A Rosemount temperature-transmitter model number is a sequence of required positions followed by optional ordering codes. The sequence matters because the early positions determine which later rows remain available. A dual-sensor requirement, output protocol, housing, and approval should be settled before someone starts copying option letters into a requisition.
The Rosemount Temperature Transmitter Configurator assembles 644 and 3144P candidates from copied ordering rows, then decodes its own result before showing it. That round trip catches missing positions and unparsed characters. It does not replace the current product data sheet, Configuration Data Sheet, or instrument review.
1. How the two model codes are structured
The 644 begins with the fixed model prefix 644. Position 1 is one character for transmitter type: head, field, or rail mount, with single or dual sensor input. Position 2 is one character for transmitter output. Published option codes follow those required positions.
The 3144P begins with the fixed prefix 3144P. Position 1 is a two-character housing style. Position 2 is a one-character output. Position 3 is a one-character measurement configuration for single sensor, dual sensor, or current X-well rows. Published options follow.
| Family | Required sequence | What follows |
|---|---|---|
| 644 | 644 + type (1) + output (1) | Approval, enclosure, diagnostics, display, calibration, filter, and other options |
| 3144P | 3144P + housing (2) + output (1) + measurement configuration (1) | Approval, display, calibration, dual-input, X-well, and other options |
2. Make the dual-sensor decision first
Hot Backup needs two sensor inputs. On the 644, diagnostics code DC requires type S for a dual-sensor head mount or type T for a dual-sensor rail mount. On the 3144P, dual-input code U1 requires measurement configuration 2.
This is not a late option that can turn a single-input transmitter into a dual-input transmitter. If automatic failover or sensor-drift comparison is part of the requirement, choose the dual-sensor required position before completing the rest of the code.
3. Choose HART, FOUNDATION Fieldbus, or PROFIBUS PA before the options
For the 644, HART output A is used across head, field, and rail mount rows. FOUNDATION Fieldbus F and PROFIBUS PA W are limited by the copied ordering rule to type H, the single-sensor head mount. Dual-sensor, field-mount, and rail-mount 644 types use HART in the copied table.
For the 3144P, HART A and FOUNDATION Fieldbus F have different option sets. HART diagnostics, HART revisions, software configuration C1, current X-well rows, and several certifications do not carry into the Fieldbus path. Fieldbus control A01 and diagnostics D01 require Fieldbus output. Pick the control-system protocol before walking the option list.
4. Head mount, field mount, and rail mount on the 644
Types H and S are DIN A head-mount transmitters. Types F and D are field-mount transmitters. Types R and T are rail-mount transmitters. The type also states whether the unit has one sensor input or two.
The rail rows come from Rosemount 644 Rail Mount PDS 00813-0300-4728 Rev AA, December 2021. That document is older than the February 2026 head and field PDS used for the other 644 rows. Rail units clip to DIN rail and do not take the head or field enclosure codes. They also use a shorter approval and accessory set. Confirm every rail order against the current rail document.
5. What X-well means on the 3144P
Current Rev TH uses measurement configuration 3 for an X-well assembly with sensor and mounting, and configuration 4 for a transmitter-only X-well-capable build. Configuration 3 needs C1, HR7, TR1, a pipe-mount design row, and MC1 in the copied ordering rules.
X-well depends on pipe, sensor, mount, insulation, process, and configuration details. Treat the resulting model code as a monitoring configuration, not as control-loop, custody-transfer, SIS, or installation approval. Confirm the application against current Emerson X-well instructions.
6. Worked example: 644HANAJ6F6
| Segment | Code | Meaning | Source |
|---|---|---|---|
| Model | 644 | Rosemount 644 Temperature Transmitter | PDS 00813-0100-4728 Rev WH |
| Transmitter type | H | DIN A head mount, single sensor input | Page 6 |
| Transmitter output | A | 4-20 mA with digital signal based on HART Protocol | Page 7 |
| Approval | NA | No approval | Page 7 |
| Enclosure | J6 | Universal junction box, 2 entries, aluminum, 1/2-14 NPT, 3 in. (76 mm) diameter | Page 8 |
| Line filter | F6 | 60 Hz line voltage filter | Page 10 |
The code carries no sensor. A 644H does not tell you whether the point uses a Pt 100 RTD or a type K thermocouple, and it does not carry the range. Read those values from the Configuration Data Sheet or the assembled sensor model string.
7. Grammar-derived dual-sensor example
3144PD1A2I5M5Q4U1 decodes as a 3144P with D1 aluminum dual-compartment field housing and 1/2-14 NPT entry, HART output, dual-sensor measurement configuration, I5 USA intrinsically safe and non-incendive approval, M5 LCD display, Q4 calibration certificate, and U1 Hot Backup. The string was assembled from the published rows and decoded cleanly through the copied grammar on July 27, 2026.
The example does not prove hazardous-area fit, sensor configuration, availability, or installation suitability. Check the certificate, current PDS, and instrument data sheet.
8. What the model code does not tell you
The normal 644 or 3144P transmitter model code does not identify the sensor type, range, span, damping, variable mapping, or the configured values behind option C1. Those values live on the device, the instrument data sheet, the Configuration Data Sheet, or an assembled sensor model string.
An approval code identifies an ordered approval row. It does not prove that the certificate covers the actual area classification, wiring method, ambient temperature, or complete installation. Keep the model string with the project documents, but review the full application before purchase or installation.
9. Sources
- Rosemount 644 Temperature Transmitter Product Data Sheet 00813-0100-4728, Rev WH, February 2026, ordering pages 6 through 13.
- Rosemount 644 Rail Mount Temperature Transmitter Product Data Sheet 00813-0300-4728, Rev AA, December 2021, ordering page 4.
- Rosemount 3144P Temperature Transmitter Product Data Sheet 00813-0100-4021, Rev TH, February 2026, ordering pages 5 through 16.
- Rosemount 644 HART Head Mount Configuration Data Sheet 00806-0100-4728, Rev EH, April 2021.
Confirm final selections against the current revisions.