FSI TF907814-001 Temperature Probes | 907814-001 2233R024S74 LA658 871-324-12C 949-658-00/B

Technical Dossier

Product Details And Specifications

FSI TF907814 Series: Comprehensive Temperature Probe Range and Technical Overview

The FSI (Fluid Sensors International) TF907814 series represents a family of industrial-grade thermocouple and RTD-based temperature probes engineered for continuous-duty service in high-temperature process environments. These probes are installed across global heavy industry sectors including petrochemical refining, glass manufacturing furnaces, steel reheat furnaces, cement kilns, and nuclear auxiliary systems. The TF907814-001 variant — cross-referenced as 907814-001, 2233R024S74, LA658, 871-324-12C, and 949-658-00/B — is specifically configured as a Side Bowl Temperature Probe, designed for radial insertion into combustion chambers or bowl-type furnace sidewalls to deliver accurate zone temperature feedback to DCS and PLC control loops.

These probes are integral to burner management systems (BMS) and process temperature control architectures. Their signal outputs are typically wired into distributed control systems (DCS) such as Honeywell TDC 3000, Yokogawa CENTUM, Emerson DeltaV, and ABB 800xA, where they serve as primary process variables (PV) for PID loop control.

The Evolution of TF907814 Architecture

The TF907814 probe series was developed to address the limitations of early ceramic-sheathed thermocouples in high-vibration, high-temperature sidewall applications. Early-generation probes in this class used bare-wire Type K or Type S thermocouples with ceramic insulators, which were prone to mechanical failure under thermal cycling. The TF907814 architecture introduced a mineral-insulated metal-sheathed (MIMS) construction with a compacted MgO insulation core, significantly improving response time, mechanical robustness, and EMI immunity.

As DCS platforms evolved from analog 4–20 mA signal highways to HART-enabled and fieldbus-compatible architectures (FOUNDATION Fieldbus, PROFIBUS PA), the TF907814 series was adapted with transmitter-ready head assemblies. Later revisions incorporated dual-element configurations (primary + backup sensing element) to support SIL-rated safety instrumented systems (SIS) without requiring probe replacement during element failure.

The series has entered its mature/end-of-production lifecycle. FSI no longer manufactures new units under the original part numbers. Procurement is now exclusively through authorized aftermarket distributors and MRO spare parts suppliers. Long-term maintenance support — including cross-reference matching, dimensional verification, and functional equivalence certification — is the primary service requirement for facilities still operating equipment fitted with TF907814-series probes.

TF907814 Full Catalog & Functionalities (SKU List)

The following SKUs represent confirmed part numbers within the FSI TF907814 temperature probe family, organized by configuration and application type:

Primary Probe Assemblies (Side Bowl / Radial Insertion)

TF907814-001: Side bowl radial insertion probe, single-element, Type K thermocouple, MIMS sheath, standard process connection.
TF907814-002: Side bowl radial insertion probe, dual-element (primary + backup), Type K, MIMS sheath, SIL-2 compatible.
TF907814-003: Side bowl probe, Type S (Pt/Rh) thermocouple, high-temperature variant up to 1600°C, ceramic head.
TF907814-004: Side bowl probe, Type N thermocouple, oxidizing atmosphere service, Inconel 600 sheath.
TF907814-005: Side bowl probe, Pt100 RTD, 4-wire configuration, low-temperature process service to 600°C.

Replacement Sensing Elements (Insert Assemblies)

907814-001: OEM replacement insert element for TF907814-001 assembly, Type K, 24-inch insertion length.
907814-002: Replacement insert, Type K, 36-inch insertion length, extended reach configuration.
907814-003: Replacement insert, Type S, high-temperature ceramic-insulated, 18-inch insertion length.
2233R024S74: FSI internal revision code for TF907814-001 with 24-inch sheath, S74 terminal head assembly.
LA658: OEM cross-reference number (likely Forney/original equipment manufacturer alias) for TF907814-001 assembly.

Connection Head & Transmitter Assemblies

871-324-12C: Terminal head assembly, cast aluminum, IP65, 1/2-inch NPT conduit entry, compatible with TF907814 probe bodies.
949-658-00/B: Revision B transmitter head assembly, 4–20 mA HART output, DIN rail or head-mount, for TF907814 series probes.
TF907814-010: Complete assembly with integrated HART transmitter, loop-powered, configured for DCS analog input cards.
TF907814-011: Complete assembly with FOUNDATION Fieldbus H1 transmitter, for FF-compatible DCS segments.
TF907814-020: Thermowell and probe combined assembly, 316 SS thermowell, 3/4-inch NPT process connection, 150 lb flange option.
TF907814-021: Thermowell assembly only, Inconel 600, for high-corrosion or high-velocity process fluid service.

Calibration & Certification Variants

TF907814-001-CAL: Factory-calibrated TF907814-001 with NIST-traceable calibration certificate, ±0.5°C accuracy class.
TF907814-003-CAL: Factory-calibrated Type S variant with IEC 60584 Class 1 certification documentation.

Sourcing Hard-to-Find & Obsolete TF907814 Parts

The TF907814 series is no longer in active production. Facilities operating furnaces, kilns, or combustion systems fitted with these probes face a common MRO challenge: the original FSI part numbers are discontinued, and direct OEM replacement is unavailable through standard distribution channels.

DriveKNMS maintains a dedicated inventory program for obsolete and hard-to-find industrial instrumentation, including the TF907814 family. Our sourcing capabilities include:

- Cross-reference matching across all known alias part numbers (907814-001, 2233R024S74, LA658, 871-324-12C, 949-658-00/B) to identify functional equivalents.
- Dimensional and specification verification against original FSI engineering drawings to confirm fit, form, and function before shipment.
- New-old-stock (NOS) units sourced from decommissioned plant inventories and authorized surplus channels.
- Functional equivalent substitution with documented equivalence reports for engineering approval workflows.
- Emergency same-day quotation for unplanned outage scenarios.

Quality Control for the TF907814 Range

Temperature probes in the TF907814 series present specific quality verification challenges due to their MIMS construction, dual-element configurations, and integrated transmitter head assemblies. DriveKNMS applies the following test protocol to all TF907814-series units prior to shipment:

- Insulation Resistance (IR) Test: Megohmmeter test at 500 VDC between sensing element and sheath. Minimum acceptance: 1000 MΩ at ambient temperature per IEC 60584.
- Continuity & Element Resistance Check: Four-wire Kelvin measurement of thermocouple or RTD element resistance to verify element integrity and detect open/short circuits.
- Thermoelectric Output Verification: Comparison measurement against NIST-traceable reference standard at two calibration points (ice point 0°C and elevated process temperature).
- Sheath Integrity Inspection: Visual and dimensional inspection of MIMS sheath for corrosion, mechanical deformation, or end-seal compromise.
- Head Assembly Pressure Test: IP65 ingress protection verification for terminal head and transmitter assemblies.
- HART Communication Test: For transmitter-equipped variants (TF907814-010, 949-658-00/B), full HART command set verification including PV, SV, loop current, and device status registers.

All test results are documented and available upon request as part of the shipment package.