The most basic RTD measurement uses a two-wire RTD for temperature measurement. Shown below is a schematic and design for a two-wire RTD measurement with an ADC. A ratiometric measurement is created with the RTD as the input and a precision resistor as the reference input.
Device Features: 2/4 Differential or 3/7 Single-Ended. True Bipolar ± 2.5V or Unipolar 5V. Max Data Rate – 2kSPS. Low Noise PGA: 40nV @ G = 128. 50/60Hz Simultaneous Rejection Mode (20SPS)
This translates RTD resistance to a voltage level convenient for an ADC input. A precision current reference provides excitation and an instrumentation amplifier scales the signal. The design also uses a three wire RTD configuration to minimize errors due to wiring resistance.
SSZT510 Technical article | TI.com - Texas Instruments
In theory, temperature measurements using resistance temperature detectors (RTDs) should be simple: measure a temperature with an RTD that changes resistance with temperature, measure the resistance of the RTD, and convert that resistance to …
In a typical RTD measurement application, the ADS1148 and ADS1248 are configured in a ratiometric topology using the built-in IDAC current sources feeding through an external reference precision resistor.
Sep 24, 2011 · This circuit is designed for a 0-5V output for a 0-200C temperature span. Components R2, R3, R4, and R5 are adjusted to change the desired measurement temperature span and output.
There is an extensive portfolio of semiconductor sensing technologies that allow for new capabilities in efficiency, performance, and low-latency response in real-time control systems. Therefore, alternative temperature measurement methods and their corresponding advantages are discussed in this document.
This cookbook design describes a temperature measurement for a three-wire RTD using the ADS124S08. This design uses two matched IDAC excitation currents for lead-resistance cancellation.
This cookbook design describes a temperature measurement for a four-wire RTD using the ADS124S08. This design uses a ratiometric measurement for a PT100 type RTD with a temperature measurement range from –200°C to 850°C. The four-wire RTD measurement is the most accurate of the RTD wiring configurations
Use two different measurements to measure the RTD resistance and cancel the lead-resistance error. The first measurement of the ADC is measured across AIN1 and AIN2, with the lead resistances included.