The Development Of Manganin Ultra-high Pressure Gauges

Under pressure, the value of resistance of manganin is well linear with the appliedpressure, and manganin silk has a larg sensitivity and pressure-resistance coefficient.So manganin pressure gauges are mainly used to measure and monitor ultra-highpressure in defense and war industries etc. High precision ultra-high pressure gaugewas investigated using manganin silk for pressure sensing unit in the project, whichwill be used for transfer standard of ultra-high pressure measuring instruments withliquid transmission medium.Firstly, the body of the manganin pressure gauge is manufactured by40CrNiMoAor40CrMnSiMoVA alloy steel treated by the fit heat treatment process. According thetensile strength, yield strength and fracture toughness, the reasonable structure of thebody is designed through the calculation of ideal strength, which reduces thedimension and improves the reliability.Secondly, we researched the measures of the manufacture of the manganin pressuresensing. Wind the manganin silk for spiral spring, then place and fit in the spiralgroove, and weld the electrodes with the spiral manganin silk. So the sensing unit isfinished. Push the sensing unit and the insulation film into the electrical lead-throughconductor base with ultra-high pressure resistance and high temperature resistance.Pack the sensing unit with bellow tube and connector which is welded to the base.The pressure measurement unit is packaged, and then assembled into the body ofmanganin pressure gauge.Before the sensing unit is isolated, it was should beannealed at the temperature of140℃, which makes the resistance of the sensing unitstable and decreases the zero drift. Then the sensing unit will be overloaded upto1400MPa pressure by placing it into pressure vessel with much higherpressure-resistance, which can improve the linearity and decrease the elastichysteresis in the measurement range. So the accuracy of manganin pressure gauge wasenhanced.After the measurement and research,we found the accuracy of the ultra-highpressure isolated manganin pressure gauge in the project is inferior is better than class0.1, and the annual stability is better than0.1%FS (Full Scale). So the manganinpressure gauge has success to achieve the objectives and satisfy with the demand oftransfer standard. The new model manganin electric resistance pressure gauge can beused for the monitoring and the measuring of the parameter of ultra-high pressure primary standard, which is beneficial to the accuracy and reliability of measuringparameter.