METHOD TO TUNE STRAIN-GAUGE SENSORS WITH BRIDGE MEASUREMENT CIRCUIT BY MULTIPLICATIVE TEMPERATURE ERROR WITH ACCOUNT OF POSITIVE NON-LINEARITY OF TEMPERATURE CHARACTERISTIC OF OUTPUT SIGNAL OF SENSOR Russian patent published in 2014 - IPC G01B7/16 

FIELD: measurement equipment.

SUBSTANCE: determine (TSC) of a bridge circuit α⁺ _do and α^- _do at temperature t⁺ and t^-, corresponding to upper and lower limit of the working temperature range, non-linearity of bridge circuit TSC (Δα_do=α⁺ _do-α^- _do). If the produced value Δα_do is positive, they convert positive non-linearity of bridge circuit TSC into the negative one by inclusion of a heat-independent resistor R_αinp. For this purpose they determine input resistance and TSC of input resistance, and the input value of TSC value, and the input resistance, TSC of resistance strain gauges α⁺ _d and α^- _d at temperature t⁺ and t^-, calculate non-linearity of bridge circuit TSC (Δα_d=α⁺ _d-α^- _d). If α⁺ _d and Δα^- _d are in the field of conversion of positive non-linearity of bridge circuit TSC into the negative one, they calculate the nominal value of the resistor R_αinp. They connect the resistor R_αinp into the diagonal of the bridge circuit power supply. The TCS of the bridge circuit is defined at the temperature t⁺ and t^-, non-linearity of the bridge circuit TCS is calculated as Δα_do. If Δα_do takes the negative value, then compensation of multiplicative temperature error is carried out with account of negative non-linearity of bridge circuit TSC by inclusion of a heat independent resistor R_αoutp, shunted with the heat-independent resistor R_doutp, into the output diagonal of the bridge circuit at the load resistance R_l≤2 kOm.

EFFECT: higher accuracy of compensation.

3 tbl, 3 dwg