinearity of the output signal, the electropods of the measuring 1 ondeno toror are made in the form of potulators and are removed from the center of the membrane, which has the largest deflection radius during late pressure.

Consequently, in the proposed construction, the nonlinearity is reduced due to the use of the curvature of the measuring electrodes, and, therefore, the exact measurement point is increased. In the capacitance converter to the output voltage, the output signal changes in the main channel of the proportional ogmsheng (Px ). and with DOP O L N THA L 1 N Or I

canape

 L X -p g5- (|) Stan

trace; elsh1, proportional to the measured dvlgii: o

The capacitive transducer conversion function for the control system can be represented as follows:

- C ° - U ° Px

M 7) b

with it, and the pressure of pressure Px is transformed into a membrane and relative deformation e, which causes relatively: displacement of X of the central part of the membrane, as a result of even change of PMSPS, 3 ° C and C of the primary and secondary / pmarite; the current value changes from top to bottom on Uc from Uc output

5 signal CHonnoni n additional channels.

The secondary sensor has high accuracy and reliability due to the maintenance of a doping measurement channel and an optimal combination of the topology of the measuring electrodes and the reference capacitor.

Cb) pmu l and z o 6 ps about the pressure sensor, which contains a hermetic case, a housing, a membrane, a plate installed with gaps relative to the membrane, and a capacitance deformation converter. made in the form of the main reference and disputable meter

0 capacitors with zrkppnr symmetric electrodes, gasplugs-coaxial co- ve-C1venno on porfrmypnyh and central parts of the membrane and plate so tl and h and yu and with the fact that, i:

5 accuracy for non-linearity yMes-Lc-fni output l-Eractor 1 mon and high reliability, the capacitive deformation transducer is equipped with an additional reference and additional measurement of the compensator. The chopsticks are arranged in the same way as the electrodes of the ibix i capacitor, and the reference electrodes have the same semicircle shape and the electrodes i / serpentry condensate 4Topv5) IMRYUT have the same shape, each of two electrically connected glands are made. different radii and each i-luko / i.zo is located symmetrically with the diameter of the memboane, but the half ring with the larger

0 with the radius of the main measuring capacitor and the semiring with nei i, IM radius of the additional mzm | r i olm condensate; us n. vn; ibor ps. of the central jaws of MGLH / 1 (, and the floor of 5 is a ridge with a smaller sigma of i3Me.ni/ of the strong K04y-i, c-Hi.a, oij, i, nth

WITH YOUR RADIUS OF ADDITION ll jro Condensing); on;

/

/

/

 And TU ////// 7 // X // V //// f //////.

at

Claims (1)

Claim A pressure sensor comprising a sealed housing, an elastic membrane, a plate mounted with a gap relative to the membrane, and a capacitive strain transducer. made in the form of a main reference and main measuring capacitors with mirror-symmetric electrodes located respectively on the peripheral and central parts of the membrane and plate, and ιοιτ: and the fact that. in order to improve accuracy by reducing the non-linearity of the output characteristic and improving reliability, the capacitive strain transducer is equipped with an additional reference and additional measuring capacitors, the electrodes of which are located similarly to the electrodes of the main capacitors, the electrodes of the reference capacitors having the shape of identical half rings, and the electrodes of the measuring capacitors have the same shape, each of two electrically connected half rings of different radius and each half are made ltso disposed symmetrically relative to the membrane diameter, and a semicircle with a large radius of the ground of the measuring capacitor and a half-ring with a smaller radius further measuring capacitor are arranged on one side of the central part of the membrane, and a semicircle with a smaller radius of main measuring capacitor; oo, m and r>> lu. ^{g is a} small radius with a large radius. w. Noah condensate tra - on dzhui. j / ^ 7 ////// 77 ^ /// 77 // 777. 7/77 // 777777 \ /