Honeywell temperature probe assemblies are ideal for process manufacturers, Original Equipment Manufacturers (OEMs) and Engineering Procurement Construction (EPC) contractors for temperature measurement. Entire assembly is certified, not just the transmitter or sensor. Simplified regulatory compliance because the probe-transmitter assembly is treated as a single certified device.
SmartLine Temperature probe assemblies are installation-ready temperature measurement assemblies offered with Honeywell’s temperature transmitters, sensor heads, sensors, thermowells and process connections. They are available in four versions:
STT85A: Probe Assembly with STT850 transmitter
STT820: Rigid probe assembly
STT830: Threaded and socket weld thermowell assembly
STT840: Drilled and flanged thermowell assembly
Temperature probe assemblies save users time in terms of engineering, ordering and installation/commissioning since these come in ready to install, fully calibrated assemblies with global agency approvals such as FM, CSA, ATEX, and IECEx.
STT85A: Probe assembly with an integrated STT850 transmitter.
STT820: Rigid probe (no thermowell).
STT830: Threaded / socket-weld thermowell assembly.
STT840: Flanged (drilled and flanged) thermowell assembly.
Support for RTD (e.g., Pt100) or thermocouple sensors in all assembly variants.
Option to enter Callendar–Van Dusen (C–V D) coefficients directly into the transmitter for more precise calibration of RTDs.
Duplex (dual) sensor options: for differential, averaging, or redundant measurement.
Thermowells can be tapered or straight depending on model.
Flange thermowell designs support different flange sizes (e.g., 1″, 1.5″, 2″) and different pressure classes.
Thermowell material: commonly stainless steel (316) for durability.
The entire assembly (sensor + transmitter) is system-calibrated in the factory together. This can deliver better accuracy than separate calibration.
Multipoint calibration available with certificate (user can choose 2, 3, or 4 test points).
For RTDs: Class A accuracy by default.
For thermocouples: Class 1 standard accuracy.
Sensor break / open-circuit detection is built in.
Transmitter is capable of SIL2/3 (safety-integrity-level) when used with STT850 in STT85A assembly.
Assembly has global safety / agency approvals (e.g. FM, CSA, ATEX, IECEx), making them suitable for hazardous locations.
Communication options on the integrated STT850 (in STT85A) include Analog (4–20 mA), HART, DE (Digitally Enhanced), FOUNDATION Fieldbus (FF).
Local or remote display options: the assembly may include a basic or advanced LCD display; remote meters like RMA801 / RMA803 can also be used.