A Precision Resistance Generator for the Calibration of RTD-Based Temperature Instruments
Pan Hui Chen, Li Guo, Gu Bing Lu, Chuan Jin · Applied Mechanics and Materials · 2014
A new calibration method for RTD-based temperature instrument is introduced. The precision resistance is generated using digital-controlled relays to switch a precision resistance network which is similar to the resistance box. We also present a new switch algorithm to reduce the influence of initial error of the precision resistors. The resistance of the precision resistance generator varies from 80.00ohms to 260.00ohms with a 4-wire output interface. It is convenient that using this precision resistance generator to test the nonlinear of temperature transmitters based on Pt100. Our test shows that the generator can provide a precision resistance with an uncertainty of less than ±0.02ohms.