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
