3-Channel Thermocouple Temperature Measurement System with 0.25 В° C Accuracy (CN0172)

The function of the circuit shown in Figure 1 is to provide a high accuracy multichannel thermocouple measurement solution. Achieving a precision thermocouple measurement requires a signal chain of precision components that amplifies the small thermocouple voltage, reduces noise, corrects nonlinearity, and provides accurate reference junction compensation (commonly referred to as cold junction compensation). This circuit addresses all these challenges for measuring thermocouple temperature with better than ±0.25°C accuracy.


The circuit shown in Figure 1 shows how three K type thermo-couples are connected to the AD7793 precision 24-bit sigma-delta (Σ-Δ) analog-to-digital converter (ADC) to measure the thermocouple voltage. Because the thermocouple is a differential device rather than an absolute temperature measurement device, the reference junction temperature must be known to get an accurate absolute temperature reading. This process is known as reference junction compensation, commonly referred to as cold junction compensation. In this circuit, the ADT7320 precision 16-bit digital temperature sensor is used for the cold junction reference measurement and provides the required accuracy.


This type of application is popular where a cost-effective, accurate temperature measurement is required over the wide temperature ranges offered by thermocouples.


Figure 1. Multichannel Thermocouple Measurement System (Simplified Schematic: All Connections and Decoupling Not Shown)

Возможности

  • 3 channel K-type thermocouple measurement system
  • Typical temperature range of -200 C to +1200 C
  • Highly accurate temperature measurement to 0.25 degrees
  • 16-bit digital temperature sensor used for cold junction compensation

Файлы

3-Channel Thermocouple Temperature Measurement System with 0.25 В° C Accuracy  CN0172

Используемые компоненты

Производитель: Analog Devices Inc.
Наименование
Производитель
Описание Корпус/
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Цена, руб. Наличие
ADT7320UCPZ
ADT7320UCPZ
Analog Devices Inc.
Арт.: 572214 ИНФО RD
Поиск
предложений
±0.25°C Accurate, 16-Bit Digital SPI Temperature Sensor
ADT7320UCPZ
-
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предложений
ADT7320UCPZ-R2
ADT7320UCPZ-R2
Analog Devices Inc.
Арт.: 572215 ИНФО PDF RD
Доступно: 1534 шт.
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условия
поставки
±0.25 Accurate, 16-Bit Digital SPI Temperature Sensor
ADT7320UCPZ-R2
1534 шт.
(под заказ)
Выбрать
условия
поставки
ADT7320UCPZ-RL7
ADT7320UCPZ-RL7
Analog Devices Inc.
Арт.: 572216 ИНФО RD
Доступно: 10108 шт.
Выбрать
условия
поставки
±0.25°C Accurate, 16-Bit Digital SPI Temperature Sensor
ADT7320UCPZ-RL7
10108 шт.
(под заказ)
Выбрать
условия
поставки