Precision temperature measurement in heat and cold meters

PT100/500/1000 Resistance Temperature Detectors (RTDs) are widely used in grid infrastructure and factory automation applications where high precision temperature measurement is often required. Technical requirements include either 20 mK precise Differential Temperature Measurement (DTM) for heat and cold meters from 0 to 180°C or better than 400 mK precision over the full range of -200 to 850°C for industrial sensor transmitters. This training will cover a system-level deep-dive on how using TI’s ADS1220 Delta-Sigma converter family enables precise temperature measurement in heat and cold meter applications with standard RTDs.

The 24-bit ADS1220 family of devices offers an ultra-low power, single-chip precision temperature solution for measuring up to two 2- or 4-wire RTDs in series, achieving up to 19.6 bits of effective resolution, better than 10 mK resolution and 20 mK accuracy of the DTM. Using either SPI, I2C or UART interface the ADS1220 devices can be connected to TI's MSP430FR6989 (rotation detection sensing) or MSP430FR6047 (ultrasonic flow measurement) MCUs, completing a heat or cold meter development platform.

TMP116 is a fully digital, high-precision temperature sensor, which is more accurate than the Class AA RTDs in the -55 to +125°C range with a single-point calibration. TMP116 integrates 64 bits of user data for storing calibration data and eliminates the paperwork between PT sensor and heat meter vendors.

The 2x2 mm TMP116 digital sensor with I2C interface can be built into a standard PT sensor body and connect directly to the heat or cold meter MCU such as MSP430 or CC13xx wireless MCU families. TI's TPD1E04 or TPD1E10B devices ensure compliance with EN61000-4-2 and -4-4, as required by the EN1434-4 heat meter norm.