RU2013132578A - INDIRECT METHOD FOR ADJUSTING TENZOR RESISTANCE SENSORS WITH A BRIDGE MEASURING CIRCUIT BY MULTIPLICATIVE TEMPERATURE ERROR WITH ACCOUNT FOR NEGATIVE NONLINEARITY OF TEMPERATURE DATA - Google Patents

Abstract

1. An indirect way to configure strain gauge sensors with a bridge measuring circuit based on a multiplicative temperature error, taking into account the negative non-linearity of the temperature characteristic of the sensor output signal, which consists in checking the affiliation of the temperature sensitivity coefficient (TFC) of the bridge circuit and its non-linearity of the application of the method if the TCR of the bridge circuit and its nonlinearity belong to the field of application of the method, then include a resistor Rin the output diagonal of the bridge circuit, the output resist the phenomenon of which is shunted by a thermally independent resistor R, characterized in that before checking the affiliation of the DC circuit bridge and its non-linearity of the application of the method, a thermally dependent technological resistor R is installed in the output diagonal of the sensor bridge circuit, the value of which is greater than the possible values of the resistance of the compensation resistor R, in parallel with which a jumper is installed, measure the output resistance of the bridge circuit of the sensor R, connect the sensor to a low-impedance load with a resistance R = 2 · R, measure the value Using the initial unbalance U ,, at normal temperature t, as well as temperatures t and t corresponding to the upper and lower limits of the operating temperature range, respectively, measure the output signal of the sensor U ,, at the nominal value of the measured parameter and temperatures t, t, t, respectively, calculate the deviations the sensor output signal ΔU ,, corresponding to the temperatures t, t and t, the sensor is connected to a low-resistance load with resistance, the initial unbalance values are measured, at temperatures t, t, t, respectively, as well as the values

Claims (2)

1. An indirect way to configure strain gauge sensors with a bridge measuring circuit by a multiplicative temperature error, taking into account the negative non-linearity of the temperature characteristic of the sensor output signal, which consists in verifying the belonging of the temperature sensitivity coefficient (TCR) of the bridge circuit and its non-linearity of the application of the method if the TCR of the bridge circuit and its nonlinearity belong to the field of application of the method, then include a resistor R _α in the output diagonal of the bridge circuit, the output copro the voltage of which is shunted by a thermally independent resistor R _w , characterized in that before checking the affiliation of the DC circuit bridge and its non-linearity of the application of the method, a thermally dependent technological resistor R _αt is installed in the output diagonal of the sensor bridge circuit, the value of which is greater than the possible values of the resistance of the compensation resistor R _α , in parallel to which install a jumper, measure the output resistance of the bridge circuit of the sensor R _o , connect the sensor to a low-impedance load with a resistance R _n = 2 · R _o , measure the values of the initial imbalance U _0н , $$U_{0nt}^{+}$$

, $$U_{0nt}^{-}$$

at normal temperature t ₀ , as well as temperatures t ⁺ and t ^- , corresponding to the upper and lower limits of the operating temperature range, respectively, measure the output signal of the sensor U _out , $$U_{\mathrm{at}sxnt}^{+}$$

, $$U_{\mathrm{at}sxnt}^{-}$$

when the nominal value of the measured parameter and temperatures t ₀ , t ⁺ , t ^- respectively, calculate the deviation of the output signal of the sensor ΔU _out , $$\Delta U_{\mathrm{at}sxnt}^{+}$$

, $$\Delta U_{\mathrm{at}sxnt}^{-}$$

corresponding to temperatures t ₀ , t ⁺ and t ^- , the sensor is connected to a low-impedance load with resistance $$R_n^{\text{'}\text{'}}=R_{\mathrm{at}sx}$$

measure the values of the initial unbalance $$U_{0n}^{\text{'}\text{'}}$$

, $$U_{0nt}^{\text{'}\text{'}+}$$

, $$U_{0nt}^{\text{'}\text{'}-}$$

at temperatures t ₀ , t ⁺ , t ^- respectively, as well as the values of the sensor output signal $$U_{\mathrm{at}sxn}^{\text{'}\text{'}}$$

, $$U_{\mathrm{at}sxnt}^{\text{'}\text{'}+}$$

, $$U_{\mathrm{at}sxnt}^{\text{'}\text{'}-}$$

, at the nominal value of the measured parameter and temperatures t ₀ , t ⁺ and t ^- respectively, the deviations of the sensor output signal are calculated $$\Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}$$

, $$\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}+}$$

, $$\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}-}$$

corresponding to temperatures t ₀ , t ⁺ and t ^- , calculate the DC-link TCD and the temperature coefficient of resistance (TCR) of the output resistance of the bridge circuit at t ⁺ and t ^- , solving the system of equations: $$\{\begin{array}{c}{\alpha }_{d\mathrm{about}\text{ism}}^{+}=\frac{R_n\left(\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}+}-\Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\right)+R_{\mathrm{at}sx}\left[\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}+}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)-\Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\right]}{\left(R_n^{\text{'}\text{'}}+R_{\mathrm{at}sx}\right)\cdot \Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\cdot \Delta t^{+}}\\ {\alpha }_{\mathrm{at}sx\text{ism}}^{+}=\frac{R_n+R_{\mathrm{at}sx}}{R_{\mathrm{at}sx}}\cdot \frac{\Delta U_{\mathrm{at}sxn}\left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{+}\cdot \Delta t^{+}\right)-\Delta U_{\mathrm{at}sxnt}^{+}}{\Delta U_{\mathrm{at}sxnt}^{+}\cdot \Delta t^{+}}\end{array}$$

$$\{\begin{array}{c}{\alpha }_{d\mathrm{about}\text{ism}}^{-}=\frac{R_n\left(\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}-}-\Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\right)+R_{\mathrm{at}sx}\left[\Delta U_{\mathrm{at}sxnt}^{\text{'}\text{'}-}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{-}\cdot \Delta t^{-}\right)-\Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\right]}{\left(R_n^{\text{'}\text{'}}+R_{\mathrm{at}sx}\right)\cdot \Delta U_{\mathrm{at}sxn}^{\text{'}\text{'}}\cdot \Delta t^{-}}\\ {\alpha }_{\mathrm{at}sx\text{ism}}^{-}=\frac{R_n+R_{\mathrm{at}sx}}{R_{\mathrm{at}sx}}\cdot \frac{\Delta U_{\mathrm{at}sxn}\left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{-}\cdot \Delta t^{-}\right)-\Delta U_{\mathrm{at}sxnt}^{-}}{\Delta U_{\mathrm{at}sxnt}^{-}\cdot \Delta t^{-}}\end{array}$$

Where $${\alpha }_{d\mathrm{about}\text{ism}}^{+}$$

, $${\alpha }_{d\mathrm{about}\text{ism}}^{-}$$

- TKH bridge circuit at temperatures t ⁺ and t ^- respectively; $${\alpha }_{\mathrm{at}sx\text{ism}}^{+}$$

, $${\alpha }_{\mathrm{at}sx\text{ism}}^{-}$$

- TCS output resistance of the bridge circuit at temperatures t ⁺ and t ^- respectively; Δt ⁺ = t ⁺ -t ₀ - positive temperature range; Δt ^- = t ^- -t ₀ - negative temperature range; calculate the nonlinearity of the DC circuit of the bridge circuit $$\Delta {\alpha }_{d\mathrm{about}\text{ism}}={\alpha }_{d\mathrm{about}\text{ism}}^{+}-{\alpha }_{d\mathrm{about}\text{ism}}^{-}$$

; remove a jumper to process temperature-dependent resistor R _αt, the sensor is connected to a low impedance load resistance R _{of n} = 2 · R _O measured initial unbalance U _0αn, U _0αnt, U _0αnt at temperatures t _0, t ^+, t ^-, respectively, and the output sensor signal U _o $$U_{\mathrm{at}sx\alpha nt}^{+}$$

, $$U_{\mathrm{at}sx\alpha nt}^{-}$$

at the nominal value of the measured parameter and temperatures t ₀ , t ⁺ , t ^- respectively, the deviations of the sensor output signal ΔU _o $$\Delta U_{\mathrm{at}sx\alpha nt}^{+}$$

, $$\Delta U_{\mathrm{at}sx\alpha nt}^{-}$$

corresponding to temperatures t ₀ , t ⁺ and t ^- , calculate the TCS of the thermally dependent resistor R _αt at temperatures t ⁺ and t ^- according to the formulas: $${\alpha }_{\mathrm{to}\text{ism}}^{+}=\frac{R_n+R_{\mathrm{at}sx}+R_{\alpha t}}{R_{\alpha t}}\cdot \frac{\Delta U_{\mathrm{at}sx\alpha n}\cdot \left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{+}\cdot \Delta t^{+}\right)}{\Delta U_{\mathrm{at}sx\alpha nt}^{+}\cdot \Delta t^{+}}-\frac{R_n+R_{\mathrm{at}sx}\cdot \left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)+R_{\alpha t}}{R_{\alpha t}\cdot \Delta t^{+}}$$

; $${\alpha }_{\mathrm{to}\text{ism}}^{-}=\frac{R_n+R_{\mathrm{at}sx}+R_{\alpha t}}{R_{\alpha t}}\cdot \frac{\Delta U_{\mathrm{at}sx\alpha n}\cdot \left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{-}\cdot \Delta t^{-}\right)}{\Delta U_{\mathrm{at}sx\alpha nt}^{-}\cdot \Delta t^{-}}-\frac{R_n+R_{\mathrm{at}sx}\cdot \left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{-}\cdot \Delta t^{-}\right)+R_{\alpha t}}{R_{\alpha t}\cdot \Delta t^{-}}$$

, Where $${\alpha }_{\mathrm{to}\text{ism}}^{+}$$

, $${\alpha }_{\mathrm{to}\text{ism}}^{-}$$

- TCS of the resistor R _αt at temperatures t ⁺ and t ^- respectively; after checking the affiliation of the DC-link bridge circuit and its non-linearity of the scope of the method and before installing the resistors R _α and R _w in the output diagonal of the bridge circuit, when the DC-link DC link and its nonlinearity of the field of application of the method calculate the values of the resistors R _α and R _ш , solving the system of equations: $$\{\begin{array}{c}\begin{array}{l}\frac{(\left[R_n+R_{\alpha }\right)\left(R_{\mathrm{at}sx}+R_w)+R_{\mathrm{at}sx}\cdot R_w\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)+R_w\right]\left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{+}\cdot \Delta t^{+}\right)}{\left(R_{\mathrm{at}sx}+R_w\right)\{\left[R_n+R_{\alpha }\left(\mathrm{one}+{\alpha }_{\mathrm{to}\text{ism}}^{+}\cdot \Delta t^{+}\right)\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)+R_w\right]+R_{\mathrm{at}sx}\cdot R_w\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)\}\Delta t^{+}}-\frac{\mathrm{one}}{\Delta t^{+}}=\\ =\frac{(\left[R_n+R_{\alpha }\right)\left(R_{\mathrm{at}sx}+R_w)+R_{\mathrm{at}sx}\cdot R_w\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{-}\right)+R_w\right]\left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{-}\cdot \Delta t^{-}\right)}{\left(R_{\mathrm{at}sx}+R_w\right)\{\left[R_n+R_{\alpha }\left(\mathrm{one}+{\alpha }_{\mathrm{to}\text{ism}}^{-}\cdot \Delta t^{-}\right)\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{-}\cdot \Delta t^{-}\right)+R_w\right]+R_{\mathrm{at}sx}\cdot R_w\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{-}\cdot \Delta t^{-}\right)\}\Delta t^{-}}-\frac{\mathrm{one}}{\Delta t^{-}};\end{array}\\ \frac{(\left[R_n+R_{\alpha }\right)\left(R_{\mathrm{at}sx}+R_w)+R_{\mathrm{at}sx}\cdot R_w\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)+R_w\right]\left(\mathrm{one}+{\alpha }_{d\mathrm{about}\text{ism}}^{+}\cdot \Delta t^{+}\right)}{\left(R_{\mathrm{at}sx}+R_w\right)\{\left[R_n+R_{\alpha }\left(\mathrm{one}+{\alpha }_{\mathrm{to}\text{ism}}^{+}\cdot \Delta t^{+}\right)\right]\left[R_{\mathrm{at}sx}\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)+R_w\right]+R_{\mathrm{at}sx}\cdot R_w\left(\mathrm{one}+{\alpha }_{\mathrm{at}sx\text{ism}}^{+}\cdot \Delta t^{+}\right)\}\Delta t^{+}}-\frac{\mathrm{one}}{\Delta t^{+}}=0.\end{array}$$

2. The method according to claim 1, characterized in that after calculating the values of the compensation resistors R _α and R _W include a temperature-dependent resistor R _α with the calculated value by partially _{activating the} technological resistor R _αt .