Online calibration of a temperature measurement point

Abstract

A system for measuring temperature includes a thermowell, a primary temperature sensor, a reference sensor, and a transmitter. The thermowell has a measurement instrument connection and a side port. The primary temperature sensor extends into the thermowell through the measurement instrument connection, and the reference sensor extends into the thermowell through the side port. The transmitter is connected to each of the primary temperature sensor and the reference sensor. The transmitter has circuitry for measuring temperature based upon signals received from the primary temperature sensor and for concurrently calibrating based upon signals received from the reference sensor.

Description

technical field [0001] The present invention relates to temperature measurement and, in particular, to the calibration of temperature measurement points. Background technique [0002] Temperature measurement points are used in the process control industry to sense, for example, the temperature of a process fluid. A temperature measurement point typically includes a temperature sensor connected to a transmitter. Transmitters are typically located in remote locations and can be connected to the control room via a 4-20 mA current loop, a digital communication bus, or a wireless network. A temperature sensor is placed in thermal contact with the process fluid and provides an output related to the temperature of the process fluid. The temperature sensor, for example, may be a resistance temperature detector (RTD), which is a temperature dependent resistor, or a thermocouple, which is a device that produces a temperature dependent voltage. With a typical RTD, the transmitter in...

AI Technical Summary

Problems solved by technology

Therefore, calibration can be expensive, preventing users from calibrating temperature measurement points as often as they should be

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