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Modern PRTD Temperature Sensors and High-Resolution Delta-Sigma ADCs Enable Wide Range High-Accuracy Temperature Measurements

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描述

Introduction

This article explains how to achieve high-performance precision, wide-range temperature measurement for platinum resistance temperature detectors (PRTDs), using a data-acquisition system (DAS) comprised of a delta-sigma analog-to-digital converter (ADC) and a modern processor. This DAS offers high performance, yet is cost effective. The development DAS presented here resolves design and mathematical challenges quickly and achieves precision temperature measurement in the PRTD's maximum range (-200°C to +850°C). Platinum resistance temperature detectors, or PRTDs, are absolute temperature-sensing devices that can assure repeatable measurements over temperature ranges of -200°C to +850°C. Platinum, moreover, is very stable and not affected by corrosion or oxidation. PRTDs thus provide optimal performance for precision industrial and medical applications that require precise temperature measurements.1 PRTDs are nearly linear devices. Depending on the temperature range and other criteria, you can make a linear approximation by calculating the PRTD resistance change over a temperature range of -20°C to +100°C.1 For a wider temperature range (-200°C to +850°C) and for higher accuracy, however, the temperature-measurement PRTD standard (EN 60751:2008) defines the behavior of platinum resistance versus temperature by a nonlinear mathematical model called the Callendar-Van Dusen equation. Years ago, implementation of such algorithms could present both technical and cost constraints in DAS design. Today's modern processors like the MAXQ2000 and affordable PCs can resolve these challenges quickly and cost effectively, while providing the user with a friendly graphical display. The Callendar-Van Dusen equation can be used in such a modern DAS to reduce errors to negligible levels for the wide -200°C to +850°C dynamic range. Accuracy will be ±0.3°C or better can be achieved.

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设计,建造,测试

图中的电路板已完全组装并经过测试。不可出售。

 

Maxim设备 (3)

器件号 名称 产品线 购买 设计套件和评估模块
MAX3420E USB外设控制器,SPI接口 控制器/扩展器 立即购买 设计套件
MAXQ2000 低功耗LCD微控制器 微控制器(MCU) 立即购买 设计套件
MAX11200 24位、单通道、超低功耗、Σ-Δ ADC,具有GPIO 模/数转换器(ADC) 立即购买 设计套件

Maxim设备 (3)

器件号 产品线
控制器/扩展器
USB外设控制器,SPI接口
微控制器(MCU)
低功耗LCD微控制器
模/数转换器(ADC)
24位、单通道、超低功耗、Σ-Δ ADC,具有GPIO

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