STT170 Smart Temperature Transmitter

STT170 is a measurement solution for temperature monitoring applications. It helps end users and Original Equipment Manufacturers (OEMs) achieve reliable and accurate temperature measurement in a cost-effective manner. Part of Honeywell’s lower-cost “SmartLine” temperature transmitter family. Designed to provide reliable temperature measurement in a cost-effective way.

The STT170 is Honeywell’s economy-tier family of temperature transmitters to flank the existing mid-tier STT700 and high-tier STT750 & STT850 temperature transmitters. It helps convert low level signals from temperature sensors such as RTDs and TCs into current signals and is capable of transmitting long distances through noisy plant environments. The STT170 line consists of three temperature transmitters and one configuration tool:

STT171 – Analog output, RTD-only sensor input

STT173 – Analog output, RTD or thermocouple sensor input

STT17H – HART output, RTD & thermocouple sensor input

STT17C – PC-based configuration tool for configuring the STT171, STT173 and STT17H transmitters

Models / Variants

STT171: 4–20 mA analog output, supports RTD (resistance) or ohm input.

STT173: 4–20 mA, supports RTD, thermocouple (T/C), ohm, or mV input.

STT17H: HART + 4–20 mA output; supports RTD, T/C, ohm, or mV; can take single or dual sensors (difference or average).

STT17F: (in some spec sheets) supports FOUNDATION Fieldbus protocol.

STT17C: PC-based configuration tool for configuring the above transmitters.

Signal Linearization

The transmitter automatically linearizes the temperature signal between the user-defined lower range value (LRV) and upper range value (URV).

Alarms for Sensor Failure

Programmable high and low limit alarms to detect sensor errors (for example, open circuit).

Sensor error response meets NAMUR NE 43 standard.

Input Options

Supports a wide variety of sensors: RTDs, thermocouples, resistance (ohm), and mV, depending on the model.

Dual-sensor input for the HART model (STT17H) — can measure difference or average.

Isolation

Some models (e.g., STT173, STT17H, STT17F) have galvanic (electrical) isolation to reduce interference.

Mounting / Packaging Options

Very compact size — fits in a little DIN Form B head-mount housing.

Field-mount housing options are also available.

Communication / Output Options

Analog 4–20 mA for basic models.

Digital HART communication in HART model (STT17H).

For fieldbus model, supports FOUNDATION Fieldbus (in STT17F).

Features

  • Configurable via the STT17C tool using a PC.
  • For HART model (STT17H), you can also configure via a HART handheld communicator.
  • Typical smart transmitter power: requires DC supply; for HART models, common supply range is 8-30 VDC. (Not always in summary, but standard for such transmitters; check datasheet.)
  • More accurate and reliable than simple direct-wired sensors because of signal conditioning and linearization.
  • Helps reduce wiring costs and noise-related issues by converting sensor signal near the sensor.