SU1411571A1 - Method of setting up integrated circuit strain gauge bridges from stabilized current source - Google Patents

Abstract

The invention relates to a measurement technique, in particular, to manufacturing methods and {{tgeneral strain gauge bridges, and can be used in individual adjustment of strain gauges designed to operate at variable temperatures. The purpose of the invention is to improve the measurement accuracy under the conditions of varying temperatures by stabilizing the initial level of the signal of the tensome bridge, which is achieved by measuring the initial level of the signal and the resistance of the diagonal of the power supply of the tensome bridge with two different in the mode of supplying the besomost with a stabilized voltage with a subsequent calculation of the required value of the initial voltage level and fitting it by breaking the bridges 7 or 8 of the compensation resistor 5 or 6 made of the same material as the resistors 1, 2, 3 or 4 of the strain gauge. The choice of resistor 5 or 6 is determined by the signs of voltage drop and resistance of the strain gauge as a function of temperature. The method allows to increase the measurement accuracy and simplify the operation of the recording equipment. 1 il. (L with

Description

7- / 7

ate

,

The invention relates to a measuring technique, in particular to methods for manufacturing integral strain gauge-iloB, and can be used when individually adjusting the strain gauge 11 to the process of controlling their temperature 5 (: characteristics.

The aim of the invention is to improve the measurement accuracy in variable temperature conditions by It, by stabilizing the strain gauge signal obtained by adjusting the initial level, which is achieved by measuring the initial signal level and the resistance of the diagonal power supply diagonal at two different temperatures li power mode stabilized voltage followed by calculating the required value of the initial level and fitting by breaking the jumpers (the resistance of the compensation resistor made from the same Container material as the other resistors tensor Jost, to a value, it creates

required voltage.

The drawing shows the technology of the integral tensometer designed to be set up by the proposed method, before the start of the adjustment process ..

Integral strain gauge contains four working resistors 1-4, you- 1 | filled, for example, of silicon with the appropriate type of conductivity and located on the periphery of the circular membrane of the pressure sensor, two compensation resistors 5 and 5 of this; | all materials, made in the form of -; ((1) areas, shunted

1 1 and 7 and 8, and conductive | The cuts 9 are with contact paddzads 10 representing the vertices of the diagonal bridge.

: The method is carried out as follows (Method.

Connect the power supply diagonal of the bridge bridge to the source with stabilized voltage, and measure the initial voltage of the test bridge signal at two different temperatures. Simultaneously, ifipH the same temperatures are determined (The resistance of the bridge bridge power diagonal. The obtained data is substituted into the formula to calculate the required output voltage level

) -y (T1.)

infill) to (ta)

(one)

where and is the calculated value of the tablars at the output of the measuring diagonal of the tensome bridge, which ensures the stabilization of the initial level of the tensome bridge signal from temperature;

and (t)

and Ud) is the voltage at the output of the measuring diagonal of the tensome bridge at temperatures T and T .;

R (TI)

and Rd) are the resistances of the diagonal of the supply of the strain bridge at temperatures T and T.

Then, one of the two compensation resistors 5 or 6 located in the adjacent shoulders of the tensome bridge is fitted, the choice of resistor 5 or 6 being determined by the signs of a departure from the temperature of the initial voltage level and resistance of the tensometre. To do this, in accordance with the selected parameter characterizing the value of the compensation resistor 5 or 6, the voltage at the output of the measuring diagonal of the strain gauge is disconnected, alternately jumper 7 or 3 until the observed value of the voltage at the output becomes equal to the accepted tolerance for the discreteness of the fitting of the resistance value calculated by the formula (1). This completes the configuration of the integral tensometer and is ready for operation under the conditions of variable temperature.

Using the proposed method allows to increase the accuracy of the measurement of physical parameters in the presence of such an influencing factor as temperature varying with time. This reduces the additive component of the error of the strain gauge as a function of temperature, and simplifies its operation, since the initial signal level from the strain gauge remains constant and does not require adjustment of the subsequent recording equipment.

Formula

and 3

gaining

The method of setting the integral tensomesv with power from the source. stabilized current, which consists in measuring the initial level of the bridge signal at two different temperatures, determine by a calculation the parameter characterizing

the resistance value of the compensation resistor added to one of the bridge shoulders, depending on the sign of the additive temperature sensitivity of the bridge, and by breaking the jumpers that short the individual parts of the compensation resistor, set the required value of this parameter, in order to improve the accuracy of the measurement x effects of variable temperatures due to stabilization of the strain gauge signal obtained by setting the initial level, the initial signal level of the strain gauge at two x different temperatures are measured in the mode tenzo.mosta power from the constant-voltage at these same temperatures cases determined by the resistance of diagonally tenzomosta power, and as a parameter indicative of a compensation resistance value of the resistor made from the same mate

o

n

five

rial, as other resistors of the strain bridge, use the calculated value of the voltage at the output of the strain gauge when it is powered from a source of stabilized voltage, obtained by the formula

..U (T4) -U (Ti)

- кТт7Т R (fp:

where and is the calculated value of the voltage at the output of the measuring diagonal of the tensome bridge, ensuring the stabilization of the initial signal level from temperature;

and (t,),

and (Tj) is the voltage at the output of the measuring diagonal of the tensome bridge at temperatures T, and

R (T,),

R (Tj) is the resistance of the supply diagonal of the strain bridge at temperatures T, and T.,

Claims (1)

Claim The resistance of the diagonal of the strain bridge supply. The obtained data is substituted into the formula for calculating the required output voltage level (1) The way to configure integrated strain gages powered by a stabilized current source, which consists in measuring the initial signal level of the bridge at two different temperatures, by calculating the parameter that characterizes the resistance value of the compensation resistor added to one of the bridge arms depending on the sign of the additive temperature the sensitivity of the bridge, and by breaking the jumpers shorting the individual sections of the compensation resistor, set the required value of this pair, meter, characterized in that, in order to improve the measurement accuracy under the influence of variable temperatures due to stabilization obtained when setting the initial level of the strain gage signal, the initial level of the strain gage signal at two different temperatures is measured in the power mode of the strain gage from the stabilized voltage source, at the same temperatures, jq is determined by the resistance of the diagonal of the strain gage power supply, and as a parameter characterizing the value of the resistance of the compensation resistor made From the same material as other tensor bridge resistors, they use the calculated value of the voltage at the tensor bridge output when it is powered from a stabilized voltage source, obtained by the formula _n _U (T ₄ ) -U (Ti) ^and - “Ш7У ---- - ' ^1p th (tr: where U is the calculated value of the voltage at the output of the measuring diagonal of the strain gage, providing stabilization of the initial signal level from temperature; and (t,), U (T ₂ ) - voltage at the output of the measuring diagonal of the tensor bridge at temperatures T, and IL; R (T _t ), Rd ^) are the resistances of the diagonal of the strain bridge power supply at temperatures T, and T _g .