Non-saturating integrator for enhanced dynamic range thermal power measurement in Microcalorimetry

Non-saturating integrator for enhanced dynamic range thermal power measurement in Microcalorimetry

Článek WoS

Traditional microcalorimeters face challenges due to their limited dynamic range and saturation from multistage amplification, which hinders the precise detection of signals with large variations. This paper introduces a novel, non-saturating integrator-based system that overcomes these limitations by combining sigma-delta modulation with a sample-and-hold stage and a digital extrapolation algorithm. This design bypasses saturation constraints, enabling continuous signal tracking under varying thermal loads. Modeling predicts a temperature dynamic range of ti 9.54 mu K to ti 9.51 K under noise-free conditions, demonstrating the system's linearity across a wide thermal input range. Experimental results show a temperature resolution of ti 0.50 mK and a power resolution of ti 167.3 nW, consistent with noise and quantization limits. The system's calibrated responsivity reaches ti 1.44 MV & sdot;W-1, in alignment with theoretical and simulated values. This represents an increase of up to three orders of magnitude in usable dynamic range compared to conventional amplification. Experimental validation, including H2O evaporation and KCl crystallization tests, confirms the system's ability to resolve subtle thermal changes and low-level heat variations over extended time periods, with a deviation of ti 2.55 % from theoretical H2O evaporation enthalpy. The system's oversampling capability enables accurate analog-to-digital conversion without high-power analog-to-digital converters, preventing thermal interference. This non-saturating integrator offers enhanced speed, stability, and miniaturization potential for diverse calorimetric applications, including lab-on-a-chip and point-of-care systems.

Traditional microcalorimeters face challenges due to their limited dynamic range and saturation from multistage amplification, which hinders the precise detection of signals with large variations. This paper introduces a novel, non-saturating integrator-based system that overcomes these limitations by combining sigma-delta modulation with a sample-and-hold stage and a digital extrapolation algorithm. This design bypasses saturation constraints, enabling continuous signal tracking under varying thermal loads. Modeling predicts a temperature dynamic range of ti 9.54 mu K to ti 9.51 K under noise-free conditions, demonstrating the system's linearity across a wide thermal input range. Experimental results show a temperature resolution of ti 0.50 mK and a power resolution of ti 167.3 nW, consistent with noise and quantization limits. The system's calibrated responsivity reaches ti 1.44 MV & sdot;W-1, in alignment with theoretical and simulated values. This represents an increase of up to three orders of magnitude in usable dynamic range compared to conventional amplification. Experimental validation, including H2O evaporation and KCl crystallization tests, confirms the system's ability to resolve subtle thermal changes and low-level heat variations over extended time periods, with a deviation of ti 2.55 % from theoretical H2O evaporation enthalpy. The system's oversampling capability enables accurate analog-to-digital conversion without high-power analog-to-digital converters, preventing thermal interference. This non-saturating integrator offers enhanced speed, stability, and miniaturization potential for diverse calorimetric applications, including lab-on-a-chip and point-of-care systems.

Sigma-delta integration, Non-saturating integrator, Microcalorimeter, Thermal power measurement, Dynamic range enhancement, Flexible printed circuit board calorimeter

Sigma-delta integration, Non-saturating integrator, Microcalorimeter, Thermal power measurement, Dynamic range enhancement, Flexible printed circuit board calorimeter

ZHANG, Y.; ZHU, H.; LU, H.; XIANG, Z.; BRODSKÝ, J.; GABLECH, I.; NEUŽIL, P.

2026

31.03.2026

Elsevier

MEASUREMENT

267

3

Spojené království Velké Británie a Severního Irska

12

https://www.sciencedirect.com/science/article/pii/S0263224126001144