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Yokogawa STLD-301-E/MTS/PD/DL/Z
Product Series: STLD301 Smart Temperature Transmitter
Product Introduction:
The STLD-301-E/MTS/PD/DL/Z is a 2-wire smart temperature transmitter featuring advanced process diagnostics (PD), user-configurable damping and linearization (DL), and ground terminal (Z). The “PD” option provides sensor fault detection, “DL” enables custom input linearization and output damping, and “Z” includes a dedicated grounding terminal for noise reduction.
Detailed content
Working Principle:
Identical to the STLD-301 base unit — the transmitter measures RTD or TC input, converts to temperature, and outputs a 4-20 mA signal. The PD function continuously monitors sensor resistance for open-circuit, short-circuit, and drift conditions. The DL function applies a user-defined linearization curve (up to 10 points) to the input and a configurable time constant (0-60 seconds) to the output for noise filtering.
Technical Specifications:
| Parameter | Value |
|---|---|
| Input Type | Pt100 (JIS), Pt1000 (JIS), Cu50, JPt100, Type K, J, T, E, R, S, B, N |
| Output | 4-20 mA DC (2-wire) + HART 7 |
| Accuracy | ±0.1% of span (RTD), ±0.2°C (TC) |
| Process Diagnostics (PD) | Open sensor detection, short circuit detection, sensor drift warning |
| Damping/Linearization (DL) | Input: 10-point linearization; Output: 0-60 s damping |
| Ground Terminal (Z) | Dedicated chassis ground terminal for EMI reduction |
| Power Supply | 12-45 V DC (2-wire) |
| Ambient Temperature | -40°C to +85°C |
| Process Temperature | -200°C to +850°C |
| Protection Rating | IP66 / IP67 (NEMA 4X) |
| Ex Rating | Ex ia IIC T6 Ga / Ex d IIC T6 Gb |
| SIL Rating | SIL 2 (per IEC 61508) |
| Housing Material | Aluminum alloy with epoxy coating |
| Process Connection | SUS316L, 1/2″ NPT or G1/2″ |
Advantages:
- Process diagnostics provide early warning of sensor degradation
- 10-point linearization corrects non-linear sensor characteristics without external signal conditioners
- Adjustable output damping eliminates signal noise from control loops
- Dedicated ground terminal (Z) significantly improves EMC performance
- Single transmitter replaces multiple signal conditioning devices
Applicable Industries:
Same as STLD-301-PA — additionally suited for applications requiring sensor health monitoring such as critical process heating, reactor temperature control, and batch process monitoring
Installation Requirements:
- Connect the Z terminal to a clean earth ground point
- For PD function to operate correctly, ensure sensor wiring is intact and properly connected
- When using linearization, upload the correction table via HART communicator before commissioning
- Damping setting should match the process dynamics — too high a value will cause sluggish control response
Usage Notes:
- Use the HART communicator to configure the 10-point linearization table
- PD diagnostics require a minimum loop current of 3.8 mA to operate — verify loop power budget
- The Z terminal must be connected to earth ground for the EMI benefit to be effective
- Periodically review diagnostic logs for early sensor fault detection
