Pressure Temperature Transmitter Honeywell Series STT820 - Rigid Probe Assembly STT 3000 Temperature Probe Assemblies

Nipple/Explosion Proof Union/Nipple Extension  Same benefits as the standard Nipple/Union/Nipple extension except with explosion proof union rated:  Class 1, Division 1 and 2, Groups A, B, C and D  Class 2, Division 1 and 2, Groups E, F and G  Class 3 Recommended when supplied with explosion proof connection heads.

Instructions
● Choose availability column based on mounting configuration.

● A dot (●) denotes unrestricted availability. A letter denotes restricted availability.

● Blank denotes unavailable - choose alternate. View Restrictions table.

● Select options and approvals from Tables.

Honeywell temperature probe assemblies are ideal for process manufacturers, Original Equipment Manufacturers (OEMs) and Engineering Procurement Construction (EPC) contractors for temperature measurement.​

​Temperature probe assemblies are installation-ready temperature measurement assemblies offered with any of Honeywell's temperature transmitters, sensor heads, sensors, thermowells and process connections. They are available in three versions-

• STT820: Rigid probe assembly

• STT830: Threaded and socket weld thermowell assembly

• STT840: Drilled and flanged thermowell assembly

Temperature probes 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.

STT820-171-00-ANE0-R1U020D-00-000

Model Number Breakdown:

Key Number:
STT820 - Rigid Probe Assembly

I) Transmitter Selection :
171 - Wired to STT171 (Analog)

II) Options:
00 - None

III) Housing and Meters:
ANE - General purpose aluminum, 1/2" NPT Conduit Entry
0 - No Integral Meter Supplied

IV) Sensor Type
R1 - 1 x Pt100 (IEC), 2-wire, -58F to 500F
U - Ungrounded
02- 2 in. Sensor Immersion Length
0 - No Fractional Inches Sensor Immersion Length
D - No Lead Length

V) Approvals:
00 - None

VI) Assembly Options:
000 - None

Thermowells must be carefully selected for processes where significant velocity is present.

By penetrating the process flow, the thermowell is subject to the stress and friction of the flow. This may set up a natural vibration in the well. If this is not done correctly, the vibration will be such that the well will shear off in the process. This can be especially troublesome in high velocity steam lines.

As the engineer needs to have the well deep enough into the process to accurately measure the temperature, the selection of the length and diameter of the well needs to be checked against the process to ensure that they are compatible. This is done through a calculation known as a Murdock. This calculation will determine whether a thermowell will be acceptable for the proposed process. The Von Karman Trail refers to the turbulent wake, which is formed as fluid flows past the thermowell.

A vibration frequency is determined by the diameter of the thermowell and the fluid velocity. Should this frequency equal the natural frequency of the thermowell it will cause the thermowell to vibrate to the point where it will break off? Therefore, it is important that the thermowell is designed to insure the natural frequency of the thermowell always exceeds the potential wake frequency