M12TX-PT100 Inline Temp. Transmitter for PT100 RTDs

Supported Applications

The Omega M12TX Series consists of analog, PC-programmable 2-wire transmitters designed for temperature measurement using 3-wire Pt100 RTD sensors. The series is engineered for industrial environments where space constraints require a compact form factor with direct mounting capability on the sensor via an integrated M12 thread design.

Key application characteristics include:

• Sensor Interface: Designed specifically for 3-wire Pt100 (alpha symbol 0.00385) RTD inputs.
• Configuration Method: Programmable via a computer using the M12TX-CONFIG-SET kit, which includes USB interface hardware and software compatible with Windows® 10.0 or higher.
• Mounting Style: Features an integrated connection allowing direct mounting onto sensors in space-limited areas.

Operating Conditions & Performance

The M12TX Series operates within a defined environmental envelope and delivers specific performance metrics for temperature signal conditioning. The transmitter electronics are rated for ambient temperatures from -40 to 80°C (-40 to 176°F) with relative humidity up to 100%.

• Measurement Range: Configurable input span between -50 and 800°C. Standard factory default range is typically set for 0 to 150°C (32 to 302°F).
• Accuracy: Transmitter accuracy is specified as Max. ±0.2°C or ±0.2% of span. The Pt100 sensor element meets Class A standards in accordance with IEC751 up to 300°C.
• Response Time: Output response time (90%) is less than 50 ms for the transmitter electronics. Thermal response times vary by probe configuration: M12TXC-PT100-3MM* and M12TXSS models achieve <3.5 sec; diameters of 6 mm reach <13 sec.
• Power Supply: Operates on 8.5 to 32 Vdc with polarity protection.

Configuration Options

The series offers configurable parameters and physical options tailored to specific installation requirements, including sensor error compensation, fault monitoring behavior, and environmental sealing.

• Housing & Protection: Available with thermoplastic material bodies or AISI 316L stainless steel (M12TXSS). Enclosure ratings include IP65 and IP67 in accordance to IEC60529. EMC compliance is provided per EN 61326.
• Process Connections: Features M12x1 male connectors for output and M12x1 female connectors for input (in accord with VDE0627). Some configurations support thermowells or compact mineral insulated sheaths made of AISI 316L.
• Fault Monitoring: Sensor break monitoring is selectable during configuration to trigger upscale (>21.0 mA) or downscale (<3.6 mA) actions. Sensor short-circuit action is fixed at downscale (<3.6 mA).
• Output Signal: Provides a 4+20 mA signal with a permissible load of 700Ω @24Vdc (calculated as R_load = (U - 8.5) / 0.022). The system is non-isolated between input and output.
• Configuration Options: Users can set the temperature range, measurement unit (°C/°F/°K), sensor error compensation over one or two spans, and assign an identifying name to the transmitter.

Key Product Differences

The M12TX Series includes distinct model families differentiated by body material, probe type, and dimensional specifications:

• M12TX-PT100-* (Thermoplastic): Features a thermoplastic body with compact mineral insulated AISI 316L probes. Compatible connections include PR-22 and RTD-M12 series.
• M12TXC-PT100-3MM-*: Designed for specific probe diameters (e.g., Ø3 mm) with thermoplastic bodies and AISI 316L thermowells. Factory default range is typically 0 to 100°C.
• M12TXSS: Constructed entirely of AISI 316L stainless steel for the body, offering enhanced durability in specific environments. Includes M12x1 connections and Ø15 or Ø16 dimensions depending on configuration.